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This chapter describes starting up and configuring the Cisco CMTS for the first time. The chapter contains the following sections:
Before you power on and configure the Cisco CMTS:
After these prerequisites are met, you are ready to configure the Cisco CMTS. This includes, at a minimum, configuring a host name and password for the Cisco CMTS and configuring the CMTS to support IP over the cable plant and network backbone.
The Cisco CMTS is administered using the Cisco command interpreter, called the EXEC. Boot and log in to the router before you can enter an EXEC command, following this procedure:
Step 2 Power on the Cisco CMTS. The following prompt is displayed:
Would you like to enter the initial dialog?[yes]:no
Step 3 Enter no to choose the normal operating mode of the router. The user EXEC prompt displays:
Router>
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Note For security purposes, the EXEC has two levels of access to commands: user EXEC mode and privileged EXEC mode. The commands available at the user level are a subset of those available at the privileged level. |
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Tips Because many privileged-level EXEC commands are used to set operating parameters, password-protect these commands to prevent unauthorized use. |
At the EXEC prompt, enter one of the following two commands to set password protection:
To gain access to privileged-level commands, enter the correct password.
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Note An enable secret password can contain from 1 to 25 uppercase and lowercase alphanumeric characters. An enable password can contain any number of uppercase and lowercase alphanumeric characters. A number cannot be the first character. Spaces are valid password characters; for example, "two words" is a valid password. Leading spaces are ignored. Trailing spaces are recognized. Alphanumeric characters are recognized as uppercase or lowercase. |
Passwords should be different for maximum security. If you enter the same password for both during the setup script, the system will accept it, but you will receive a warning message indicating that you should enter a different password.
This section describes how to recover a lost enable or console login password, and how to replace a lost enable secret password on your Cisco CMTS.
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Note It is possible to recover the enable or console login password. The enable secret password is encrypted, however, and must be replaced with a new enable secret password. |
Following is an overview of the general steps in the password recovery procedure:
Step 2 Press the Break key to get to the bootstrap program prompt (ROM monitor). You might need to reload the system image by power cycling the router.
Step 3 Change the configuration register so the following functions are enabled: Break; ignore startup configuration; and boot from Flash memory.
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Note The key to recovering a lost password is to set the configuration register bit 6 (0x0040) so that the startup configuration (usually in NVRAM) is ignored. This will allow you to log in without using a password and to display the startup configuration passwords. Cisco recommends setting the configuration register to 0x142. |
Step 4 Power cycle the router by turning power OFF and then back ON.
Step 5 Log in to the router and enter the privileged EXEC mode.
Step 6 Enter the show startup-config command to display the passwords.
Step 7 Recover or replace the displayed passwords.
Step 8 Change the configuration register back to its original setting.
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Note To recover a lost password if Break is disabled on the router, you must have physical access to the router. |
Complete the following steps to recover or replace a lost enable, enable secret, or console login password:
Step 2 Configure the terminal to operate at 9600 baud, 8 data bits, no parity, and 2 stop bits.
Step 3 If you can log in to the router as a nonprivileged user, enter the show version command to display the existing configuration register value. Note the value for use later.
If you cannot log in to the router at all, continue with the next step.
Step 4 Press the Break key or send a Break from the console terminal.
rommon n>), where n is the number of the command line. Proceed to Step 6.
Step 5 Within 60 seconds of restoring the power to the router, press the Break key or send a Break. This action causes the router to enter the ROM monitor and display the ROM monitor prompt (rommon 1>).
Step 6 To set the configuration register on a Cisco CMTS, use the configuration register utility by entering the confreg command at the ROM monitor prompt as follows:
rommon 1> confreg
Answer yes to the enable "ignore system config info?" question and note the current configuration register settings.
Step 7 Initialize the router by entering the reset command as follows:
rommon 2> reset
The router will initialize, the configuration register will be set to 0x142, and the router will boot the system image from Flash memory and enter the System Configuration dialog (setup) as follows:
--- System Configuration Dialog --
Step 8 Enter no in response to the System Configuration dialog prompts until the following message is displayed:
Press RETURN to get started!
Step 9 Press Return. The user EXEC prompt is displayed as follows:
Router>
Step 10 Enter the enable command to enter the privileged EXEC mode. Then enter the show startup-config command to display the passwords in the configuration file as follows:
Router# show startup-config
Step 11 Scan the configuration file display looking for the passwords; the enable passwords are usually near the beginning of the file, and the console login or user EXEC password is near the end. The passwords displayed will look something like this:
enable secret 5 $1$ORPP$s9syZt4uKn3SnpuLDrhuei
enable password 23skiddoo
.
.
line con 0
password onramp
The enable secret password is encrypted and cannot be recovered; it must be replaced. The enable and console passwords can be encrypted or clear text. Proceed to the next step to replace an enable secret, console login, or enable password. If there is no enable secret password, note the enable and console login passwords if they are not encrypted and proceed to Step 16.
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Caution Do not perform the next step unless you have determined you must change or replace the enable, enable secret, or console login passwords. Failure to follow the steps as presented here could cause your router configuration to be erased. |
Step 12 Enter the configure memory command to load the startup configuration file into running memory. This action allows you to modify or replace passwords in the configuration.
Router# configure memory
Step 13 Enter the privileged EXEC command configure terminal to enter configuration mode:
Router# configure terminal
Step 14 To change all three passwords, enter the following commands:
Router(config)#enable secret newpassword1
Router(config)#enable password newpassword2Router(config)#line con 0
Router(config)#password newpassword3
Change only the passwords necessary for your configuration. You can remove individual passwords by using the no form of the above commands. For example, entering the no enable secret command will remove the enable secret password.
Step 15 You must configure all interfaces to be not administratively shut down as follows:
Router(config)#interface fast ethernet 0/0
Router(config)#no shutdown
Enter the equivalent commands for all interfaces that were originally configured. If you omit this step, all interfaces will be administratively shut down and unavailable when the router is restarted.
Step 16 Use the config-register command to set the configuration register to the original value noted in Step 3 or Step 7.
Step 17 Press Ctrl-z or type end to exit configuration mode:
Router(config)# end
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Caution Do not execute the next step unless you have changed or replaced a password. If you skipped Step 12 through Step 15, skip to Step 19. Failure to observe this will cause you to erase your router configuration file. |
Step 18 Enter the copy running-config startup-config command to save the new configuration to nonvolatile memory:
Router# copy running-config startup-config
Step 19 Enter the reload command to reboot the router:
Router# reload
Step 20 Log in to the router with the new or recovered passwords.
You can configure the Cisco CMTS using procedures in one of the following sections:
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Note These sections provide minimal configuration instructions. For additional configuration information, refer to "Understanding System Operations." For examples of Cisco CMTS configuration files, refer to the "Viewing Sample Configuration Files" section. |
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Tips Be sure you have appropriate addresses and values based on your network before you attempt to configure the router. Enter the show version command to display the release of Cisco IOS software on your router. |
For Cisco CMTS components, the slot number is the chassis slot in which a port adapter or a cable modem card is installed. The logical interface number is the physical location of the interface port on a port adapter. Numbers on a Cisco CMTS begin with 0. Using a Cisco uBR7246 to illustrate, slot/port positioning is as follows:
To configure the system, define the Cisco CMTS interfaces, using the interface type slot/port commands:
Configuring Cisco cable modem cards is particularly important because these components serve as the cable TV RF interfaces. Configuration involves the following for each interface:
Router (config-int) # cable downstream frequency down-freq-hz
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Note This command has no effect on the external upconverter, which actually sets the downstream frequency. Noting the correct value for the cable modem card, however, provides useful information for troubleshooting. |
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Tips The digital carrier frequency is not the same as the video carrier frequency. For EIA channel 95, the video carrier frequency is 91.250 MHz which is 1.75 MHz below the center frequency. |
Router (config-int) # no shutdown
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Tips The valid range for a fixed upstream frequency is 5,000,000 Hz to 65,000,000 Hz for the MC16E cable modem card. The valid range for all other cable modem cards that support NTSC operations is 5,000,000 Hz to 42,000,000 Hz. |
Router (config-int) # cable upstream port frequency up-freq-hz
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Note Ensure that the selected upstream frequency does not interfere with the frequencies used for any other upstream applications in your cable plant. |
Router (config-int) # no cable upstream port shutdown
Router# show running-config
Router# copy running start
The Media Access Control (MAC)-layer or hardware address is a standardized data link layer address required for certain network interface types. These addresses are not used by other devices in the network; they are specific and unique to each port. The Cisco CMTS uses a specific method to assign and control the MAC-layer addresses for port adapters.
To support OIR, an address allocator with a unique MAC address is stored in an EEPROM on the universal broadband router midplane. Each address is reserved for a specific port and slot in the router regardless of whether a port adapter or a cable modem card resides in that slot.
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Note Port adapter and cable modem card slots maintain the same slot number regardless of whether other port adapters or cable modem cards are installed or removed. However, when you move a port adapter or cable modem card to a different slot, the logical interface number changes to reflect the new slot number. |
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Caution When "hot swapping" a port adapter or cable modem card with a different type of component (for example, an MC11 FPGA with an MC11C, or an MC16B with an MC16C), you might have to reconfigure the interfaces. Refer to the Hardware Installation Guide that came with your CMTS or to the appropriate FRU document for more specific information regarding online insertion and removal (OIR). |
The MAC addresses are assigned to the slots in sequence. The first addresses are assigned to port adapter slot 0 and slot 1, and the next addresses are assigned to port adapter slot 2 through cable modem card slot 6. This address scheme allows you to remove port adapters or cable modem cards and insert them into other universal broadband routers without causing the MAC addresses to move around the network or be assigned to multiple devices.
Storing the MAC addresses for every slot in one central location means the addresses stay with the memory device on which they are stored.
As of the date of this publication, the following Cisco cable modem cards can be installed in a Cisco CMTS:
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Note All C version cards support all DOCSIS modulation and symbol rates. Refer to Table 2-1 for a list of DOCSIS supported data rates and modulation schemes. Because the FPGA version of the MC11 card supports only one upstream modulation and channel width, you cannot define an upstream modulation profile for the card. The default modulation profile 1 cannot be changed when using the FPGA version of the MC11 card. |
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Note The B version card excludes support of 256 QAM downstream and 16 QAM upstream support at two of the five DOCSIS upstream symbol rates—2.56 M and 1.28 M. Refer to Table 2-1 for a list of DOCSIS supported data rates and modulation schemes. |
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Note While most Cisco cable modem cards transmit downstream signals to upconverters using a 44 MHz frequency, the MC16E transmits downstream IF signals to an upconverter using the 36.125 MHz frequency. Only the MC16E cable modem card supports full 8 MHz operation. |
The cable modem cards can be configured in a number of different upstream combinations based on the card used, your cable network, and the anticipated subscription and service levels. Table 2-1 shows the DOCSIS and EuroDOCSIS data rates.
| Upstream Channel Width | Modulation Scheme | Baud Rate Sym/sec | Raw Bit Rate Mbit/sec |
|---|---|---|---|
3.2 MHz | 16 QAM | 2.56 M | 10.24 |
1.6 MHz | 16 QAM | 1.28 M | 5.12 |
800 kHz | 16 QAM | 640 K | 2.56 |
400 kHz | 16 QAM | 320 K | 1.28 |
200 kHz | 16 QAM | 160 K | 0.64 |
To display information about a specific cable modem card slot's downstream channel, use the show interfaces cable command with the CM card's slot number and downstream port number in the following format: show interfaces cable slot/downstream-port [downstream].
Use the slot number and downstream port number to display information about a downstream interface. You can abbreviate the command to sh int c. The following example illustrates the display for downstream channel port 0 in cable modem slot 3 of a Cisco uBR7246:
Router# sh int c 3/0 Cable3/0 is up, line protocol is upHardware is CMTS, address is 0009.0ed6.ee18 (bia 0009.0ed6.ee18 Internet address is 1.1.1.1/24 MTU 1500 bytes, BW 27000 Kbit, DLY 1000 usec, rely 255/255, load 1/255 Encapsulation MCNS, loopback not set, keepalive not set ARP type: ARPA, ARP Timeout 04:00:00 Last input 00:00:00, output 00:00:00, output hang never Last clearing of "show interface" counters never Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 41000 bits/sec, 45 packets/sec 5 minute output rate 43000 bits/sec, 45 packets/sec
1616534 packets input, 184284660 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 1616534 packets output, 184284660 bytes, 0 underruns 0 output errors, 0 collisions, 0 interface resets 0 output buffer failures, 0 output buffers swapped out
To display information about a specific cable modem card slot's upstream channel, use the show interfaces cable command with the CM card's slot number, downstream port number, and upstream port number in the format of show interfaces cable slot/downstream-port [upstream] upstream-port. Use the slot number, downstream port number, and upstream port number to display information about an upstream interface. You can abbreviate the command to sh int c.
The following example shows the display for upstream channel port 0 in cable modem slot 3 of a Cisco uBR7246 that is turned up:
Router# sh int c 3/0 0 Cable6/0: Upstream 0 is upReceived 3699 broadcasts, 0 multicasts, 28586 unicasts 0 discards, 0 errors, 0 unknown protocol 21817 packets error-free, 2371 corrected, 8097 uncorrectable 0 noise, 0 microreflections CBR_queue_depth: [not implemented], ABR_queue_depth: [not implemented], UBR[1]_queue_depth: 0, UBR[2]_queue_depth: 0, UBR[3]_queue_depth: 0, POLLS_queue_depth: [not implemented] ADMIN_queue_depth: [not implemented] Last Minislot Stamp (current_time_base):190026 FLAG:1 Last Minislot Stamp (scheduler_time_base):200706 FLAG:1
Table 2-2 maps the cable modem card's interfaces and physical ports. The cards can be configured in a number of different upstream combinations.
| Cable Modem Card | Interface | Physical Ports |
|---|---|---|
MC11 | Cable N/0 | DS, US0 |
MC12 | Cable N/0 | DS, US0, US1 |
MC14 | Cable N/0 | DS, US0, US1, US2, US3 |
MC16 | Cable N/0 | DS, US0, US1, US2, US3, US4, US5 |
You can display information on a specific port adapter or all port adapters in the Cisco CMTS. To display information about all port adapter slots, use the show interfaces command. To display information about a specific port adapter slot, use the show interfaces command with the port adapter type and slot number in the format of show interfaces [type slot/port].
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Tips If you abbreviate the command (sh int) and do not specify the port adapter type and slot number (or arguments), the system interprets the command as show interfaces. The system displays the status of all port adapters, all cable modem cards, and all ports. |
R7732-01-uBR7246# sh int FastEthernet0/0 is administratively up, line protocol is up Hardware is DEC21140, address is 0000.0000.0000 (bia 0000.0000.0000) Internet address is 1.1.1.3
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, rely 255/255, load 1/255
(display text omitted)
Hssi1/0 is administratively down, line protocol is down Hardware is MIF68840_MM, address is 0000.0000.0000 (bia 0000.0000.0000)
Internet address is 1.1.1.0 MTU 4470 bytes, BW 100000 Kbit, DLY 100 usec, rely 255/255, load 1/255 (display text omitted) Ethernet2/0 is administratively up, line protocol is up
Hardware is AmdP2, address is 0000.0000.0000 (bia 0000.0000.0000) Internet address is 1.1.1.7 MTU 1500 bytes, BW 100000 Kbit, DLY 1000 usec, rely 255/255, load 1/255
(display text omitted) Cable3/0 is up, line protocol is up Hardware is CMTS, address is 0009.0ed6.ee18 (bia 0009.0ed6.ee18) Internet address is 1.1.1.1/24 MTU 1500 bytes, BW 27000 Kbit, DLY 1000 usec, rely 255/255, load 1/255 (display text omitted)
You can also use arguments such as the interface type (Ethernet, Fast Ethernet, ATM, serial, HSSI, Packet-over-SONET, and so forth) and the port address (slot/port) to display information about a specific port adapter interface only. The following example shows such a display:
R7732-01-uBR7246#sh int f1/0
FastEthernet1/0 is up, line protocol is up
Hardware is AmdFE, address is 0030.7bfa.a81c (bia 0030.7bfa.a81c)
Internet address is 111.0.1.18/30
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 100Mb/s, 100BaseTX/FX
ARP type:ARPA, ARP Timeout 04:00:00
Last input 00:00:01, output 00:00:02, output hang never
Last clearing of "show interface" counters never
Queueing strategy:fifo
Output queue 0/40, 0 drops; input queue 0/75, 0 drops
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
0 packets put, 230925 bytes
Received 146107 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog
0 input packets with dribble condition detected
0 packets put, 284529 bytes, 0 underruns
0 output errors, 0 collisions, 10 interface resets
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out
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Note The interface type in the show interfaces command must match the actual interface type of the port adapter. For example, if you enter sh int e 2/0 and a HSSI port adapter is actually in port adapter slot 2/0, the command will return an "invalid input" error. |
Cisco IOS release 12.1(3)EC support the Dynamic Upstream Modulation feature on the Cisco uBR-MC1xC and Cisco uBR-MC16S cable modem cards. Dynamic Upstream Modulation monitors the signal-to-noise-ratio (SNR) and forward error correction (FEC) counters in the active return path of each upstream port. It tracks whether the upstream channel signal quality can support the modulation scheme configured, and adjusts to the most robust modulation scheme when necessary. Dynamic Upstream Modulation improves service quality in Data Over Cable Service Interface Specification (DOCSIS) installations offering data, voice, or video services.
Noise in the upstream line from the consumer to the service provider degrades data transmission from the subscriber home. If the noise impairment is of substantial duration, it may cause the cable modem to temporarily lose communication with the headend facility altogether. As a contingency plan, Multiple Service Operators (MSOs) can reserve multiple upstream frequencies or channels for their subscribers so that if one channel suffers too much interference, the Cisco CMTS requests that the cable modems hop to another channel. This method of ingress avoidance is called frequency agility. The Dynamic Upstream Modulation feature in Cisco IOS Release 12.1(3)EC checks that the upstream signal can support the configured modulation scheme, and adjusts to a more robust modulation scheme if necessary. When return path conditions improve, it returns the upstream channel to the higher modulation scheme.
The upstream channel is characterized by many cable modems transmitting to the CMTS. These signals operate in a burst mode of transmission. Time in the upstream channel is slotted. The CMTS provides time slots and controls the usage for each upstream interval.
The Cisco CMTS equipment periodically broadcasts Upstream Channel Descriptor (UCD) messages to all cable modems. These messages define upstream channel characteristics including upstream frequencies, symbol rates and modulation schemes, FEC parameters, and other physical layer values.
Cisco supports all DOCSIS error correction encoding and modulation types and formats. Upstream signals are demodulated using Quadrature Phase Shift Keying (QPSK) or Quadrature Amplitude Modulation (16QAM). QPSK carries information in the phase of the signal carrier, whereas 16QAM uses both phase and amplitude to carry information.
Sending data reliably in the upstream direction is an issue because upstream spectrum varies greatly between cable plants. Select upstream parameters based on your cable plant's return paths.
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Tips Customize upstream profiles for maximum trade-off's between bandwidth, efficiency, and upstream channel robustness. For example, 16QAM requires approximately 7dB higher (channel to noise) C/N ratio to achieve the same bit error rate (BER) as QPSK, but it transfers information at twice the rate of QPSK. |
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Caution Upstream modulation profiles can be assigned to specific upstream ports based on the Cisco cable modem card used. Only those familiar with Data Over Cable Service Interface Specification (DOCSIS) who have received the proper training should create upstream modulation profiles. |
Dynamic Upstream Modulation uses modulation profiles to track upstream signal quality. A modulation profile is a collection of six burst profiles that are sent out in a UCD message to configure a modem's transmit parameters for the upstream message types: request, request/data, initial maintenance, station maintenance, short grant, and long grant.
The return path of several fiber nodes can be combined together at a single point to form a single RF frequency domain called a combiner group. The frequency hop table associated with a combiner group is called a spectrum group. Dynamic Upstream Modulation can be configured on interfaces with fixed upstream frequencies or on interfaces with assigned spectrum groups.
Dynamic Upstream Modulation can be used along with spectrum groups. If you are using the Cisco uBR-MC16S card, when Dynamic Upstream Modulation and spectrum groups are configured on the same interface, the modulation switchover is chosen as the first corrective action, followed by a frequency hop, and finally a reduction in channel width. For information on spectrum groups and the Cisco uBR-MC16S card, see Cisco uBR7200 Series MC16S Cable Modem Card Spectrum Management.
Based on the SNR estimate of the receiver circuitry and FEC correctable/uncorrectable thresholds of a particular upstream channel on an Cisco uBR-MC16C or Cisco uBR-MC16S cable modem card, the 16QAM channel can change automatically to a QPSK channel. You can enable or disable the SNR thresholds. On a Cisco uBR-MC16S cable modem card, you can enable or disable the automatic switch feature when spectrum management is on.
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Note The automatic switch of a 16QAM to QPSK feature is only available on Cisco uBR-MC16C and Cisco uBR-MC16S cable modem cards. |
For example, if you configure Dynamic Upstream Modulation on the Cisco CMTS using two modulation profiles 1 and 2.
where:
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Note Cisco recommends that the primary profile uses 16QAM modulation and the secondary uses QPSK, but this is optional. The two modulation profiles can both be QPSK or 16QAM. It is not mandatory that one is 16QAM and the other QPSK. But, modulation profile switchover is tied to 16QAM and QPSK thresholds. |
The criteria for modulation profile 1 to switch to modulation profile 2 (more robust modulation scheme) is:
The criteria for modulation profile 2 to switch to modulation profile 1 is:
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Note In the above example, modulation profile 1 switches to modulation profile 2 based on OR conditions. Modulation profile 2 switches to modulation profile 1 based on AND conditions. |
The Cisco CMTS handles frequency agility as follows:
Transitional assessment—When a channel quality state changes, the Cisco CMTS immediately checks other non-active channels provisioned for the serving group.
Periodic assessment—The Cisco CMTS performs a channel quality check of non-active channels in the serving group and attempts to reassign channels if there can be quality improvements.
The Cisco CMTS divides a cable plant into downstream channels that contain upstream segments. Each upstream segment typically serves more than one fiber node. Upstream segments can be defined as:
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Note A cable modem card supports either sparse or dense segments—not both. |
Defining sparse segments allows cable operators to share upstream bandwidth among fiber nodes with fewer subscribers. Defining dense segments allows cable operators to provide larger upstream bandwidth to fiber nodes with many subscribers. Figure 2-1 illustrates sparse versus dense segments. As Figure 2-1 shows, a downstream segment can contain multiple upstream segments. Two fiber nodes can be in one downstream segment, but in different upstream segments.
An upstream frequency has an associated upstream input power level in dBmV. Cable operators must make noise measurements and determine the cable plant's spectrum management policy. Different modulation schemes and symbol rates are used based on the cable plant characteristics and the cable modem card in the chassis. Bits are encoded into a two-dimensional mapping called a constellation.
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Note Good carrier-to-noise (C/N) ratio is needed to properly decode symbols into bits. |
The return path of several fiber nodes can be combined together at a single point to form a single RF frequency domain, called a combiner group. The Cisco CMTS software allows a frequency hop table to be associated with a combiner group, called a spectrum group.
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Note A combiner group refers to an RF topology point. A spectrum group refers to the frequency hop table associated with a combiner group. |
The Cisco uBR7200 series universal broadband routers support up to 32 spectrum groups. Each spectrum group defines the table of frequencies to be used in a specific frequency plan. Cisco cable modem cards interface the downstream and upstream ports to the cable plant, while port adapters connect to the IP backbone and external networks.
The Cisco CMTS software includes Cisco IOS commands that can be used to define upstream frequency hop tables. In the global and interface configuration modes, these are grouped under the cable spectrum-group command hierarchy. The steps to configure a spectrum group are as follows:
Due to the nature of CATV technology, upstream noise management is a significant issue. Two-way digital data signals are more susceptible than one-way signals to stresses in the condition of the HFC network. Degradation in video signal quality might not be noticeable in one-way cable TV service, but when two-way digital signals share the network with video signals, digital signals can be hampered by:
To adjust your return amplifiers and lasers, follow rigorous plant maintenance procedures documented in the NTSC Supplement on Upstream Transport Issues or appropriate cable plant standard. Also refer to the Hardware Installation Guide that came with your CMTS.
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Note The MC16S does not support 8-MHz operation. |
Measurement of noise power levels with a spectrum analyzer is a mandatory part of the setup procedure. Cisco recommends having fixed frequency settings during early deployment—at least until amplifier cascade adjustments or plant repair becomes infrequent for the nodes connected to the upstream port.
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Tips Upstream port frequency should be set to a fixed value during system installation, selected from the frequency plan for the RF domain of the RF plant segment connected to the upstream. When multiple upstream ports are combined together to provide increased bandwidth, care should be taken to prevent overlapping frequency bands. |
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Note The choice of spectrum is limited to bands having sufficient carrier-to-noise power ratio and carrier-to-ingress power ratio to support transmission of QPSK and QAM data.DOCSIS sets the minimum value for these parameters both to 25 dB in the 5-to-42 MHz frequency range for NTSC operations. Bands with known ingress should be avoided. Higher frequency bands are preferred due to harmonic relief of noise in many plants. |
When the system has reached sufficient stability, the RF domain topology can be entered into the Cisco IOS configuration file to enable RF spectrum management. This management feature—called spectrum groups described earlier—applies a common frequency management policy to a set of upstream ports.
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Note When each upstream port has its own RF domain, the group is called a non-shared spectrum group. When multiple upstream ports share the same RF domain, the group is called a shared spectrum group. |
In general, when defining your spectrum:
Using the Cisco CMTS cable modem cards and appropriate software images, you can configure the router to:
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Note Use the show cable spectrum-group command to display the current allocation table and frequency assignments. |
Following is a sample topology for a Cisco uBR7223 with combiner groups designated A through J. Combiner groups C and E have multiple upstream ports. These should be configured in a shared spectrum group. The other upstreams should be configured in a non-shared spectrum group.
In this example, ten combiner groups are served with frequency hop tables from three spectrum groups:
Cable3/0 DS +-----+ Upconverter +----- laser group 1 U0 +----- combiner group A U1 +----- combiner group B U2 +------combiner group C U3 +------combiner group C U4 +----- combiner group D U5 +------combiner group E Cable4/0 DS +-----+ Upconverter +----- laser group 2 U0 +------combiner group E U1 +----- combiner group F U2 +----- combiner group G U3 +----- combiner group H U4 +----- combiner group I U5 +----- combiner group J
The laser group term refers to the set of fiber nodes that share the same downstream signal. An optical splitter is often used to create individual feeds-per-node.
In the downstream direction, two 6 MHz channel slots are assigned. All fiber nodes in combiner groups A-E should have a channel slot containing the downstream signal from Cable3/0. Combiner groups A-E are said to belong to "laser group 1."
All fiber nodes in combiner groups E-J should have a channel slot containing the downstream signal from Cable4/0. Combiner groups E-J are said to belong to "laser group 2."
Because combiner group E belongs to two laser groups, there should be two different downstream channel slots for Cable3/0 and Cable4/0.
Assuming that all combiner groups use the frequency band from 20-26 MHz, the following configuration enables spectrum management for all upstream ports:
cable spectrum-group 1 band 20000000 26000000 cable spectrum-group 2 shared cable spectrum-group 2 band 20000000 26000000 cable spectrum-group 3 shared cable spectrum-group 3 band 20000000 26000000 interface Cable3/0 cable spectrum-group 1 cable upstream 2 spectrum-group 2 cable upstream 3 spectrum-group 2 cable upstream 5 spectrum-group 3 interface Cable4/0 cable spectrum-group 1 cable upstream 0 spectrum-group 3
A description of the spectrum groups 1 through 3 follows:
Upstream Port RF Domain Cable3/0 U0 combiner group A Cable3/0 U1 combiner group B Cable3/0 U4 combiner group D Cable4/0 U1 combiner group F Cable4/0 U2 combiner group G Cable4/0 U3 combiner group H Cable4/0 U4 combiner group I Cable4/0 U5 combiner group J
Upstream Port RF Domain Cable3/0 U2 combiner group C Cable3/0 U3 combiner group C
Upstream Port RF Domain Cable3/0 U5 combiner group E Cable4/0 U0 combiner group E
For the 20-26 MHz band of each RF domain, the spectrum is channelized according to the channel width settings of each member port. For example, if the ports U2 and U3 of Cable3/0 are set to 3.2 MHz and 1.6 MHz channel widths, respectively, then spectrum group 2 uses the following channelization:
> Channel Width Start Stop Center > (Mhz) (Mhz) (Mhz) (Mhz) > 1 3.2 20.0 23.2 21.6 > 2* 1.6 20.0 21.6 20.8 > 3* 1.6 21.6 23.2 22.4 > 4 1.6 23.2 24.8 24.0
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Note Channels 2 and 3 are not available when channel 1 is in use. |
Because the group is shared, ports U2 and U3 will be assigned channels 1 and 4, respectively, to prevent overlap.
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Note No alternate frequency assignments exist for either port. Bandwidth is wasted from 24.8-to-26.0 MHz. To create alternate channels, increase the upper boundary from 26.0-to-28.0 MHz. |
> Channel Width Start Stop Center > (Mhz) (Mhz) (Mhz) (Mhz) > 1 3.2 20.0 23.2 21.6 > 2 3.2 23.2 26.4 24.8 > 3 1.6 20.0 21.6 20.8 > 4 1.6 21.6 23.2 22.4 > 5 1.6 23.2 24.8 24.0 > 6 1.6 24.8 26.4 25.6 > 7 1.6 26.4 28.0 27.4
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Tips Take care to reduce the spectrum allocation when using with small channel widths. Otherwise, there will be a large number of upstream channel slots. For example, if the allocation is from 20.0 to 28.0 MHz and an upstream port has its channel width set to 0.2 MHz, then there will be 40 possible slots for that channel width. Blind frequency hopping can require quite a long time to find the clean slot since it will try each available slot, one at a time for several seconds each try. |
In addition to frequency, the nominal input power level of the upstream receivers can be set at the time of frequency hop. This allows the cable operator to perform minor equalization as a function of frequency.
cable spectrum-group 1 frequency 21600000 cable spectrum-group 1 frequency 24800000 1 cable spectrum-group 1 frequency 28000000 2
In this example, the upstream port nominal receive power at 21.6 MHz is 0 dBmV, at 24.8 MHz is 1 dBmV, and at 28.0 MHz is 2 dBmV. At any time, the power level set in the interface configuration overrides the spectrum group power level.
You can add spectrum on a weekly schedule by including an optional weekday and time:
cable spectrum-group 1 time Mon 08:00:00 frequency 21600000
Deletion is performed using the "delete" keyword:
cable spectrum-group 1 time Mon 18:00:00 delete frequency 21600000
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Tips If your cable plant has an upstream noise characteristic on a weekly cycle, use time-scheduled spectrum allocation. |
Per DOCSIS RFI specification section 6.3.2.2, RF channel migration occurs by broadcasting a change in the UCD message to all cable modems. The UCD message contains the upstream frequency and transmission parameters associated with an upstream channel.
The speed of channel migration using the UCD message is typically less than 20 ms. During that time, upstream transmission is interrupted until the cable modem transmitter adjusts to its new frequency. Data is stored in the cable modem's buffers for this brief time and sent when the frequency hop is complete.
Also, per the DOCSIS RFI, station maintenance intervals are used to perform per-modem keepalive polling. The Cisco CMTS poll each cable modem at a default rate of once every 10 seconds.
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Tips Using Cisco IOS Release 12.0(7)XR2 or Cisco IOS Release 12.1(1a)T1, you can set polling options to obtain parameter and status information on an ongoing basis. You can adjust default rates. Refer to the "Polling Cable Modems" section. |
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Note When ingress noise causes loss of keep alive messages from a configurable percentage of all cable modems connected to an MC16S that is operating with Cisco IOS Release 12.0(7)XR2, Cisco IOS Release 12.1(1a)T1 or higher, a new frequency is selected from the allocation table and an UCD update is performed. |
The migration time is 10 seconds (maximum) for the decision and 20 ms for the frequency hop. The system will not hop endlessly, because one cable modem is generating 90% of the errors and 90% of the traffic.
The default threshold of 100% can be modified using the following Cisco IOS global configuration command:
cable spectrum-group {1|2|3|...|32} frequency hop threshold {1|2|3|...|100}
The percentage threshold method prevents a single failing cable modem from affecting service to other good cable modems. To prevent excessive frequency hop, the minimum period between hops can be changed from the default value of 300 seconds using the following Cisco IOS global configuration command:
cable spectrum-group {1|2|3|...|32} frequency hop period {1|2|3|...|3600}
If the destination channel is expected to be impaired, then the frequency hop period threshold can be reduced to a small value such as 10 seconds. This allows the frequency hop to continue more rapidly until a clear channel is found.
The commands described here configure and display physical layer (PHY) parameters.
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Note The downstream port is separate from its associated upstream ports. |
The downstream port is shut down whenever the interface is administratively shutdown. Although shut down, the downstream continues to output either a 64 QAM or 256 QAM carrier at an intermediate frequency (IF) centered at 44 MHz for C versions of cable modem cards and the MC16S. The MC16E transmits downstream IF signals to an upconverter at a frequency of 36.125MHz.
The downstream carrier must be DOCSIS or EuroDOCSIS-compliant with a bandwidth of 6 or 8 MHz and an MPEG framing format that complies with either ITU-T J.83 Annex B or Annex A based on the cable modem card used. The default state is "shutdown."
The IF output must be passed through an upconverter to place it in an assigned cable television channel at a fixed frequency center between 54 and 1,020 MHz. Because the upstream parameters must be configured by the operator, the upstream ports have a default state of "shutdown."
The upstream port becomes "up" when it is assigned an upstream frequency and it is configured to be administratively up. Configuring a spectrum group enables frequency agility and disables the fixed upstream frequency setting.
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Note Frequency assignment is independent of the configured shutdown state. A configured no cable upstream n shutdown places the port in the "adminup" state. If cable upstream n shutdown is configured and no frequency assigned, then the port transitions to the "down" state. |
Configuring a spectrum group allows the upstream frequency and input power level to change whenever noise impairs upstream data traffic.
cable spectrum-group groupnum [ time day hh:mm:ss ] [delete] frequency ctr-freq-hz power-level-dBmV cable spectrum-group groupnum [ time day hh:mm:ss ] [delete] band start-freq-hz end-freq-hz power-level-dBmV
The groupnum value specifies the spectrum group number; valid range is 1 to 32. If the time parameter is present, then the frequency setting or band is made available or deleted at the specified time. The delete option specifies that the frequency setting or band should be removed from use at the specified time. The frequency value specifies that a center frequency setting should be a unit of allocated spectrum in this spectrum group.
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Note A channel width of 3.2 MHz is assumed for allocation purposes. For example, if center frequency is configured as 20.0 MHz, then the band 18.4-21; 6 MHz will be added to the allocated spectrum. This applies even if the configured channel width is smaller. |
The ctr-freq-hz value specifies the upstream center frequency; valid range is 5,000,000 to 42,000,000 Hz (5 to 42 MHz) for all cable modem cards except the MC16E. For the MC16E, valid range is 5,000,000 to 65,000,000 Hz (5 to 65 MHz). Half of the upstream carrier energy is distributed below and the other half above this point.
The band value designates a continuous band setting should be the unit of allocated spectrum in this spectrum group.
The start-freq-hz value specifies the lower boundary of a frequency band. The end-freq-hz specifies the upper boundary of a frequency band. The power-level-dBmV specifies the nominal input power level; the valid range is -10 to +25 dBmV.
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Note You might wish to change only the input power level and not frequency on a daily time schedule based on your cable plant characteristics. |
The no cable spectrum-group groupnum specifies that a given spectrum group be deleted.
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Note Member upstream ports may transition to the "down" state because there is no spectrum to assign. Reconfigure more bands or move the upstream ports to another spectrum group to bring them back up. |
The [no] cable spectrum-group n shared option indicates that upstream ports must share the same spectrum, and therefore, must never be set for overlapping carriers.
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Note By default, the upstream can overlap for all ports in the same spectrum group if this option is not configured. |
The [no] cable spectrum-group n hop period period-sec and [no] cable spectrum-group n hop threshold thres-pcnt hop designates that a frequency hop parameter be configured for a period of time. The period-sec value indicates the maximum frequency rate to be configured; valid range is 1 to 3600 seconds. This parameter limits the frequency hop rate to a configured period value in seconds.
The configured value can be returned to its default of 300 seconds using the no keyword for thres-pcnt; valid range is 0 to 100 percent.
Specify upstream channel width in Hz. Valid values are 200000, 400000, 800000, 1600000, and 3200000 based on the cable modem card used. The corresponding symbol rate is 160000, 320000, 640000, 1280000, and 2560000 symbols/sec. A default value of 1600000 Hz (1280000 symbols/sec) is configured by the no keyword.
cable upstream n channel-width width [no] cable upstream n channel-width width
The channel width set by this command determines the amount of spectrum needed during frequency assignment.
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Note This command is not valid with early MC11 cable modem cards. |
The [no] cable upstream port shutdown and shutdown (Default) disables the upstream port. In this mode, downstream UCD and MAP messages for the upstream channel are disabled. This inhibits the upstream transmitters on the cable modems.
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Note Shutting down the interface does not prevent frequency assignment. |
The no...shutdown enables the upstream port. Configure this option to enable data traffic.
The following commands:
no cable spectrum-group groupnum
Enable frequency agility and spectrum management for upstream frequency and power. The global spectrum group specified by groupnum defines the frequency table; otherwise, the upstream port will assume the "down" state.
The AutoInstall process is designed to configure the Cisco CMTS automatically after connection to your WAN. For AutoInstall to work properly, a Transmission Control Protocol/Internet Protocol (TCP/IP) host on your network must be preconfigured to provide the required configuration files. The TCP/IP host can exist anywhere on the network as long as the following two conditions are maintained:
This functionality is coordinated by your system administrator at the site where the TCP/IP host is located. You should not use AutoInstall unless the required files are available on the TCP/IP host. See the publications Configuration Fundamentals Configuration Guide and Configuration Fundamentals Command Reference for information about how AutoInstall works.
Complete the following steps to prepare your Cisco CMTS for the AutoInstall process:
Step 2 Turn the power switch on each power supply to the ON (|) position. This action turns on power to the router.
The router loads the operating system image from Flash memory; this process can take several minutes. If the remote end of the WAN connection is connected and properly configured, the AutoInstall process begins.
Step 3 When the AutoInstall process is completed, use the copy running-config startup-config command to write the configuration data to the router's nonvolatile random-access memory (NVRAM):
Router# copy running-config startup-config
Completing this step saves the configuration settings that the AutoInstall process created to NVRAM. If you fail to do this, your configuration will be lost the next time you reload the router.
If you do not plan to use AutoInstall, do not connect the router's WAN or LAN cable to the channel service unit/data service unit (CSU/DSU). If the WAN or LAN cable is connected to the CSU/DSU and the router does not have a configuration stored in NVRAM, the router attempts to run AutoInstall at startup.
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Tips The router might take several minutes to determine that AutoInstall is not set up to a remote TCP/IP host. |
When the router determines that AutoInstall is not configured, it defaults to the setup facility (also called the System Configuration dialog). If the LAN or WAN cable is not connected, the router boots from Flash memory and automatically executes the setup facility.
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Note You can run the setup facility any time you are at the enable prompt (#) by entering the setup command. |
When you first start the program, configure the global parameters to control system-wide settings:
Step 2 After booting from Flash memory, the following information appears after about 30 seconds. When you see this information, you have successfully booted your router:
Restricted Rights Legend
Use, duplication, or disclosure by the Government is
subject to restrictions as set forth in subparagraph
(c) of the Commercial Computer Software - Restricted
Rights clause at FAR sec. 52.227-19 and subparagraph
(c) (1) (ii) of the Rights in Technical Data and Computer
Software clause at DFARS sec. 252.227-7013.
cisco Systems, Inc.
170 West Tasman Drive
San Jose, California 95134-1706
Cisco Internetwork Operating System Software
IOS (tm) uBR7200 Software (uBR7200-I-M), Version 11.3(6)NA [kpfjrgiu 100]
Copyright (c) 1986-1998 by cisco Systems, Inc.
Compiled Mon 09-Oct-98 04:10 by smith
cisco 7200 (R4700) processor with 22528K/10240K bytes of memory.
R4700 processor, Implementation 33, Revision 1.0 (Level 2 Cache)
Last reset from power-on
Bridging software.
SuperLAT software copyright 1990 by Meridian Technology Corp). X.25 software, Version 2.0, NET2, BFE and GOSIP compliant. TN3270 Emulation software (copyright 1994 by TGV Inc). 4 Ethernet/IEEE 802.3 interfaces. 5 FastEthernet/IEEE 802.3 interfaces. 8 Serial network interfaces. 125K bytes of non-volatile configuration memory. 20480K bytes of Flash PCMCIA card at slot 0 (Sector size 128K). 4096K bytes of Flash internal SIMM (Sector size 256K). Configuration register is 0x0
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Note The first two sections of the configuration script —the banner and the installed hardware—appear only at initial system startup. On subsequent uses of the setup command facility, the script begins with the following prompt. |
--- System Configuration Dialog ---At any point you may enter a questions mark `?' for help.Use ctrl-c to abort configuration dialog at any prompt.Default settings are in square brackets `[]'.continue with configuration dialog? [yes/no]:
Step 3 When asked if you want to enter the System Configuration dialog and see the current interface summary, enter yes or press Return:
Continue with configuration dialog? [yes/no]: First, would you like to see the current interface summary? [yes]:
In the following example, the summary shows a Cisco CMTS at first-time startup with nothing configured:
Any interface listed with OK? value "NO" does not have a valid configuration. Interface IP-Address OK Method Status Protocol Ethernet1/0 9.2.22.3 YES NVRAM up up Ethernet1/1 unassigned YES unset administratively down down Ethernet1/2 unassigned YES unset administratively down down Ethernet1/3 unassigned YES unset administratively down down Ethernet1/4 unassigned YES unset administratively down down Ethernet1/5 unassigned YES unset administratively down down Ethernet1/6 unassigned YES unset administratively down down Ethernet1/7 unassigned YES unset administratively down down
Step 4 Choose which protocols to support on your interfaces. For IP-only installations, you can accept the default values for most of the questions. A typical configuration using IP follows and continues through Step 7:
Configuring global parameters: Enter host name [Router]: router
Step 5 Enter the enable secret password, the enable password, and the virtual terminal password:
The enable secret password is a one-way cryptographic secret
password used instead of the enable password when it exists. Enter enable secret: ****** The enable password is used when there is no enable secret
password and when using older software and some boot images. Enter enable password: ****** Enter virtual terminal password: ******
Enter yes to accept SNMP management; enter no to refuse it:
Configure SNMP Network Management? [no]:
Community string [public]:
Step 7 In all cases, you will use IP routing. When you are using IP routing, select an interior routing protocol. You can specify only one of two interior routing protocols to operate on your system using setup: Interior Gateway Routing Protocol (IGRP) or Routing Information Protocol (RIP).
To configure IP routing, enter yes (the default) or press Return, and then select an interior routing protocol:
Configure IP? [yes]:
Configure IGRP routing? [yes]:
Your IGRP autonomous system number [1]: 15
Step 8 Configure your port adapter interface parameters. In this example, an 8-port Ethernet port adapter is installed in port adapter slot 1. The setup program will determine the status of all interfaces.
To configure each active interface port for IP, enter yes (the default) or press Return. For all inactive ports, the default will be no. You can press Return to accept the default.
Configuring interface Ethernet1/0:
Is this interface in use? [yes]:
Configure IP on this interface? [yes]:
IP address for this interface [19.2.22.4]:
Number of bits in subnet field [8]:
Class A network is 19.0.0.0, 8 subnet bits; mask is /16
Configuring interface Ethernet1/1:
Is this interface in use? [no]:
Configuring interface Ethernet1/2:
Is this interface in use? [no]:
Configuring interface Ethernet1/3:
Is this interface in use? [no]:
Configuring interface Ethernet1/4:
Is this interface in use? [no]:
Configuring interface Ethernet1/5:
Is this interface in use? [no]:
Configuring interface Ethernet1/6:
Is this interface in use? [no]:
Configuring interface Ethernet1/7:
Is this interface in use? [no]:
Step 9 Configure your cable modem card interface parameters. In this example, an MC11C cable modem card is installed in cable modem card slot 3 of a Cisco uBR7246. The setup program will, for the most part, determine the status of all interfaces.
To configure each active interface port, enter yes (the default) or press Return. For all inactive ports, the default will be no. You can press Return to accept the default.
Configuring interface cable 3/0: Is this interface in use? [yes]: Configure this interface? [yes]: IP address for this interface [19.2.22.5]: Number of bits in subnet field [8]: Class A network is 19.0.0.0, 8 subnet bits; mask is /16 Configuring interface cable 3/1: Is this interface in use? [yes]: Configure this interface? [yes]: IP address for this interface [19.2.22.6]: Number of bits in subnet field [8]: Class A network is 19.0.0.0, 8 subnet bits; mask is /16
The configuration program displays the command interface script just created:
The following command script was created: hostname router enable secret 5 $1$f0fc$A38P/KN/9yD3sEKSt6hKQ/ enable password betty line vty 0 4 password wilma snmp-server community public ! ip routing ! interface Ethernet1/0 ip address 19.2.22.4 255.255.0.0 ! interface Ethernet1/1 shutdown no ip address ! interface Ethernet1/2 shutdown no ip address ! interface Ethernet1/3 shutdown no ip address ! interface Ethernet1/4 shutdown no ip address ! interface Ethernet1/5 shutdown no ip address ! interface Ethernet1/6 shutdown no ip address ! interface Ethernet1/7 shutdown no ip address !
interface cable 3/0 ip address 19.2.22.5 255.255.0.0 interface cable 3/1 ip address 19.2.22.6 255.255.0.0 router igrp 15 network 19.0.0.0 ! end
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Note You must configure upstream channel frequencies and profiles using the command interface in Cisco IOS Release 12.0(5)T1 or higher. The setup facility currently does not support configuring upstream parameters. See the next section, "Configuring Upstream Frequencies." |
Step 10 When asked if you want to use this configuration, enter yes or press Return.
Use this configuration? [yes/no]: yes
Step 11 Save your settings to NVRAM. (Refer to the "Using the Setup Facility for Cable Interfaces" section.)
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Note You must always manually save the configuration settings to NVRAM whenever they are modified. |
Upstream parameters must be configured manually. After the setup facility is run, upstream ports have a default state of "shutdown." To configure upstream channel frequencies, you have two choices:
The cable modem card receiver accepts time-division multiplexed burst transmissions from cable modems (or cable modems in set top boxes) which are DOCSIS- or EuroDOCSIS-based. The upstream port becomes "up" when it is assigned an upstream frequency and is configured to be administratively up.
The upstream port is frequency-agile. The frequency can change while the interface is up and carrying traffic, if you define spectrum groups per the example provided.
You can define individual modulation profiles. A modulation profile consists of a table of physical layer characteristics for the different types of upstream bursts, for example, initial maintenance, long grant, request/data, request, short grant, and station maintenance.
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Note If you are using the first version of the MC11 cable modem card, you cannot define an alternative upstream modulation profile. |
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Note Only qualified personnel should define upstream modulation profiles. |
To activate upstream interfaces:
Step 2 Enter the configure terminal command to get into global configuration mode.
Step 3 In global configuration mode, configure modulation profiles and/or spectrum groups for your Cisco CMTS using the cable modulation-profile and cable spectrum-group commands.
Step 4 To configure individual upstream interfaces on the MC16S, enter the cable upstream interface number command to get into cable interface configuration mode.
Step 5 While in cable interface configuration mode, configure various characteristics for the interface in question using the cable upstream commands.
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Note Refer to "Understanding System Operations" for further information. |
Follow the procedure in this section to configure WAN or LAN interfaces. To configure interface parameters, have your interface network addresses and subnet mask information ready.
Configuring interface parameters: Configuring interface Ethernet0/0: Is this interface in use? [no]: yes Configure IP on this interface? [no]: yes IP address for this interface: 1.1.1.10 Number of bits in subnet field [0]: Class A network is 1.0.0.0, 0 subnet bits; mask is 255.0.0.0
Step 2 Do not enable Internetwork Package Exchange (IPX) on this interface; IPX is not supported on the Cisco CMTS:
Configure IPX on this interface? [no]: no
Step 3 If additional Ethernet interfaces are available in your system, enter their configurations when you are prompted.
Step 4 Save your settings to NVRAM. (See the "Using the Setup Facility for Cable Interfaces" section.)
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Note You must always manually save the configuration settings to NVRAM whenever they are modified. |
Configuring interface Serial0/0: Is this interface in use? [no]: yes
Step 2 Determine which protocols you want on the synchronous serial interface and enter the appropriate responses:
Configure IP unnumbered on this interface? [no]: IP address for this interface: 10.1.1.20 Number of bits in subnet field [0]: Class A network is 10.0.0.0, 0 subnet bits; mask is 255.0.0.0
Step 3 If additional synchronous serial interfaces are available in your system, enter their configurations when you are prompted.
Step 4 Save your settings to NVRAM. (See the "Using the Setup Facility for Cable Interfaces" section.)
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Note You must always manually save the configuration settings to NVRAM whenever they are modified. |
The following sample display includes a continuous listing of all interface configuration parameters selected for Ethernet and synchronous serial interfaces. These parameters are shown in the order in which they appear on your console terminal.
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Tips Only one Ethernet and one synchronous serial interface are configured for this example. |
Configuring interface parameters: Configuring interface Ethernet0/0: Is this interface in use? [no]: yes Configure IP on this interface? [no]: yes IP address for this interface: 10.1.1.10 Number of bits in subnet field [0]: Class A network is 10.0.0.0, 0 subnet bits; mask is 255.0.0.0 Configure IPX on this interface? [no]: Configure AppleTalk on this interface? [no]: no Configuring interface Serial0/0: Is this interface in use? [no]: yes Configure IP on this interface? [no]: yes Configure IP unnumbered on this interface? [no]: IP address for this interface: 10.1.1.20 Number of bits in subnet field [0]: Class A network is 10.0.0.0, 0 subnet bits; mask is 255.0.0.0 Configure IPX on this interface? [no]: Configure AppleTalk on this interface? [no]: The following configuration command script was created: hostname Router enable secret 5 $1$u8z3$PMYY8em./8sszhzk78p/Y0 enable password wilma line vty 0 4 password s snmp-server community public ! ip routing no vines routing no ipx routing no appletalk routing no apollo routing no decnet routing no xns routing no clns routing no bridge 1
! Turn off IPX to prevent network conflicts. interface Ethernet0/0 no ipx network interface Ethernet0/1 no ipx network ! interface Ethernet0/0 ip address 1.1.1.10 255.0.0.0 no mop enabled ! interface serial0/0 ip address 1.1.1.20 255.0.0.0 ip route-cache cbus no keepalive ! ! router igrp 15 network 1.0.0.0 ! end Use this configuration? [yes/no]: yes [OK] Use the enabled mode `configure' command to modify this configuration. Press RETURN to get started!
Your Cisco CMTS is now minimally configured and is ready to use. You can use the setup command if you want to modify the parameters after the initial configuration. To perform more complex configurations, use the configure command.
Step 2 When asked if you want to enter the initial dialog, answer no to go into the normal operating mode of the router:
Would you like to enter the initial dialog? [yes]: no
Step 3 After a few seconds, the user EXEC prompt (Router>) is displayed. Type enable to enter enable mode (configuration changes can only be made in enable mode):
Router> enable
The prompt changes to the enable modem (also called privileged EXEC) prompt:
Router#
Step 4 Enter the configure terminal command at the enable prompt to enter configuration mode from the terminal:
Router# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)#
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Tips To see a list of the configuration commands available to you, enter ? at the prompt or type help while in configuration mode. |
Step 5 At the Router(config)# prompt, enter the interface type slot/port command to enter the interface configuration mode:
Router(config)#interface cable slot/portRouter(config-if)#
Step 6 Set the downstream center frequency to reflect the digital carrier frequency of the downstream RF carrier (the channel) for the downstream port:
Router (config-int) # cable downstream frequency down-freq-hz
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Note This command has no effect on the external upconverter. It is informational only. |
Step 7 Activate the downstream port on the cable modem card to support digital data transmission over the HFC network:
Router (config-int) # no shutdown
Step 8 Enter the fixed center frequency for your downstream RF carrier in Hz and the port number:
Router (config-int) # cable upstream port frequency up-freq-hz
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Note Be sure not to select an upstream frequency that interferes with that used for any other upstream application in your cable plant. |
Step 9 Repeat step 8 for each upstream port on the cable modem card.
Step 10 Activate the upstream port:
Router (config-int) # no cable upstream port shutdown
Step 11 Repeat step 10 to activate each port used on your cable modem card.
Step 12 Exit to return to the configuration mode:
Router (config-if) # exit
Router (config) #
Step 13 Enter the next interface to configure, following steps 6 through 12, or exit to return to the enable mode.
Router (config) # exit
Router# %SYS-5-CONFIG_I: Configured from console by console#
Step 14 Save the configuration to NVRAM:
Router# copy running-config startup-config
The setup utility creates an initial configuration. The basic management setup configures only enough connectivity for management of the system, the extended setup will prompt you to configure each interface on the system
To invoke the configuration facility, use the following command:
ishita-cmts#setup
The following is the system configuration dialog:
Continue with configuration dialog? [yes/no]: yes
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Tips At any time you can enter a question mark (?) for help. Use ctrl-c to abort the configuration dialog at any prompt. The default settings are enclosed in brackets '[]'. |
Would you like to enter basic management setup? [yes/no]: no First, would you like to see the current interface summary? [yes]: Interface IP-Address OK? Method Status Protocol FastEthernet0/0 10.20.133.2 YES NVRAM up up Ethernet1/0 1.11.1.1 YES NVRAM up up Ethernet1/1 unassigned YES NVRAM administratively down down Ethernet1/2 unassigned YES NVRAM administratively down down Ethernet1/3 unassigned YES NVRAM administratively down down Cable5/0 10.20.133.65 YES NVRAM up up
Enter host name [ishita-cmts]:
The enable secret is a password used to protect access to privileged EXEC and configuration modes. This password, after entered, becomes encrypted in the configuration.
Enter enable secret [<Use current secret>]: aa
The enable password is used when you do not specify an enable secret password, with some older software versions, and some boot images.
Enter enable password [rHoz]: bb
The virtual terminal password is used to protect access to the router over a network interface.
Enter virtual terminal password [cc]:cc
Configure SNMP Network Management? [no]: Configure IP? [yes]: Configure IGRP routing? [yes]: Your IGRP autonomous system number [1]: Configure CLNS? [no]: Configuring interface parameters: Do you want to configure FastEthernet0/0 interface? [yes]: Use the 100 Base-TX (RJ-45) connector? [yes]: Operate in full-duplex mode? [no]: Configure IP on this interface? [yes]: no Do you want to configure Ethernet1/0 interface? [yes]: n Do you want to configure Ethernet1/1 interface? [no]: n Do you want to configure Ethernet1/2 interface? [no]: n Do you want to configure Ethernet1/3 interface? [no]: n Do you want to configure Cable5/0 interface? [yes]: Downstream setting frequency : 531000000 For cable upstream [0] Shut down this upstream ? [yes/no]: no Frequency : 33808000 Would you like to configure the DHCP server ? [yes/no]: yes IP address for the DHCP server [X.X.X.X]: 10.0.0.2 Configure IP on this interface? [no]: yes IP address for this interface: 10.20.133.65 Subnet mask for this interface [255.0.0.0] : 255.255.255.248 Class A network is 10.0.0.0, 29 subnet bits; mask is /29
The following configuration command script was created:
interface Cable5/0 ip address 10.20.133.65 255.255.255.248 no ip mroute-cache no keepalive cable insertion-interval 500 cable downstream annex B cable downstream modulation 64qam cable downstream interleave-depth 32 cable downstream frequency 531000000 cable upstream 0 frequency 33808000 cable upstream 0 power-level 0 no cable upstream 0 shutdown cable helper-address 10.0.0.2
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Note For modems to acquire an IP address, they must have direct access to DHCP / TFTP/ TOD servers or have a static route set. |
To store the configuration or changes to your startup configuration in NVRAM, enter the copy running-config startup-config command at the Router# prompt:
Router# copy running-config startup-config
This command saves the configuration settings you set using configuration mode, the setup facility, or AutoInstall.
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Tips If you do not save your settings, your configuration will be lost the next time you reload the router. |
You can check your settings and review any changes to your configuration using various software commands.
To view information specific to the hardware and cable interface configuration on your Cisco CMTS, use show commands.
To verify the downstream center frequency:
Router# show controllers cable slot/port downstream
To verify the current value of an upstream port frequency:
Router# show controllers cable slot/port upstream
To check the value of the settings you entered, enter the show running-config command at the Router# prompt:
Router# show running-config
To review changes you make to the configuration, use the EXEC show startup-config command to display the information stored in NVRAM.
This section supplements the Cisco Network Registrar (CNR) documentation. The section provides additional cable-specific instructions pertinent to the Cisco CMTS and CMTS management.
CNR is a dynamic IP address management system, currently running on Windows NT or Solaris 2.6, that uses the Dynamic Host Configuration Protocol (DHCP) to assign IP addresses to cable modems, PCs, and other devices on the broadband network. The CNR tool includes script extensions that allow a cable system administrator to define and view individual DHCP options, define the identity or type of device on the network, and assign the device to a predefined class or group.
Using the CNR tool, a cable system administrator can specify policies to provide:
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Note This is available only in CNR 3.0 or higher. |
Using the CNR tool and the extension scripts identified in the "Scripts" section, a cable system administrator can specify scopes, policies, and options for the network and each cable modem based on the services and configuration to support at each subscriber site.
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Note Scopes refer to the administrative grouping of TCP/IP addresses; all IP addresses within a scope should be on the same subnet. |
The cable system administrator defines system default policies for all standard options and uses scope-specific policies for options related to particular subnets, such as cable modems. This allows DHCP to send the information with the IP address.
Seven entry points exist for scripts:
Each cable modem on the broadband network requires the following fields in the DHCP response:
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Note For cable operators with less experience in networking, you can fill in a guess based on the network number and indicate how your IP network is divided. |
DOCSIS DHCP option requirements include:
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Note If the DHCP server is on a different network that uses a relay agent, then the relay agent must set the gateway address field of the DHCP response. |
DOCSIS Option82 modifies DHCPDISCOVER packets to distinguish cable modems from the CPE devices or "clients" behind them. The DOCSIS Option82 is comprised of the following two suboptions:
Type 1 (1 byte) Len 4 (1 byte) Value (8 bytes) <bit 31,30,....................0) <xYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY>
x=1 Cable Modem REQx=0 CPE device
(Behind the cable modem with the cable modem MAC address shown in suboption 2.) Y=0xYYYYYYY is the SNMP index to the CMTS interface.Type 2 (1 byte) Len 6 (1 byte) Value xxxx.xxxx.xxxx (6 bytes)
This section lists the scripts applicable to cable modem configuration.
To support two-way configurations at a subscriber site, use these scripts:
To support telco return and two-way cable modem configurations on the same cable modem card or chassis, use these scripts:
For CNR running on Windows NT, place the appropriate scripts in the following directory:
\program files\network registrar\extensions\dhcp\scripts\tcl
For CNR running on Solaris, place the appropriate scripts in the following directory:
/opt/nwreg2/extensions/dhcp/scripts/tcl
To activate the scripts after you have placed them in the appropriate directory:
Step 2 Open one of the scripts at the nrcmd> command prompt.
Step 3 Create the extension points and attach them to the system.
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Note The easiest way to do this is to simply cut and paste the command lines from the scripts to the nrcmd> command line. |
Step 4 After you have created and attached the extension points, do a dhcp reload.
The scripts are active.
Each cable interface must be set up as a BOOTP forwarder and have the relay-option enabled. The primary and secondary IP addresses for each cable interface must be in sync with the CNR tool.
To properly communicate with scripts in the system, implement the following commands on the Cisco CMTS:
cable relay-agent-option
ip dhcp relay info option
no ip dhcp relay information option check
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Note You can also use the cable dhcp-giaddr command in cable interface configuration mode to modify the GIADDR field of DHCPDISCOVER and DHCPREQUEST packets to provide a relay IP address before packets are forwarded to the DHCP server. Use this command to set a "policy" option such that primary addresses are used for cable modems and secondary addresses are used for hosts behind the cable modems. |
Add these options to the system default policy for:
Define these settings following the CNR tool documentation:
Define these settings following the CNR tool documentation:
When you create your scope selection tags:
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Note These names have to be exactly as they appear in the scripts. |
Step 2 Then attach the selection tags to the appropriate scripts:
Example:
CM_Scope tagCablemodem
PC_Scope tagComputer
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Note If you are using the prepacketencode and postclientlookup .tcl scripts for telco return, the telco return scope does not have a selection tag associated to the scope. |
Step 2 Follow the same procedure as above, but use a telco return policy which has a different .cm file with telco-specific commands in it.
Following is an example for creating scopes for your network. This example assumes there are two Cisco CMTSs in two locations, with one cable modem card on one Cisco CMTS configured for telco return.
cm-toledo1_2-0 10.2.0.0 255.255.0.0 assignable 10.2.0.10-10.2.254.254 tagCablemodem tagTelcomodem Default GW=10.2.0.1 (assigned by scripts) cm-toledo1_3-0 10.3.0.0 255.255.0.0 assignable 10.3.0.10-10.3.254.254 tagCablemodem tagTelcomodem Default GW=10.3.0.1 (assigned by scripts) pc-toledo1_2-0 208.16.182.0 255.255.255.248 assignable 208.16.182.2-208.16.182.6 tagComputer Default GW=208.16.182.1 (assigned by scripts) pc-toledo1_3-0 208.16.182.8 255.255.255.248 assignable 208.16.182.10-208.16.182.14 tagComputer Default GW=208.16.182.9 (assigned by scripts) telco_return_2-0 192.168.1.0 255.255.255.0 (No assignable addresses, tag was put on cable modem primary scope to force telco-return cable modem to pull address from primary scope) cm-arlington1_2-0 10.4.0.0 255.255.0.0 assignable 10.4.0.10-10.4.254.254 tagCablemodem Default GW=10.4.0.1 (assigned by scripts) cm-arlington1_3-0 10.5.0.0 255.255.0.0 assignable 10.5.0.10-10.5.254.254 tagCablemodem Default GW=10.5.0.1 (assigned by scripts) pc-arlington1_2-0 208.16.182.16 255.255.255.248 assignable 208.16.182.17-208.16.182.22 tagComputer Default GW=208.16.182.17 (assigned by scripts) pc-toledo1_3-0 208.16.182.24 255.255.255.248 assignable 208.16.182.2-208.16.182.30 tagComputer Default GW=208.16.182.25 (assigned by scripts)
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Note Remember the last valid address in the .248 subnet range is the broadcast address; do not use this. |
To support Class of Service (CoS), define:
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Note This is needed for Option82. |
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Note Scope selection tags are excluded from or included in client-classes. |
To assign the CoS or use Option82, make a client entry with a MAC address and point to the appropriate policy. To use client-based MAC provisioning, add a client entry "default - exclude," then put in MAC addresses for all devices (for example, cable modems and PCs) in the client tab and select the policy to use, including the appropriate tag.
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Note For more detailed information about Cisco Network Registrar, please refer to the document Cisco Network Registrar for the Cisco uBR7200 Series Universal Broadband Routers. |
The CNR configuration is done differently if subinterfaces are configured. Here is an example. If you have configured two ISP subinterfaces and one management subinterface on a Cisco uBR7200 series, ensure that the management subinterface is the first subinterface that is configured. If cable interface three—c3/0—is being used, create c3/0.1, c3/0.2 and c3/0.3 as three subinterfaces and c3/0.1 as the first subinterface configured as the management subinterface.
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Note The Cisco uBR7200 series requires management subinterfaces to route DHCP packets from CMs when they first initialize because the Cisco uBR7200 series does not know the subinterfaces they belong to until it has seen the IP addresses assigned to them by gleaning DHCP reply message from CNR. |
In CNR, complete the following steps for such a configuration:
Step 2 Configure three scopes; for example, mgmt-scope, isp1-cm-scope, and isp2-cm-scope such that isp1-cm-scope and isp2-cm-scope each define mgmt-scope to be the primary scope
Step 3 Also configure two scopes for PCs for each of the ISPs; isp1-pc-scope and isp2-pc-scope. For scope isp1-cm-scope, configure isp1-cm-tag to be the scope selection tag. For scope isp2-cm-scope, configure isp2-cm-tag to be the scope selection tag
Step 4 Configure two client classes; for example, isp1-client-class and isp2-client-class
Step 5 Create client entries with their MAC addresses for CMs that belong to ISP1 and assign them to isp1-client-class. Also assign the scope selection tag isp1-cm-tag
Step 6 Create client entries for CMs that belong to ISP2 and assign them to isp2-client-class. Also assign the scope selection tag isp2-cm-tag
Step 7 Enable client class processing from the scope-selection-tag window
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Note Overlapping address ranges cannot be configured on these subinterfaces because software gleans the DHCP reply to figure out the subinterface it really belongs to. Although CNR can be configured with overlapping address range scopes, it cannot be used to allocate addresses from these scopes. |
version 12.0 no service pad service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname uBR7246 ! boot system flash slot0:ubr7200-p-mz.120-5.T boot system flash ! cable spectrum-group 1 frequency 40000000 cable spectrum-group 1 frequency 20000000 2 cable modulation-profile 3 request 0 16 1 8 16qam scrambler 152 no-diff 128 fixed uw16 cable modulation-profile 3 initial 5 34 0 48 16qam scrambler 152 no-diff 256 fixed uw16 cable modulation-profile 3 station 5 34 0 48 16qam scrambler 152 no-diff 256 fixed uw16 cable modulation-profile 3 short 5 75 6 8 16qam scrambler 152 no-diff 144 fixed uw8 cable modulation-profile 3 long 8 220 0 8 16qam scrambler 152 no-diff 160 fixed uw8 no cable qos permission create no cable qos permission update cable qos permission modems ip subnet-zero ip dhcp relay information option
! interface FastEthernet0/0 ip address 10.1.70.2 255.255.255.0 no ip directed-broadcast no ip mroute-cache ! ! interface Ethernet2/3 ip address 1.3.59.1 255.255.0.0 no ip directed-broadcast ! interface Cable5/0 ip address 172.1.71.1 255.255.255.0 secondary ip address 10.1.71.1 255.255.252.0 no ip directed-broadcast no ip route-cache no ip mroute-cache no keepalive no cable proxy-arp
cable helper-address 10.1.70.30 cable downstream annex B cable downstream modulation 64qam cable downstream interleave-depth 32 cable upstream 0 spectrum-group 1 cable upstream 0 modulation-profile 3 cable downstream frequency 531000000 cable upstream 0 frequency 28000000 cable upstream 0 power-level 0 no cable upstream 0 shutdown cable upstream 1 shutdown cable upstream 2 shutdown cable upstream 3 shutdown cable upstream 4 shutdown cable upstream 5 shutdown ! ! router eigrp 100 network 10.0.0.0 ! ip classless no ip http server ! ! ! line con 0 password cisco login transport input none line aux 0 line vty 0 4 password cisco login ! end
The command lines in the sample configuration file beginning with the string cable spectrum-group contain the critical elements necessary to set up spectrum management in your overall configuration:
cable spectrum-group 1 frequency 40000000 cable spectrum-group 1 frequency 20000000 2
In this case, the user has configured spectrum management group number "1" to be available to upstream channels. As defined by the two command lines above, the "preferred" choice is for the upstream to operate on a 40 MHz channel. If that channel is not suitable for the transmission scheme available, the upstream will automatically move over to transmitting at 20 MHz and increase the receive power rating by 2 dB.
The command lines in the sample configuration file beginning with the string cable modulation-profile contain the critical elements necessary to set up a modulation profile in your overall configuration:
cable modulation-profile 3 request 0 16 1 8 16qam scrambler 152 no-diff 128 fixed uw16 cable modulation-profile 3 initial 5 34 0 48 16qam scrambler 152 no-diff 256 fixed uw16 cable modulation-profile 3 station 5 34 0 48 16qam scrambler 152 no-diff 256 fixed uw16 cable modulation-profile 3 short 5 75 6 8 16qam scrambler 152 no-diff 144 fixed uw8 cable modulation-profile 3 long 8 220 0 8 16qam scrambler 152 no-diff 160 fixed uw8
In this case, the user has configured modulation profile number "3" to be available to upstream channels wherever they are configured to apply it. Note that this modulation profile has been configured to operate with a 16 QAM modulation scheme. The default modulation scheme for any upstream profile (if it is not set to 16 QAM) is QPSK.
Later in the configuration file example, upstream port 0 on the cable modem card installed in slot 5 utilizes both the spectrum management and the modulation profile configured in the sample.
cable upstream 0 spectrum-group 1 cable upstream 0 modulation-profile 3
version 12.0 service timestamps debug uptime service timestamps log uptime service password-encryption ! hostname newtown01-7246 ! boot system flash slot0:ubr7200-k1ps-mz.120-8.SC.bin boot system flash slot0: boot config slot0:C7246 boot bootldr slot0:ubr7200-boot-mz.120-8.SC.bin enable secret 5 <removed> enable password 7 <removed> ! cable flap-list size 4000 cable flap-list power-adjust threshold 3 cable flap-list aging 86400 cable spectrum-group 1 hop threshold 15 cable spectrum-group 1 frequency 26000000 cable spectrum-group 1 frequency 24000000 1 cable spectrum-group 1 frequency 22000000 2 no cable qos permission create no cable qos permission update cable qos permission modems ! ! ! ! clock timezone GMT 0 ip subnet-zero no ip source-route no ip finger ip telnet source-interface FastEthernet0/0 ! ! !
interface FastEthernet0/0 ip address 10.0.0.1 255.255.255.0 secondary ip address 209.187.212.2 255.255.255.252 no ip directed-broadcast no ip mroute-cache full-duplex no cdp enable ! interface Cable3/0 description Sunnyvale, CA ip address 209.187.213.1 255.255.255.0 secondary ip address 10.8.0.1 255.255.0.0 no ip directed-broadcast no ip mroute-cache no keepalive cable spectrum-group 1 cable dhcp-giaddr policy cable helper-address 209.187.212.12 cable downstream annex B cable downstream modulation 64qam cable downstream interleave-depth 32 cable downstream frequency 687000000 cable upstream 0 description Sunnyvale 1-5 cable upstream 0 power-level 0 no cable upstream 0 shutdown cable upstream 1 description Sunnyvale 6-10 cable upstream 1 power-level 0 no cable upstream 1 shutdown cable upstream 2 description Sunnyvale 1-6 cable upstream 2 power-level 0 no cable upstream 2 shutdown cable upstream 3 description Sunnyvale 7-11 cable upstream 3 power-level 0 no cable upstream 3 shutdown cable upstream 4 description Sunnyvale 12-17 cable upstream 4 power-level 0 no cable upstream 4 shutdown cable upstream 5 description Sunnyvale 18-23 cable upstream 5 power-level 0 no cable upstream 5 shutdown ! interface Cable4/0 description Santa Clara, CA ip address 207.252.148.1 255.255.255.0 secondary ip address 10.9.0.1 255.255.0.0 no ip directed-broadcast no ip mroute-cache no keepalive cable spectrum-group 1 cable dhcp-giaddr policy cable helper-address 209.187.212.12 cable downstream annex B cable downstream modulation 64qam cable downstream interleave-depth 32 cable downstream frequency 687000000 cable upstream 0 description Santa Clara 1-8 cable upstream 0 power-level 0 cable upstream 0 shutdown cable upstream 1 description Santa Clara 1-7 cable upstream 1 power-level 0 no cable upstream 1 shutdown cable upstream 2 description Santa Clara 8-13 cable upstream 2 power-level 0 no cable upstream 2 shutdown cable upstream 3 description Santa Clara14-19 cable upstream 3 power-level 0 no cable upstream 3 shutdown able upstream 4 description Santa Clara 20-26 cable upstream 4 power-level 0 no cable upstream 4 shutdown cable upstream 5 description Santa Clara 27-33 cable upstream 5 power-level 0 no cable upstream 5 shutdown ! interface Cable5/0 description San Jose, CA ip address 207.252.149.1 255.255.255.0 secondary ip address 10.10.0.1 255.255.0.0 no ip directed-broadcast no ip mroute-cache no keepalive cable spectrum-group 1 cable dhcp-giaddr policy cable helper-address 209.187.212.12 cable downstream annex B cable downstream modulation 64qam cable downstream interleave-depth 32 cable downstream frequency 687000000 cable upstream 0 description Willow Glen 1-8 cable upstream 0 power-level 0 no cable upstream 0 shutdown cable upstream 1 description Willow Glen 9-16 cable upstream 1 power-level 0 no cable upstream 1 shutdown cable upstream 2 description Willow Glen 17-24 cable upstream 2 power-level 0 no cable upstream 2 shutdown cable upstream 3 description Willow Glen 25-32 cable upstream 3 power-level 0 no cable upstream 3 shutdown cable upstream 4 description Evergreen 1-8 cable upstream 4 power-level 0 no cable upstream 4 shutdown able upstream 5 description Evergreen 9-17 cable upstream 5 power-level 0 no cable upstream 5 shutdown ! interface Cable6/0 description Morgan Hill, CA ip address 209.187.214.1 255.255.255.0 secondary ip address 10.11.0.1 255.255.0.0 no ip directed-broadcast no ip mroute-cache no keepalive cable spectrum-group 1 cable dhcp-giaddr policy cable helper-address 209.187.212.12 cable downstream annex B cable downstream modulation 64qam cable downstream interleave-depth 32 cable downstream frequency 687000000 cable upstream 0 description Santa Theresa 1-5 cable upstream 0 power-level 0 cable upstream 0 shutdown cable upstream 1 description Santa Theresa 6-10 cable upstream 1 power-level 0 cable upstream 1 shutdown cable upstream 2 description Santa Theresa 11-14 cable upstream 2 power-level 0 cable upstream 2 shutdown cable upstream 3 description Santa Theresa 1-5 cable upstream 3 power-level 0 no cable upstream 3 shutdown cable upstream 4 description Santa Theresa 6-11 cable upstream 4 power-level 0 no cable upstream 4 shutdown cable upstream 5 description Santa Theresa 12-17 cable upstream 5 power-level 0 no cable upstream 5 shutdown ! ip classless ip route 0.0.0.0 0.0.0.0 209.187.212.1 ip route 0.0.0.0 0.0.0.0 Null0 255 ! > no cdp run > snmp-server engineID local 0000000902000030190E0900 snmp-server community <removed> RO snmp-server location San Jose, CA snmp-server contact Jim Smith snmp-server chassis-id 01 ! banner login ^C Warning! Unauthorized use of this system is prohibited. = You will be prosecuted to the fullest extent of = the law.^C alias exec qos show cable qos profile alias exec scm show cable modem alias exec noise show cable modem detail ! line con 0 transport input none line aux 0 line vty 0 4 exec-timeout 0 0 password 7 <removed> login ! ntp clock-period 17179915 ntp update-calendar ntp max-associations 2000 ntp server 129.7.1.66 source FastEthernet0/0 prefer end
The Cisco CMTS supports 56-bit and 40-bit encryption/decryption; 56 bit is the default. After you choose a CMTS image that supports BPI, BPI is enabled by default for the Cisco uBR7200 series. Key commands that appear in the Cisco uBR7200 series configuration file that denote encryption/decryption is supported include:
int cable 2/0 cable privacy kek grace-time 800 cable privacy kek life-time 750000 cable privacy tek grace-time 800 cable privacy tek life-time 56000 cable privacy enable cable privacy mandatory
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Note The cable modem must also support encryption/decryption. |
When baseline privacy is enabled, the Cisco CMTS routes encrypted/decrypted packets from a host or peer to another host or peer. BPI is configured with key encryption keys (keks) and traffic encryption keys (teks). A kek is assigned to a cable modem based on the cable modem's service identifier (SID) and permits the cable modem to connect to the Cisco CMTS when baseline privacy is activated. The tek is assigned to a cable modem when its kek has been established. The tek is used to encrypt data traffic between the cable modem and the Cisco CMTS.
Keks and teks can be set to expire based on a gracetime or a lifetime value. A gracetime key is used to assign a temporary key to a cable modem to access the network. A lifetime key is used to assign a more permanent key to a cable modem. Each cable modem that has a lifetime key assigned will request a new lifetime key from the Cisco CMTS before the current one expires.
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Tips Use the show cable modem command to identify a cable modem with encryption/decryption enabled. The online(pk) output of this command reveals a cable modem that is registered with BPI enabled and a KEK assigned. The online(pt) output reveals a cable modem that is registered with BPI enabled and a TEK assigned. |
Should you want to change the Cisco uBR7200 series default of 56-bit encryption/decryption to 40-bit, use the "40-bit-des" option:
CMTS(config-if)#cable privacy ? 40-bit-des select 40 bit DES ^^^^^^^^^^ authenticate-modem turn on BPI modem authentication authorize-multicast turn on BPI multicast authorization kek KEK Key Parms mandatory force privacy be mandatory tek TEK Key Parms
Software then generates a 40-bit DES key, where the DES key that is generated and returned masks the first 16-bits of the 56-bit key to zero in software. To return to 56-bit encryption/decryption after changing to 40-bit, enter the no command preceding the "40-bit-des" option.
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Caution Cisco uBR7200 series telco return images that support BPI, do not support encryption/decryption in the telco return path. |
The Cisco uBR7200 series supports EuroDOCSIS channel plans when using the MC16E cable modem card. Key commands that appear in the Cisco uBR7200 series configuration file that denote EuroDOCSIS operation include:
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Note The following Cisco IOS releases support EuroDOCSIS operation using the MC16E cable modem card: 12.0(7)T, 12.0(7)XR2, 12.1 Mainline, 12.1(1a)T1 and higher; SC train images including 12.0(8)SC, 12.0(9)SC, and higher. |
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Tips In contrast to other cable modem cards where you set the downstream modulation and interleave depth, the downstream interleave value is fixed for the MC16E and cannot be configured. The MC16E also does not support enhanced spectrum management. |
A sample EuroDOCSIS configuration file follows:
! version 12.0 service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname R7732-06-uBR7246-CE ! ! cable modulation-profile 1 request 0 16 1 8 16qam scrambler 152 no-diff 128 fixed uw16 cable modulation-profile 1 initial 5 34 0 48 16qam scrambler 152 no-diff 256 fixed uw16 cable modulation-profile 1 station 5 34 0 48 16qam scrambler 152 no-diff 256 fixed uw16 cable modulation-profile 1 short 6 75 6 8 16qam scrambler 152 no-diff 144 fixeduw8 cable modulation-profile 1 long 8 220 0 8 16qam scrambler 152 no-diff 160 fixeduw8 cable modulation-profile 2 request 0 16 1 8 qpsk scrambler 152 no-diff 64 fixeduw8 cable modulation-profile 2 initial 5 34 0 48 qpsk scrambler 152 no-diff 128 fixed uw16 cable modulation-profile 2 station 5 34 0 48 qpsk scrambler 152 no-diff 128 fixed uw16 cable modulation-profile 2 short 5 75 6 8 qpsk scrambler 152 no-diff 72 fixed uw8 cable modulation-profile 2 long 8 220 0 8 qpsk scrambler 152 no-diff 80 fixed uw8 ! no cable qos permission create no cable qos permission update cable qos permission modems ! ! ! ! ip subnet-zero ip host abrick 223.255.254.254 ! ! ! interface Loopback0 ip address 222.2.4.1 255.255.255.255 no ip directed-broadcast !
interface Loopback2 ip address 111.0.4.2 255.255.255.255 no ip directed-broadcast ! interface FastEthernet0/0 ip address 1.8.93.9 255.255.0.0 no ip directed-broadcast ! interface Cable3/0 ip address 3.214.1.1 255.255.255.0 no ip directed-broadcast load-interval 30 no keepalive cable spectrum-group 1 cable helper-address 1.8.93.100
cable downstream annex A cable downstream modulation 64qam cable downstream frequency 669000000
cable upstream 0 frequency 5008000 cable upstream 0 power-level 0 no cable upstream 0 shutdown cable upstream 1 frequency 10000000 cable upstream 1 power-level 0 no cable upstream 1 shutdown cable upstream 2 frequency 15008000 cable upstream 2 power-level 0 no cable upstream 2 shutdown cable upstream 3 frequency 20000000 cable upstream 3 power-level 0 no cable upstream 3 shutdown cable upstream 4 frequency 55008000 cable upstream 4 power-level 0 no cable upstream 4 shutdown cable upstream 5 frequency 60000000 cable upstream 5 power-level 0 no cable upstream 5 shutdown ! ip default-gateway 1.8.0.1 ip classless ip route 223.255.254.254 255.255.255.255 1.8.0.1 ! snmp-server engineID local 00000009020000D0BA1EED00 snmp-server community public RO snmp-server community private RW ! alias exec scm show cable modem ! line con 0 exec-timeout 0 0 transport input none line aux 0 line vty 0 4 password lab login ! end
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Tips To properly transmit and receive encrypted/decrypted traffic, each peer in the VPN must activate encryption/decryption and have matching access key strings. |
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Note The Cisco CMTS allows encrypted traffic to pass over the cable network (and often the Internet) from one peer to the other, based on a routing table setup in its configuration file. |
In the example that follows, a Cisco uBR7200 series connects two branch office networks to their respective head office using a GRE tunnel.
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Note Each branch office network is connected to the Cisco uBR7200 series using the cable interface. Each customer is assigned a separate subinterface over the physical cable interface. |
The cable interface number 3 has been configured with two subinterfaces. Each subinterface connects to a customer Small Office Home Office (SOHO) cable modem:
! interface Cable3/0 no ip address no ip directed broadcasr no keepalive ip route-cache policy !(To configure policy based route-cache on subinterfaces. This command not available on subinterfaces.) cable downstream annex B cable downstream modulation 64qam cable downstream interleave-depth 32 cable upstream 0 power-level 0 no cable upstream 0 shutdown !(While configuring the physical interface IP address and IP helper address parameters must not be entered.) interface c3/0.1 ip address 172.100.1.1 255.255.255.0 cable helper address 11.0.0.2 ip policy route-map customer1 no ip directed-broadcast no cable proxy-arp no cable ip-multicast-echo
interface c3/0.2 ip address 174.100.1.1 255.255.255.0 ip helper address 11.0.0.2 ip policy route-map customer2 no ip directed-broadcast no cable proxy-arp no cable ip-multicast-echo interface serial 0 ip address 151.145.1.1 255.255.255.0 interface tunnel 0 ip address 172.100.3.1 255.255.255.252 tunnel source s0 tunnel destination 151.145.2.1 interface tunnel 1 ip address 174.100.3.1 255.255.252 tunnel source s0 tunnel destination 151.145.3.1 ! configure route maps to forward traffic coming over c3/0.1 and c3/0.2 to go over the tunnel 0 and ! tunnel 1 respectively. route-map customer1 permit 10 match ip address 101 set ip next-hop 11.1.1.1 route-map customer1 permit 20 match ip address 102 set ip next-hop 172.100.3.2 route-map customer2 permit 10 match ip address 101 set ip next-hop 11.1.1.1 !(traffic to go over the interface that connects to DHCP/DNS/TFTP Server) route-map customer2 permit 20 match ip address 102 set ip next-hop 174.100.3.2 access-list 101 permit ip any 11.1.1.0 0.0.0.255 !(matches traffic destined for DHCP/DNS/TFTP server) access-list 102 permit ip any any !(any other traffic that is not meant for DHCP/DNS/TFTP server) ip route 151.145.0.0 255.255.0.0 s0 <- static route to connect to IP Cloud.
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Note You can use set ip default next-hop a.b.c.d to avoid setting up two access lists. The access list can match all IP traffic and the route-map command should use set ip default next-hop a.b.c.d. This works with CEF and process switching, not with cache-based fast switching. The packets are first routed normally using the routing table. If a route is not found, then they are forwarded to a.b.c.d which is the IP address at the other end of the tunnel. |
interface ethernet0 ip address 172.100.2.1 255.255.255.0 interface serial 0 ip address 151.145.2.1 255.255.255.0 interface tunnel 0 ip address 172.100.3.2 255.255.255.252 tunnel source s0 tunnel destination 151.145.1.1 ip route 151.145.0.0 255.255.0.0 s0 !(static route to connect to IP Cloud)
interface ethernet0 ip address 174.100.2.1 255.255.255.0 interface serial 0 ip address 151.145.3.1 255.255.255.0 interface tunnel 0 ip address 174.100.3.2 255.255.255.252 tunnel source s0 tunnel destination 151.145.1.1 ip route 151.145.0.0 255.255.0.0 s0 !(static route to connect to IP Cloud) exec-timeout 0 0 login transport input none line aux 0 line vty 0 4 password lab login ! scheduler allocate 988 200 end
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Caution In certain countries, the provisioning of voice telephony over the Internet or use of these products might be prohibited and/or subject to laws, regulations or licenses, including requirements applicable to the use of the products under telecommunications and other laws and regulations; customers must comply with all such applicable laws in the countries where customers intend to use the product. |
Following is a sample voice over IP configuration file for the Cisco uBR7246:
! version 12.0 no service pad service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname twoslot ! enable password **** ! ! ip subnet-zero no ip domain-lookup ip host abrick 223.255.254.254 ip host muck 255.255.255.255 ip host keyer 223.255.254.254 ip host bell 223.255.254.253 ! ! ! interface FastEthernet0/0 ip address 2.2.2.2 255.255.255.0 no ip directed-broadcast no ip mroute-cache shutdown ! interface Ethernet1/0 ip address 1.11.8.1 255.255.0.0 ip broadcast-address 1.11.255.255 ip helper-address 223.255.254.254 no ip directed-broadcast no ip mroute-cache ! interface Ethernet1/1 ip address 10.20.122.2 255.255.255.192 ip helper-address 10.0.0.2 no ip directed-broadcast ! interface Ethernet1/2 no ip address no ip directed-broadcast shutdown ! interface Ethernet1/3 no ip address no ip directed-broadcast shutdown ! interface Cable2/0 ip address 20.20.20.20 255.255.255.0 no ip directed-broadcast no keepalive cable downstream modulation 64qam cable upstream 0 frequency 10000000 cable upstream 0 power-level 0 no cable upstream 0 shutdown cable upstream 1 frequency 10000000 cable upstream 1 power-level 0 no cable upstream 1 shutdown cable upstream 2 shutdown cable upstream 3 shutdown cable upstream 4 shutdown cable upstream 5 shutdown ! ip default-gateway 1.11.0.1 ip classless ip route 0.0.0.0 0.0.0.0 10.20.122.1 ip route 223.255.254.254 255.255.255.255 1.11.0.1 ip http server ! ! ! ! line con 0 exec-timeout 0 0 transport input none line aux 0 line vty 0 4 login line vty 5 11 login ! end
Clock support enables the Cisco uBR7246 VXR router to synchronize to an external timing reference and distribute clock to Cisco MC16S and MC16E cable modem cards. The synchronized DOCSIS time stamps are then passed downstream to all cable modems.
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Note Clock support is designed for cable networks running VoIP applications where synchronized timing is vital to maintain voice quality. The clocking feature is supported only on a Cisco uBR7246 VXR chassis that contains the clock card and uses Cisco IOS Release 12.1(1a)T1 or higher. The cable modem must also support VoIP and the clock mode. |
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Tips No configuration tasks are required to use the clock card after it is installed in the Cisco uBR7246 VXR. When the clock card is present, it becomes the midplane TDM clock reference source. |
Key commands that appear in the Cisco uBR7246 VXR configuration file that denote clock support include:
cable clock source-midplane no cable clock force primary no cable clock force secondary
Determine if the cable modem requires the following setup:
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Note Some vendors' telco return cable modems cannot receive traffic over the same downstream channel as cable modems operating on a two-way data system. In these instances, segment your cable plant to allow more than one downstream channel. |
The following elements must be configured for a telco return network:
This sample Cisco uBR7200 series configuration file supports telco return:
! version 12.0 service timestamps debug uptime service timestamps log uptime service password-encryption ! hostname uBR7246 ! boot system flash slot0:ubr7200-p-mz.********** boot system flash logging buffered 100000 debugging aaa new-model aaa authentication login default radius enable aaa authentication login vty line aaa accounting update newinfo aaa accounting exec default start-stop radius aaa accounting commands 15 default start-stop radius aaa accounting network default start-stop radius aaa accounting system default start-stop radius enable secret guess_my_password_ha_ha_ha. ! no cable qos permission create no cable qos permission update cable qos permission modems ip subnet-zero no ip finger no ip domain-lookup ! ! !
interface Loopback0 ip address 24.1.2.246 255.255.255.0 no ip directed-broadcast ! interface FastEthernet0/0 no ip address no ip directed-broadcast shutdown media-type MII full-duplex ! interface Hssi1/0 ip unnumbered Loopback0 no ip directed-broadcast ! interface Cable3/0 ip address 10.1.1.1 255.255.255.0 no ip directed-broadcast cable helper-address 24.1.1.84 no keepalive cable downstream annex B cable downstream modulation 64qam cable downstream interleave-depth 32 cable downstream frequency 687000000 cable upstream 0 frequency 13008000 no cable upstream 0 shutdown cable upstream 1 shutdown cable upstream 2 shutdown cable upstream 3 shutdown cable upstream 4 shutdown cable upstream 5 shutdown ! interface Cable6/0 ip address 172.16.1.1 secondary ip address 10.1.1.1 no ip directed-broadcast cable helper-address 24.1.1.84 no keepalive cable downstream annex B cable downstream modulation 64qam cable downstream interleave-depth 32 cable downstream frequency 687000000 cable upstream 0 frequency 13008000 no cable upstream 0 shutdown cable telco-return enable cable telco-return spd 1 factory-default cable telco-return spd 1 dhcp-authenticate cable telco-return spd 1 dhcp-server 24.1.1.84 cable telco-return spd 1 ppp-authenticate chap cable telco-return spd 1 phonenum 918005555555 cable telco-return spd 1 phonenum 18005555555 cable telco-return spd 1 username test cable telco-return spd 1 password test ! router ospf 100 network 10.0.0.0 0.255.255.255 area 0 network 24.1.0.0 0.0.255.255 area 0 ! ip classless ip route 0.0.0.0 0.0.0.0 24.1.2.21 ! logging 24.1.1.78 snmp-server community public RO snmp-server community favorite_server_community RW snmp-server location favorite_location ! radius-server host 24.1.1.78 auth-port 1645 acct-port 1646 radius-server key radius_server_key ! line con 0 password No need to change; this is encrypted already. transport input none flowcontrol software line aux 0 password No need to change; this is encrypted already. flowcontrol hardware line vty 0 4 password No need to change; this is encrypted already. login authentication vty ! end
The command lines in the sample configuration file beginning with the string aaa contain the critical elements for authentication, authorization, and accounting (AAA) setup:
aaa new-model aaa authentication login default radius enable aaa authentication login vty line aaa accounting update newinfo aaa accounting exec default start-stop radius aaa accounting commands 15 default start-stop radius aaa accounting network default start-stop radius aaa accounting system default start-stop radius
The command lines in the sample configuration file beginning with the string cable telco-return contain the critical elements to minimally set up the telco return network:
cable telco-return enable cable telco-return spd 1 factory-default cable telco-return spd 1 dhcp-authenticate cable telco-return spd 1 dhcp-server 24.1.1.84 cable telco-return spd 1 ppp-authenticate chap cable telco-return spd 1 phonenum 918005555555 cable telco-return spd 1 phonenum 18005555555 cable telco-return spd 1 username test cable telco-return spd 1 password test
First, activate telco return functionality with the enable keyword. Then activate DHCP authentication and identify the location of the DHCP server, provide up to three telephone numbers for dial-in access, specify the type of PPP authentication for upstream transmission, and provide the user name and password to authorize login to the dial-up network.
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Note PPP is the only upstream communication medium offered between a remote cable modem and a dial-up access server. You can, however, configure a Challenge Handshake Authentication Protocol (CHAP), or Password Authentication Protocol (PAP) authentication method, or both methods for upstream data transmission. |
The command lines in the sample configuration file beginning with the string snmp-server contain the critical elements for minimal SNMP-server setup:
logging 24.1.1.78 snmp-server community public RO snmp-server community favorite_server_community RW snmp-server location favorite_location
The command lines in the sample configuration file beginning with the string radius-server contain the critical elements for minimal RADIUS dial server setup:
radius-server host 24.1.1.78 auth-port 1645 acct-port 1646 radius-server key radius_server_key
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Note For more detailed information regarding AAA, telco return, SNMP server, and RADIUS dial server software functionality, you can access Cisco IOS software configuration documentation on the World Wide Web at http://www.cisco.com, http://www-china.cisco.com, or http://www-europe.cisco.com. |
This section provides the following 1+1 redundancy configuration examples:
Current configuration: ! version 12.0 no service pad service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname ubr7246-2 ! boot system tftp /tftpboot/annex4/jzang/ubr7200-p-mz 10.0.0.2 ! no cable qos permission create no cable qos permission update cable qos permission modems ! ip subnet-zero no ip domain-lookup ip host abrick 223.255.254.254 ! ! key chain cat key 1 key-string abcdefg key 2 key-string 123456789 ! interface FastEthernet0/0 ip address 10.20.111.11 255.255.255.248 no ip directed-broadcast no ip mroute-cache no keepalive half-duplex ! interface Ethernet1/0 ip address 1.1.11.2 255.255.255.248 no ip directed-broadcast no ip mroute-cache ! interface Ethernet1/1 no ip address no ip directed-broadcast no ip mroute-cache shutdown ! interface Ethernet1/2 no ip address no ip directed-broadcast no ip mroute-cache shutdown ! interface Ethernet1/3 no ip address no ip directed-broadcast no ip mroute-cache shutdown ! interface Cable4/0 ip address 10.20.111.129 255.255.255.240 no ip directed-broadcast ip helper-address 10.0.0.2 cable downstream annex B cable downstream modulation 64qam cable downstream interleave-depth 32 cable downstream frequency 441000000 cable upstream 0 frequency 11408000 cable upstream 0 power-level 8 no cable upstream 0 shutdown cable upstream 1 shutdown cable upstream 2 shutdown cable upstream 3 shutdown cable upstream 4 shutdown cable upstream 5 shutdown hccp 1 working 1 hccp 1 ds-switch 1 wavecom 1.1.11.3 2 1.1.11.3 1 hccp 1 authentication md5 hccp 1 authentication key-chain cat ! router eigrp 1 passive-interface Cable4/0 network 10.20.111.8 0.0.0.7 network 10.20.111.128 0.0.0.15 ! ip classless no ip http server ! snmp-server engineID local 00000009020000D058277000 snmp-server community private RW snmp-server manager ! line con 0 exec-timeout 0 0 transport input none line aux 0 stopbits 1 line vty 0 4 login ! end
Current configuration: ! version 12.0 no service pad service timestamps debug uptime service timestamps log uptime no service password-encryption ! hostname ubr7246-1 ! boot system tftp /tftpboot/annex4/jzang/ubr7200-p-mz 10.0.0.2 ! no cable qos permission create no cable qos permission update cable qos permission modems ! ip subnet-zero no ip domain-lookup ip host abrick 223.255.254.254 ! key chain cat key 1 key-string abcdefg key 2 key-string 123456789 ! interface FastEthernet0/0 ip address 10.20.111.10 255.255.255.248 no ip directed-broadcast no ip mroute-cache no keepalive half-duplex ! interface Ethernet1/0 ip address 1.1.11.1 255.255.255.248 no ip directed-broadcast no ip mroute-cache ! interface Ethernet1/1 no ip address no ip directed-broadcast no ip mroute-cache shutdown ! interface Ethernet1/2 no ip address no ip directed-broadcast no ip mroute-cache shutdown ! interface Ethernet1/3 no ip address no ip directed-broadcast no ip mroute-cache shutdown ! interface Cable3/0 no ip address no ip directed-broadcast ip helper-address 10.0.0.2 shutdown cable downstream annex B cable downstream modulation 64qam cable downstream interleave-depth 32 cable downstream frequency 441000000 cable upstream 0 frequency 11408000 cable upstream 0 power-level 10 no cable upstream 0 shutdown hccp 2 working 2 hccp 2 ds-switch 2 wavecom 1.1.11.3 5 1.1.11.3 6 ! interface Cable4/0 ip address 10.20.111.129 255.255.255.240 no ip directed-broadcast ip helper-address 10.0.0.2 cable downstream annex B cable downstream modulation 64qam cable downstream interleave-depth 32 cable downstream frequency 441000000 cable downstream channel-id 0 cable upstream 0 frequency 11408000 cable upstream 0 power-level 8 no cable upstream 0 shutdown cable upstream 1 shutdown cable upstream 2 shutdown cable upstream 3 shutdown cable upstream 4 shutdown cable upstream 5 shutdown hccp 1 protect 1 10.20.111.11 hccp 1 ds-switch 1 wavecom 1.1.11.3 1 1.1.11.3 2 hccp 1 authentication md5 hccp 1 authentication key-chain cat ! router eigrp 1 passive-interface Cable4/0 network 10.20.111.8 0.0.0.7 network 10.20.111.128 0.0.0.15 ! ip classless no ip http server ! snmp-server engineID local 00000009020000505461E400 snmp-server community private RW snmp-server manager ! line con 0 exec-timeout 0 0 transport input none line aux 0 stopbits 1 line vty 0 4 login ! end
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Note You can optionally use the show hccp or show hccp brief commands but Cisco recommends that you take advantage of the detailed output that is automatically displayed when you use the show hccp detail privileged EXEC command. |
Router# show hccp detail
Cable3/0 - Group 2 Working, disabled, blocking
authentication none
hello time 2000 msec, hold time 6000 msec
sync time 1000 msec, suspend time 120000 msec
switch time 240000 msec retries 5
local state is Init
tran 0, out staticsync
last switch reason is none
Member 2 non-functional
ip addr: working unknown, protect unknown
downstream wavecom (1.1.11.3/5, 1.1.11.3/6), upstream none
tran #: SYNC 0, last SYNC_ACK 0, last HELLO_ACK 0
hold timer expires in never
Cable4/0 - Group 1 Protect, enabled, blocking
authentication md5, key-chain "cisco1"
hello time 2000 msec, hold time 6000 msec
sync time 1000 msec, suspend time 120000 msec
local state is Learn, non-revertive
tran 330, out staticsync
last switch reason is none
hello timer expires in 00:00:01.476
Member 1 standby
ip addr: working 10.20.111.11, protect 10.20.111.10
downstream wavecom (1.1.11.3/1, 1.1.11.3/2), upstream none
tran #: SYNC 0, last SYNC_ACK 16, last HELLO_ACK 330
hold timer expires in 00:00:05.140
The Cisco uBR7200 IOS Release 12.1(3)EC has one preconfigured modulation profile resident in memory, which defines a typical profile for QPSK modulation. In order to use the Dynamic Upstream Modulation feature, a second profile must be created that is unique from the first profile and typically provides a higher modulation scheme.
The following example is a modulation profile for 16QAM, in which the initial, request, and station maintenance messages are sent as QPSK, while the short and long data packets are sent as 16QAM. 16QAM modulation is more bandwidth-efficient than QPSK, but QPSK is more robust than 16QAM.
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Note The upstream request and station maintenance messages use less time on the cable network when configured in QPSK for symbol rates of 640, 1280 and 2560 Ksymbols/sec, Thus, these messages are actually more efficient when used in QPSK mode and they ensure a more reliable modem connection. The upstream initial maintenance message takes exactly the same amount of time on the cable network no matter how it is configured. Modems will connect more quickly and experience fewer cycles of power-adjustment during initial maintenance if the system is set for QPSK. |
Router#configure terminal Router(config)#cable modulation-profile 2 request 0 16 1 8 qpsk scrambler 152 no-diff 64 fixed uw8 Router(config)#cable modulation-profile 2 initial 5 34 0 48 qpsk scrambler 152 no-diff 128 fixed uw16 Router(config)#cable modulation-profile 2 station 5 34 0 48 qpsk scrambler 152 no-diff 128 fixed uw16 Router(config)#cable modulation-profile 2 short 6 75 6 8 16qam scrambler 152 no-diff 72 fixed uw8 Router(config)#cable modulation-profile 2 long 8 220 0 8 16qam scrambler 152 no-diff 160 fixed uw8
In the following example, all message types are carried with 16QAM modulation. While this modulation offers a consistent modulation scheme for all five types of messages, the added length of the 16QAM preamble offsets the increased bandwidth efficiency of the MAC data message for the station maintenance messages and bandwidth request messages.
Router#configure terminal Router(config)#cable modulation-profile 2 request 0 16 1 8 16qam scrambler 152 no-diff 128 fixed uw16 Router(config)#cable modulation-profile 2 initial 5 34 0 48 16qam scrambler 152 no-diff 256 fixed uw16 Router(config)#cable modulation-profile 2 station 5 34 0 48 16qam scrambler 152 no-diff 256 fixed uw16 Router(config)#cable modulation-profile 2 short 5 75 6 8 16qam scrambler 152 no-diff 144 fixed uw8 Router(config)#cable modulation-profile 2 long 8 220 0 8 16qam scrambler 152 no-diff 160 fixed uw8
Next, add the cable upstream port-number modulation-profile primary profile-number secondary profile-number command to the appropriate interface(s). In this example, modulation-profile 2 is for 16QAM modulation and profile 1 is for QPSK modulation.
Router#configure terminal Router(config)#interface Cable6/0 Router(config-if)#cable upstream 0 modulation-profile 2 1
The configuration commands are:
Router(config-if)#cable monitor [outbound | incoming] [timestamp] interface <interface> {access-list <name | number> | sid <n> | mac-addr <address> | upstream <n> }[ packet-type { mac [type { map-req | map-grant | dsa | dsc | dsd ... } ] | data packet-header {ethernet | docsis } } ]
Enter configuration commands, one per line. End with CNTL/Z.
Router#conf t Router(config)#int c5/0 Router(config-if)#cable monitor ? incoming Monitor incoming packets outbound Monitor outbound packets timestamp Enable packet timestamping interface Interface to forward monitored packets Router(config-if)#cable monitor incoming ? timestamp Enable packet timestamping interface Interface to forward monitored packets Router(config-if)#cable monitor incoming timestamp ? nterface Interface to forward monitored packets Router(config-if)#cable monitor incoming timestamp interface e1/0 ? access-list IP access list name mac-addr MAC address of the device monitored sid Service ID to be monitored upstream Upstream port to monitor Router(config-if)#cable monitor incoming timestamp interface e1/0 sid 2 packet-type ? mac Monitor mac packets data Monitor data packets <cr> Router(config-if)#cable monitor incoming timestamp interface e1/0 sid 2 packet-type mac ? type Monitor selected mac packets <cr> Router(config-if)#cable monitor incoming timestamp interface e1/0 sid 2 packet-type mac type ? map-req Monitor Requests map-grant Monitor Grants dsa Monitor dynamic service addition dsc Monitor dynamic service change dsd Monitor dynamic service deletion Router(config-if)#cable monitor incoming timestamp interface e1/0 sid 2 packet-type mac type map-req
Show CLI :
Router#show interface cable 5/0 monitor US/ Time Outbound Flow Flow Type Flow Packet MAC MAC Encap DS Stmp Interface Type Identifier Extn. Type Extn. Type Type all yes Et1/0 mac-addr 0050.5462.008c yes data no - ethernet us yes Et1/0 acc-list 300 no - no - - us no Et1/0 sid 2 yes mac yes map-grant - all no Et1/0 acc-list rrr no - no - - all no Et1/0 mac-addr 0042.b013.008c yes data no - ethernet all no Et1/0 upstream 0 yes data no - docsis
***TBD***
After you have minimally configured the Cisco CMTS, refer to "Understanding System Operations" for more advanced configuration instructions. Also refer to "Troubleshooting the System" for information on troubleshooting your initial configuration.
For instructions on configuration of port adapters, refer to the respective installation document that shipped with the port adapter. For specific information on system and interface configuration, refer to the publications listed in the "If You Need More Information" section.
Posted: Mon Oct 2 13:21:46 PDT 2000
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