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This chapter describes how to configure ATM on the Cisco 2600 series, Cisco 3600 series, Cisco 4500, Cisco 4700, Cisco 7200 series, and Cisco 7500 series routers.
To configure routers that use a serial interface for ATM access through an ATM data service unit (ADSU), see the section "Configure ATM Access over a Serial Interface" later in this chapter.
For a complete description of the ATM commands in this chapter, refer to the "ATM Commands" chapter of the Wide-Area Networking Command Reference. To locate documentation of other commands that appear in this chapter, use the command reference master index or search online.
For information about Switched Multimegabit Data Service (SMDS) support, refer to the "SMDS Commands" chapter in the Wide-Area Networking Command Reference.
For information about configuring LAN emulation (LANE) for ATM, refer to the "Configuring LAN Emulation" chapter in the Cisco IOS Switching Services Configuration Guide. For information about LANE commands, refer to the "LAN Emulation Commands" chapter in the Cisco IOS Switching Services Command Reference.
To configure ATM, complete the tasks in the following sections. The first task is required, and then you must configure at least one PVC or SVC. The virtual circuit options you configure must match in three places: on the router, on the ATM switch, and at the remote end of the PVC or SVC connection. The remaining tasks are optional.
See the "ATM Configuration Examples" section at the end of this chapter for configuration examples.
This section describes how to begin configuring an ATM interface. For the AIP, all ATM port adapters, and the 1-port ATM-25 network module, the port number is always 0. For example, the slot/port address of an ATM interface on an AIP installed in slot 1 is 1/0.
To begin to configure the ATM interface, use the following commands beginning in privileged EXEC mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| configure terminal | At the privileged EXEC prompt, enter global configuration mode from the terminal. | ||
|
or interface atm slot/port-adapter/0 or interface atm number | Specify the ATM interface using the appropriate format of the interface atm command.1 | ||
| If IP routing is enabled on the system, optionally assign a source IP address and subnet mask to the interface. |
To enable the ATM interface, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
The no shutdown command passes an enable command to the ATM interface, which then begins segmentation and reassembly (SAR) operations. It also causes the ATM interface to configure itself based on the previous configuration commands sent.
To use a permanent virtual circuit (PVC), you must configure the PVC into both the router and the ATM switch. PVCs remain active until the circuit is removed from either configuration.
All virtual circuit characteristics listed in the "Wide-Area Networking Overview" chapter apply to these PVCs. When a PVC is configured, all the configuration options are passed on to the ATM interface. These PVCs are writable into the nonvolatile RAM (NVRAM) as part of the Route Processor (RP) configuration and are used when the RP image is reloaded.
Some ATM switches might have point-to-multipoint PVCs that do the equivalent of broadcasting. If a point-to-multipoint PVC exists, then that PVC can be used as the sole broadcast PVC for all multicast requests.
To configure a PVC, perform the tasks in the following sections. The first two tasks are required; the other tasks are optional.
To create a PVC on the ATM interface and enter interface-ATM-VC configuration mode, use the following command beginning in interface configuration mode:
| Command | Purpose |
|---|---|
Configure a new ATM PVC by assigning a name (optional) and VPI/VCI numbers. Enter interface-ATM-VC configuration mode. Optionally configure ILMI, QSAAL, or SMDS encapsulation. |
Once you specify a name for a PVC, you can re-enter the interface-ATM-VC configuration mode by simply entering pvc name.
See examples of PVC configurations in the section "ATM Configuration Examples" at the end of this chapter.
The ATM interface supports a static mapping scheme that identifies the network address of remote hosts or routers. This section describes how to map a PVC to an address, which is a required task for configuring a PVC.
To map a protocol address to a PVC, use the following command in interface-ATM-VC configuration mode:
| Command | Purpose |
|---|---|
Map a protocol address to a PVC. |
See examples of PVC configurations in the section "ATM Configuration Examples" at the end of this chapter.
To configure the ATM adaptation layer (AAL) and encapsulation type, use the following command beginning in interface-ATM-VC configuration mode:
| Command | Purpose |
|---|---|
Configure the ATM adaptation layer (AAL) and encapsulation type. |
For a list of AAL types and encapsulations supported for the aal-encap argument, refer to the encapsulation command in the "ATM Commands" chapter of the Wide-Area Networking Command Reference. The global default is AAL5 with SNAP encapsulation.
The supported traffic parameters are part of the following service categories: Available Bit Rate (ABR), Unspecified Bit Rate (UBR), UBR+, Variable Bit Rate Non Real-Time (VBR-NRT), and real-time Variable Bit Rate (VBR). Only one of these categories can be specified per PVC connection so if a new one is entered, it will replace the existing one.
To configure PVC traffic parameters, use one of the following commands beginning in interface-ATM-VC configuration mode:
| Command | Purpose |
|---|---|
Configure the Available Bit Rate (ABR). (ATM-CES port adapter only.) | |
ubr output-pcr | Configure the Unspecified Bit Rate (UBR). |
Configure the UBR and a minimum guaranteed rate. | |
vbr-nrt output-pcr output-scr output-mbs | Configure the Variable Bit Rate-Non Real Time (VBR-NRT) QOS. |
vbr-rt peak-rate average-rate burst | Configure the real-time Variable Bit Rate (VBR). (Cisco MC3810 only.) |
The -pcr and -mcr arguments are the peak cell rate and minimum cell rate, respectively. The -scr and -mbs arguments are the sustainable cell rate and maximum burst size, respectively.
For an example of how to configure an ABR PVC, refer to the section "Configure an ABR PVC Example" at the end of this chapter.
For a description of how to configure traffic parameters in a VC class and apply the VC class to an ATM interface or subinterface, refer to the section "Configure VC Classes."
For ABR VCs, you can optionally configure the amount that the cell transmission rate increases or decreases in response to flow control information from the network or destination. To configure this option, use the following command in interface-ATM-VC configuration mode:
| Command | Purpose |
|---|---|
abr rate-factors [rate-increase-factor] [rate-decrease-factor] | Specify the ABR rate factors. The default increase and decrease rate factors is 1/16. |
For an example of configuring an ABR PVC, see the section "Configure an ABR PVC Example" later in this chapter.
You can configure your router to automatically discover PVCs that are configured on an attached adjacent switch. The discovered PVCs and their traffic parameters are configured on an ATM main interface or subinterface that you specify. Your router receives the PVC parameter information using Interim Local Management Interface (ILMI).
To configure PVC discovery on an ATM interface, use the following commands beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| interface atm slot/0 or interface atm slot/port-adapter/0 or interface atm number | Specify the ATM interface using the appropriate format of the interface atm command.1 | ||
| pvc [name] 0/16 ilmi | Configure an ILMI PVC on the main interface. | ||
| exit | Return to interface configuration mode. | ||
| Configure PVC Discovery on the main interface and optionally specify that discovered PVCs will be assigned to a subinterface. | |||
| exit | Return to global configuration mode. | ||
| interface atm slot/0[.subinterface-number or interface atm slot/port-adapter/0[.subinterface-number {multipoint | point-to-point}] or interface atm number[.subinterface-number {multipoint | point-to-point}] | Specify the ATM main interface or subinterface that discovered PVCs will be assigned to. | ||
| ip address ip-address mask | (Optional) Specify the protocol address for the subinterface. |
Use the subinterface keyword in Step 4 if you want the discovered PVCs to reside on an ATM subinterface that you specify in Step 6. The discovered PVCs are assigned to the subinterface number that matches the VPI number of the discovered PVC. For example, if subinterface 2/0.1 is specified using the interface atm command in Step 6, then all discovered PVCs with a VPI value of 1 will be assigned to this subinterface. For an example, see the section "Configure PVC Discovery Example" later in this chapter.
Repeat Steps 6 and 7 if you want discovered PVCs to be assigned to more than one subinterface. If no subinterfaces are configured, discovered PVCs will be assigned to the main interface specified in Step 1.
For an example of configuring PVC discovery, refer to the section "Configure PVC Discovery Example" at the end of this chapter.
Inverse ARP is enabled by default when you create a PVC using the pvc command. Once configured, a protocol mapping between an ATM PVC and a network address is learned dynamically as a result of the exchange of ATM Inverse ARP packets.
Inverse ARP is supported on PVCs running IP or IPX and no static map is configured. If a static map is configured, Inverse ARP will be disabled.
To enable Inverse ARP on an ATM PVC, use the following commands beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| interface atm slot/0[.subinterface-number {multipoint | point-to-point}] or interface atm slot/port-adapter/0[.subinterface-number {multipoint | point-to-point}] or interface atm number[.subinterface-number {multipoint | point-to-point}] | Specify the ATM interface using the appropriate format of the interface atm command.1 | ||
| pvc [name] vpi/vci | Specify an ATM PVC by name (optional) and VPI/VCI numbers. | ||
| encapsulation aal5snap | Configure AAL5 LLC-SNAP encapsulation if it is not already configured. | ||
| (Optional) Adjust the Inverse ARP time period. |
When PVC discovery is enabled on an active PVC and the router terminates that PVC, the PVC will generate an ATM Inverse ARP request. This allows the PVC to resolve its own network addresses without configuring a static map.
Address mappings learned through Inverse ARP are aged out. However, mappings are refreshed periodically. This period is configurable using the inarp command which has a default of 15 minutes.
You can also enable Inverse ARP using the protocol command. This is only necessary if you disabled Inverse ARP using the no protocol command. For more information about this command, refer to the "ATM Commands" chapter in the Wide-Area Networking Command Reference.
For an example of configuring Inverse ARP, see the section "Enable Inverse ARP Example" at the end of this chapter.
You can optionally configure the PVC to generate end-to-end F5 OAM loopback cells to verify connectivity on the virtual circuit. The remote end must respond by echoing back such cells. If OAM response cells are missed (indicating the lack of connectivity), the PVC state goes down. If all the PVCs on a subinterface go down, the subinterface goes down.
To configure transmission of end-to-end F5 OAM cells on a PVC, use the following commands in interface-ATM-VC configuration mode:
| Steps | Command | Purpose | ||
|---|---|---|---|---|
| oam-pvc [manage] frequency | Configure transmission of end-to-end F5 OAM loopback cells on a PVC, specify how often loopback cells should be sent, and optionally enable OAM management of the connection. | ||
| oam retry up-count down-count retry-frequency | (Optional) Specify OAM management parameters for verifying connectivity of a PVC connection. This command is only supported if OAM management is enabled. |
Use the up-count argument to specify the number of consecutive end-to-end F5 OAM loopback cell responses that must be received in order to change a PVC connection state to up. Use the down-count argument to specify the number of consecutive end-to-end F5 OAM loopback cell responses that are not received in order to tear down a PVC. Use the retry-frequency argument to specify the frequency (in seconds) that end-to-end F5 OAM loopback cells should be transmitted when a change in UP/DOWN state is being verified. For example, if a PVC is up and a loopback cell response is not received after the frequency (in seconds) specified using the oam-pvc command, then loopback cells are sent at the retry-frequency to verify whether or not the PVC is down.
For information about managing PVCs using OAM, see the section "Configure OAM Management" later in this chapter.
For an example of OAM loopback cell generation, see the section "Configure Generation of End-to-End F5 OAM Loopback Cells Example" at the end of this chapter.
To send duplicate broadcast packets for all protocols configured on a PVC, use the following command in interface-ATM-VC configuration mode:
| Command | Purpose |
|---|---|
Send duplicate broadcast packets for all protocols configured on a PVC. |
By creating a VC class, you can preconfigure a set of default parameters that you may apply to a PVC. To create a VC class, refer to the section "Configure VC Classes" later in this chapter.
Once you have created a VC class, use the following command in interface-ATM-VC configuration mode to apply the VC class to a PVC:
| Command | Purpose |
|---|---|
Apply a VC class to a PVC. |
The vc-class-name is the same as the name you specified when you created a VC class using the vc-class atm command. Refer to the section "Configure VC Classes" later in this chapter for a description of how to create a VC class.
ATM switched virtual circuit (SVC) service operates much like X.25 SVC service, although ATM allows much higher throughput. Virtual circuits are created and released dynamically, providing user bandwidth on demand. This service requires a signaling protocol between the router and the switch.
The ATM signaling software provides a method of dynamically establishing, maintaining, and clearing ATM connections at the User-Network Interface (UNI). The ATM signaling software conforms to ATM Forum UNI 3.0 or ATM Forum UNI 3.1 depending on what version is selected by ILMI or configuration.
In UNI mode, the user is the router and the network is an ATM switch. This is an important distinction. The Cisco router does not perform ATM-level call routing. Instead, the ATM switch does the ATM call routing, and the router routes packets through the resulting circuit. The router is viewed as the user and the LAN interconnection device at the end of the circuit, and the ATM switch is viewed as the network.
Figure 2 illustrates the router position in a basic ATM environment. The router is used primarily to interconnect LANs via an ATM network. The workstation connected directly to the destination ATM switch illustrates that you can connect not only routers to ATM switches, but also any computer with an ATM interface that conforms to the ATM Forum UNI specification.
You must complete the tasks in the following sections to use SVCs:
The tasks in the following sections are optional SVC tasks for customizing your network. These tasks are considered advanced; the default values are almost always adequate. You should not have to perform these tasks unless you need to customize your particular SVC connection.
In an SVC environment, you must configure a PVC for communication with the Integrated Local Management Interface (ILMI) so the router can receive SNMP traps and new network prefixes. The recommended vpi and vci values for the ILMI PVC are 0 and 16, respectively. To configure ILMI communication, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
pvc [name] 0/16 ilmi | Create an ILMI PVC on an ATM main interface. |
Once you have configured an ILMI PVC, you can optionally enable the ILMI keepalive function by using the following command in interface configuration mode:
| Command | Purpose |
Optionally, enable ILMI keepalives and set the interval between keepalives. |
No other configuration steps are required.
ILMI address registration for receipt of SNMP traps and new network prefixes is enabled by default. The ILMI keepalive function is disabled by default; when enabled, the default interval between keepalives is 3 seconds.
For an example of configuring ILMI, see the section "Configure Communication with the ILMI Example" at the end of this chapter.
Unlike X.25 service, which uses in-band signaling (connection establishment done on the same circuit as data transfer), ATM uses out-of-band signaling. One dedicated PVC exists between the router and the ATM switch, over which all SVC call establishment and call termination requests flow. After the call is established, data transfer occurs over the SVC, from router to router. The signaling that accomplishes the call setup and teardown is called Layer 3 signaling or the Q.2931 protocol.
For out-of-band signaling, a signaling PVC must be configured before any SVCs can be set up. Figure 3 illustrates that a signaling PVC from the source router to the ATM switch is used to set up two SVCs. This is a fully meshed network; workstations A, B, and C all can communicate with each other.
To configure the signaling PVC for all SVC connections, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
pvc [name] vpi/vci qsaal | Configure the signaling PVC for an ATM main interface that uses SVCs. |
The VPI and VCI values must be configured consistently with the local switch. The standard value for VPI and VCI are 0 and 5, respectively.
See the section "SVCs in a Fully Meshed Network Example" at the end of this chapter for a sample ATM signaling configuration.
Every ATM interface involved with signaling must be configured with a network service access point (NSAP) address. The NSAP address is the ATM address of the interface and must be unique across the network.
To configure an NSAP address, complete the tasks described in one of the following sections:
If the switch is capable of delivering the NSAP address prefix to the router via ILMI and the router is configured with a PVC for communication with the switch via ILMI, you can configure the endstation ID (ESI) and selector fields using the atm esi-address command. The atm esi-address command allows you to configure the ATM address by entering the ESI (12 hexadecimal characters) and the selector byte (2 hexadecimal characters). The NSAP prefix (26 hexadecimal characters) is provided by the ATM switch.
To configure the router to get the NSAP prefix from the switch and use locally entered values for the remaining fields of the address, use the following commands beginning in interface configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| pvc [name] 0/16 ilmi | Configure an ILMI PVC on an ATM main interface for communicating with the switch via ILMI. | ||
| exit | Return to interface configuration mode. | ||
| Enter the ESI and selector fields of the NSAP address. |
The recommended vpi and vci values for the ILMI PVC are 0 and 16, respectively.
You can also specify a keepalive interval for the ILMI PVC. See the "Configure Communication with the ILMI" section earlier in this chapter for more information.
To see an example of setting up the ILMI PVC and assigning the ESI and selector fields of an NSAP address, go to the section "SVCs with Multipoint Signaling Example" at the end of this chapter.
When you configure the ATM NSAP address manually, you must enter the entire address in hexadecimal format since each digit entered represents a hexadecimal digit. To represent the complete NSAP address, you must enter 40 hexadecimal digits in the following format:
XX.XXXX.XX.XXXXXX.XXXX.XXXX.XXXX.XXXX.XXXX.XXXX.XX
Because the interface has no default NSAP address, you must configure the NSAP address for SVCs. To set the ATM interface's source NSAP address, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Configure the ATM NSAP address for an interface. |
The atm nsap-address and atm esi-address commands are mutually exclusive. Configuring the router with the atm nsap-address command negates the atm esi-address setting, and vice versa. For information about using the atm esi-address command, see the previous section "Configure the ESI and Selector Fields."
See an example of assigning an NSAP address to an ATM interface in the section "ATM NSAP Address Example" at the end of this chapter.
To create an SVC, use the following commands beginning in interface configuration mode:
| Steps | Command | Purpose | ||
|---|---|---|---|---|
| Create an SVC and specify the destination NSAP address. | |||
| (Optional) Configure the ATM adaptation layer (AAL) and encapsulation type. | |||
| Map a protocol address to an SVC. |
Once you specify a name for an SVC, you can re-enter the interface-ATM-VC configuration mode by simply entering svc name; you can remove an SVC configuration by entering no svc name.
For a list of AAL types and encapsulations supported for the aal-encap argument, refer to the encapsulation command in the "ATM Commands" chapter of the Wide-Area Networking Command Reference. The default is AAL5 with SNAP encapsulation.
Normally, when ILMI link autodetermination is enabled on the interface and is successful, the router takes the user-network interface (UNI) version returned by ILMI. If the ILMI link autodetermination process is unsuccessful or ILMI is disabled, the UNI version defaults to 3.0. You can override this default by using the atm uni-version command. The no form of the command sets the UNI version to the one returned by ILMI if ILMI is enabled and the link autodetermination is successful. Otherwise, the UNI version will revert to 3.0. To override the ATM UNI version used by the router, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Override UNI version used by router. |
No other configuration steps are required.
You can specify an interval of inactivity after which any idle SVC on an interface is torn down. This timeout interval might help control costs and free router memory and other resources for other uses.
To change the idle timeout interval, use the following command in interface-ATM-VC configuration mode:
| Command | Purpose |
|---|---|
Configure the interval of inactivity after which an idle SVC will be torn down. |
In addition to configuring the interval of inactivity, you can optionally specify the minimum-rate in kilobits per second (Kbps). This is the minimum traffic rate required on an ATM SVC to maintain the connection.
Point-to-multipoint signaling (or multicasting) allows the router to send one packet to the ATM switch and have the switch replicate the packet to the destinations. It replaces pseudobroadcasting on specified virtual circuits for protocols configured for broadcasting.
You can configure multipoint signaling on an ATM interface after you have mapped protocol addresses to NSAPs and configured one or more protocols for broadcasting.
After multipoint signaling is set, the router uses the SVC configurations that have the broadcast keyword set to establish multipoint calls. The call is established to the first destination with a Setup message. Additional parties are added to the call with AddParty messages each time a multicast packet is sent. One multipoint call will be established for each logical subnet of each protocol that has the broadcast keyword set.
To configure multipoint signaling on an ATM interface, use the following commands beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| interface atm slot/0 or interface atm slot/port-adapter/0 or interface atm number | Specify the ATM interface using the appropriate format of the interface atm command.1 | ||
| pvc [name] 0/5 qsaal | Configure the signaling PVC for an ATM main interface that uses SVCs. | ||
| exit | Return to interface configuration mode. | ||
| pvc [name] 0/16 ilmi and exit | (Optional) Configure an ILMI PVC on an ATM main interface and return to interface configuration mode. This task is required if you configure the ATM NSAP address in Step 5 by configuring the ESI and selector fields. | ||
|
| Configure the complete NSAP address manually. or Configure the ESI and selector fields. To use this method, you must configure Step 4 first. | ||
| Create an SVC and specify the destination NSAP address. Enter interface-ATM-VC mode. | |||
| Provide a protocol address for the interface and enable broadcasting. | |||
| exit | Return to interface configuration mode. | ||
| Enable multipoint signaling to the ATM switch. | |||
| (Optional) Limit the frequency of sending AddParty messages. |
If multipoint virtual circuits are closed, they are reopened with the next multicast packet. Once the call is established, additional parties are added to the call when additional multicast packets are sent. If a destination never comes up, the router constantly attempts to add it to the call by means of multipoint signaling.
For an example of configuring multipoint signaling on an interface that is configured for SVCs, see the section "SVCs with Multipoint Signaling Example" at the end of this chapter.
This task is documented in the "Configuring IP Multicast Routing" chapter of the Network Protocols Configuration Guide, Part 1.
The tasks in this section are optional and advanced. The ATM signaling software can specify to the ATM interface on the router and the switch a limit on how much traffic the source router will be sending. It provides this information in the form of traffic parameters. (These parameters have default values.) The ATM switch in turn sends these values as requested by the source to the ATM destination node. If the destination cannot provide such capacity levels, the call may fail. (For Cisco router series behavior, see the per-interface atm sig-traffic-shaping strict command in the Wide-Area Networking Command Reference.) There is a single attempt to match traffic values.
The supported traffic parameters are part of the following service categories: Unspecified Bit Rate (UBR), UBR+, and Variable Bit Rate Non Real-Time (VBR-NRT). Only one of these categories can be specified per SVC connection so if a new one is entered, it will replace the existing one. The commands used to specify the service category and traffic values are identical to those used when you create a PVC.
To configure traffic parameters on an SVC, use the following commands beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| interface atm slot/0[.subinterface-number or interface atm slot/port-adapter/0[.subinterface-number {multipoint | point-to-point}] or interface atm number[.subinterface-number {multipoint | point-to-point}] | Specify the ATM interface using the appropriate format of the interface atm command.1 | ||
| Create an SVC and specify the destination NSAP address. | |||
| Map a destination protocol address to an SVC. | |||
|
ubr+ output-pcr output-mcr [input-pcr] [input-mcr] or vbr-nrt output-pcr output-scr output-mbs [input-pcr] [input-scr] [input-mbs] | Configure the Unspecified Bit Rate (UBR) or Configure the UBR and a minimum guaranteed rate or Configure the Variable Bit Rate-Non Real Time (VBR-NRT) QOS | ||
| exit | Return to interface configuration mode and enable the traffic parameters on the SVC. |
The -pcr and -mcr arguments are the peak cell rate and minimum cell rate, respectively. The -scr and -mbs arguments are the sustainable cell rate and maximum burst size, respectively.
For an example of configuring traffic parameters on an SVC, see the section "Configure SVC Traffic Parameters Example" at the end of this chapter.
For a description of how to configure traffic parameters in a VC class and apply the VC class to an ATM interface or subinterface, refer to the section "Configure VC Classes."
You can configure strict traffic shaping on an ATM interface to specify that an SVC be established using only signaled traffic parameters. If such shaping cannot be provided, the SVC is released.
To specify that an SVC be established on an ATM interface using only signaled traffic parameters, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Specify that an SVC be established on an ATM interface using only signaled traffic parameters. |
If you do not configure strict traffic shaping on the router ATM interface, an attempt is made to establish an SVC with traffic shaping for the transmit cell flow per the signaled traffic parameters. If such shaping cannot be provided, the SVC is installed with default shaping parameters; that is, it behaves as though a PVC were created without specifying traffic parameters.
You can optionally configure the SVC to generate end-to-end F5 OAM loopback cells to verify connectivity on the virtual circuit. The remote end must respond by echoing back such cells. If OAM response cells are missed (indicating the lack of connectivity), the SVC is torn down. For more information, refer to the "Configure OAM Management" section later in this chapter.
To configure transmission of end-to-end F5 OAM loopback cells on an SVC, use the following commands in interface-ATM-VC configuration mode:
| Steps | Command | Purpose | ||
|---|---|---|---|---|
| Configure transmission of end-to-end F5 OAM loopback cells on an SVC, specify how often loopback cells should be sent, and optionally enable OAM management of the connection. | |||
| (Optional) Specify OAM management parameters for verifying connectivity of an SVC connection. This command is only supported if OAM management is enabled. |
The up-count argument does not apply to SVCs, but it must be specified in order to configure the down-count and retry-frequency. Use the down-count argument to specify the number of consecutive end-to-end F5 OAM loopback cell responses that are not received in order to tear down an SVC. Use the retry-frequency argument to specify the frequency (in seconds) that end-to-end F5 OAM loopback cells should be transmitted when a change in UP/DOWN state is being verified. For example, if an SVC is up and a loopback cell response is not received after the frequency (in seconds) specified using the oam-svc command, then loopback cells are sent at the retry-frequency to verify whether or not the SVC is down.
To send duplicate broadcast packets or send a single broadcast packet using multipoint signaling for all protocols configured on an SVC, use the following command in interface-ATM-VC configuration mode:
| Command | Purpose |
|---|---|
Send duplicate broadcast packets for all protocols configured on an SVC. |
By creating a VC class, you can preconfigure a set of default parameters that you may apply to an SVC. To create a VC class, refer to the section "Configure VC Classes" later in this chapter.
Once you have created a VC class, use the following command in interface-ATM-VC configuration mode to apply the VC class to an SVC:
| Command | Purpose |
|---|---|
Apply a VC class to an SVC. |
The vc-class-name is the same as the name you specified when you created a VC class using the vc-class atm command. Refer to the section "Configure VC Classes" later in this chapter for a description of how to create a VC class.
The Service-Specific Connection-Oriented Protocol (SSCOP) resides in the service-specific convergence sublayer (SSCS) of the ATM adaptation layer (AAL). SSCOP is used to transfer variable-length service data units (SDUs) between users of SSCOP. SSCOP provides for the recovery of lost or corrupted SDUs.
The poll timer controls the maximum time between transmission of a POLL PDU when sequential data (SD) or SDP PDUs are queued for transmission or are outstanding pending acknowledgments. To change the poll timer from the default value of 100 seconds, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Set the poll timer. |
The keepalive timer controls the maximum time between transmission of a POLL PDU when no SD or SDP PDUs are queued for transmission or are outstanding pending acknowledgments. To change the keepalive timer from the default value of 5 seconds, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Set the keepalive timer. |
The connection control timer determines the time between transmission of BGN, END, or RS (resynchronization) PDUs as long as an acknowledgment has not been received. Connection control performs the establishment, release, and resynchronization of an SSCOP connection.
To change the connection control timer from the default value of 1 seconds, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Set the connection control timer. |
To change the retry count of the connection control timer from the default value of 10, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Set the number of times that SSCOP will retry to transmit BGN, END, or RS PDUs when they have not been acknowledged. |
A transmitter window controls how many packets can be transmitted before an acknowledgment is required. To change the transmitter's window from the default value of 7, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Set the transmitter's window. |
A receiver window controls how many packets can be received before an acknowledgment is required. To change the receiver's window from the default value of 7, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Set the receiver's window. |
You can disconnect an idle SVC by using the following command in EXEC mode:
| Command | Purpose |
|---|---|
Close the signaling PVC for an SVC. |
A VC class is a set of preconfigured VC parameters that you configure and apply to a particular VC or ATM interface. You may apply a VC class to an ATM main interface, subinterface, PVC or SVC. For example, you can create a VC class that contains VC parameter configurations that you will apply to a particular PVC or SVC. You might create another VC class that contains VC parameter configurations that you will apply to all VCs configured on a particular ATM main interface or subinterface. Refer to the "ATM Configuration Examples" section later in this chapter for examples of VC class configurations.
To create and use a VC class, complete the following tasks:
To create a VC class, use the following command in global configuration mode:
| Command | Purpose |
|---|---|
vc-class atm name | Create a VC class and enter vc-class configuration mode. |
For examples of creating VC classes, see the section "Create a VC Class Examples" at the end of this chapter.
After you create a VC class and enter vc-class configuration mode, configure VC parameters using one or more of the following commands:
Refer to the sections "Configure PVCs" and "Configure SVCs" for descriptions on how to configure these commands for PVCs and SVCs.
If an SVC command (for example, idle-timeout or oam-svc) is configured in a VC class, but the VC class is applied on a PVC, the SVC command is ignored. This is also true if a PVC command is applied to an SVC.
For examples of creating VC classes, see the section "Create a VC Class Examples" at the end of this chapter.
Once you have created and configured a VC class, you can apply it directly on an ATM PVC or SVC, or you can apply it on an ATM interface or subinterface.
To apply a VC class directly on an ATM PVC or SVC, use the following commands beginning in interface configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| pvc [name] vpi/vci or svc [name] nsap address | Specify an ATM PVC or Specify an ATM SVC | ||
| Apply a VC class directly on the PVC or SVC. |
To apply a VC class on an ATM main interface or subinterface, use the following commands beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| interface atm slot/0[.subinterface-number {multipoint | point-to-point}] or interface atm slot/port-adapter/0[.subinterface-number {multipoint | point-to-point}] or interface atm number[.subinterface-number | Specify the ATM interface using the appropriate format of the interface atm command.1 | ||
| Apply a VC class on an the ATM main interface or subinterface. |
For examples of applying a VC class to an ATM interface, see the section "Apply a VC Class Examples" later in this chapter.
When you configure VC management, you enable the router to detect VC connections and disconnections automatically. This notifies protocols to reroute packets immediately, preventing protocols from waiting for unpredictable and relatively long timeout periods.
You may use Integrated Local Management Interface (ILMI) or Operation, Administration, and Maintenance (OAM) or both for managing your PVCs, and OAM for managing your SVCs. For PVCs, you must decide which method is reliable in your particular network.
When ILMI and OAM management methods are both configured to manage a PVC, both must indicate that a PVC is up in order for that PVC to be determined as up. If either ILMI or OAM is not configured, a PVC will be managed by the method that is configured.
When a PVC goes down, route caches for protocols configured on that PVC are cleared (or flushed) so that new routes may be learned. The route cache flush is applied on the PVC's interface. When all PVCs on a subinterface go down, VC management shuts down the subinterface in addition to flushing route caches. ATM hardware must keep the PVC active, however, so that OAM and ILMI cells may flow. When any PVC on a subinterface comes up, the subinterface is brought up.
VC management using ILMI is referred to as ILMI management. VC management using OAM is referred to as OAM management. To configure either management method or both, perform the tasks in one or both of the following sections:
ILMI management applies to PVCs only. To configure ILMI management, use the following commands beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| interface atm slot/0[.subinterface-number or interface atm slot/port-adapter/0[.subinterface-number {multipoint | point-to-point}] or interface atm number[.subinterface-number {multipoint | point-to-point}] | Specify the ATM interface using the appropriate format of the interface atm command.1 | ||
| pvc [name] 0/16 ilmi | Configure a PVC for communication with the ILMI. | ||
| interface atm slot/0.subinterface-number multipoint or interface atm slot/port-adapter/0.subinterface-number multipoint or interface atm number.subinterface-number multipoint | (Optional) Specify the ATM subinterface of the PVC you want to manage. | ||
| pvc [name] vpi/vci | Specify the PVC to be managed. | ||
| Enable ILMI management on the PVC. |
Repeat Steps 4 and 5 for each PVC you want to manage. Step 3 is only necessary if you wish to configure a PVC on a subinterface and not just on the main ATM interface.
The PVC comes up only if ILMI indicates the PVC is up. The PVC comes down when ILMI indicates that the PVC is down. If OAM management is also configured for the same PVC, the PVC comes up only if both ILMI and OAM indicate that the PVC is up.
For an example of configuring ILMI management on a PVC, see the section "ILMI Management on an ATM PVC Example" at the end of this chapter.
OAM management may be enabled for both PVCs and SVCs. To configure OAM management, configure the tasks in one or both of the following sections:
To configure OAM management for an ATM PVC, use the following commands beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| interface atm slot/0[.subinterface-number {multipoint | point-to-point}] or interface atm slot/port-adapter/0[.subinterface-number {multipoint | point-to-point}] or interface atm number[.subinterface-number {multipoint | point-to-point}] | Specify the ATM interface using the appropriate format of the interface atm command.1 | ||
| pvc [name] vpi/vci | Specify the ATM PVC. | ||
| oam-pvc manage [frequency] | Enable OAM management on the PVC. | ||
| (Optional) Specify OAM management parameters for re-establishing and removing a PVC connection. |
Use the up-count argument to specify the number of consecutive end-to-end F5 OAM loopback cell responses that must be received in order to change a PVC connection state to up. Use the down-count argument to specify the number of consecutive end-to-end F5 OAM loopback cell responses that are not received in order to tear down a PVC. Use the retry-frequency argument to specify the frequency (in seconds) that end-to-end F5 OAM loopback cells should be transmitted when a change in UP/DOWN state is being verified. For example, if a PVC is up and a loopback cell response is not received after the frequency (in seconds) specified using the oam-pvc command, then loopback cells are sent at the retry-frequency to verify whether or not the PVC is down.
By default, end-to-end F5 OAM loopback cell generation is turned off for each PVC. A PVC is determined as down when any of the following is true on that PVC:
A PVC is determined as up when all of the following are true on that PVC:
For an example of configuring OAM management on a PVC, see the section "OAM Management on an ATM PVC Example" at the end of this chapter.
| Step | Command | Purpose | ||
|---|---|---|---|---|
| interface atm slot/0[.subinterface-number {multipoint | point-to-point}] or interface atm slot/port-adapter/0[.subinterface-number {multipoint | point-to-point}] or interface atm number[.subinterface-number {multipoint | point-to-point}] | Specify the ATM interface using the appropriate format of the interface atm command.1 | ||
| svc [name] nsap address | Specify the ATM SVC. | ||
| oam-svc manage [frequency] | Enable OAM management on the SVC. | ||
| (Optional) Specify OAM management parameters for re-establishing and removing an SVC connection. |
If OAM management is enabled on SVCs and detects disconnection on an SVC, that SVC is torn down.
The up-count argument does not apply to SVCs, but it must be specified in order to configure the down-count and retry-frequency. Use the down-count argument to specify the number of consecutive end-to-end F5 OAM loopback cell responses that are not received in order to tear down an SVC. Use the retry-frequency argument to specify the frequency (in seconds) that end-to-end F5 OAM loopback cells should be transmitted when a change in UP/DOWN state is being verified. For example, if an SVC is up and a loopback cell response is not received after the frequency (in seconds) specified using the oam-svc command, then loopback cells are sent at the retry-frequency to verify whether or not the SVC is down.
For an example of configuring OAM management on an SVC, see the section "OAM Management on an ATM SVC Example" at the end of this chapter.
Cisco implements both the ATM Address Resolution Protocol (ARP) server and ATM ARP client functions described in RFC 1577. RFC 1577 models an ATM network as a logical IP subnetwork on a LAN.
The tasks required to configure classical IP and ARP over ATM depend on whether the environment uses SVCs or PVCs.
The ATM ARP mechanism is applicable to networks that use SVCs. It requires a network administrator to configure only the device's own ATM address and that of a single ATM ARP server into each client device. When the client makes a connection to the ATM ARP server, the server sends ATM Inverse ARP requests to learn the IP network address and ATM address of the client on the network. It uses the addresses to resolve future ATM ARP requests from clients. Static configuration of the server is not required or needed.
In Cisco's implementation, the ATM ARP client tries to maintain a connection to the ATM ARP server. The ATM ARP server can tear down the connection, but the client attempts once each minute to bring the connection back up. No error messages are generated for a failed connection, but the client will not route packets until the ATM ARP server is connected and translates IP network addresses.
For each packet with an unknown IP address, the client sends an ATM ARP request to the server. Until that address is resolved, any IP packet routed to the ATM interface will cause the client to send another ATM ARP request. When the ARP server responds, the client opens a connection to the new destination so that any additional packets can be routed to it.
Cisco routers may be configured as ATM ARP clients to work with any ATM ARP server conforming to RFC 1577. Alternatively, one of the Cisco routers in a logical IP subnet (LIS) may be configured to act as the ATM ARP server itself. In this case, it automatically acts as a client as well. To configure classical IP and ARP in an SVC environment, perform the tasks in one of the following sections:
In an SVC environment, configure the ATM ARP mechanism on the interface by using the following commands beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| interface atm slot/0 or interface atm slot/port-adapter/0 or interface atm number | Specify the ATM interface using the appropriate format of the interface atm command.1 | ||
| atm esi-address esi.selector | Specify the ATM address of the interface. | ||
| ip address address mask | Specify the IP address of the interface. | ||
|
|
| ||
|
|
| ||
| Specify the ATM address of the ATM ARP server. | |||
| no shutdown | Enable the ATM interface. |
You can designate the current router interface as the ATM ARP server in Step 4 by typing self in place of nsap nsap-address.
To configure the ESI and selector fields in Step 2, the switch must be capable of delivering the NSAP address prefix to the router via ILMI and the router must be configured with a PVC for communication with the switch via ILMI. For a description of how to configure an ILMI PVC, refer to the section "Configure Communication with the ILMI" earlier in this chapter.
For an example of configuring the ATM ARP client, see the section "ATM ARP Client Configuration in an SVC Environment Example" at the end of this chapter.
Cisco's implementation of the ATM ARP server supports a single, nonredundant server per logical IP subnetwork (LIS) and supports one ATM ARP server per subinterface. Thus, a single card can support multiple ARP servers by using multiple subinterfaces.
To configure the ATM ARP server, use the following commands beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| interface atm slot/0 or interface atm slot/port-adapter/0 or interface atm number | Specify the ATM interface using the appropriate format of the interface atm command.1 | ||
| atm esi-address esi.selector | Specify the ATM address of the interface. | ||
| ip address ip-address mask | Specify the IP address of the interface. | ||
| Identify the ATM ARP server for the IP subnetwork network. | |||
| no shutdown | Enable the ATM interface. |
To configure the ESI and selector fields in Step 2, the switch must be capable of delivering the NSAP address prefix to the router via ILMI and the router must be configured with a PVC for communication with the switch via ILMI. For a description of how to configure an ILMI PVC, refer to the section "Configure Communication with the ILMI" earlier in this chapter.
For an example of configuring the ATM ARP server, see the section "ATM ARP Server Configuration in an SVC Environment Example" at the end of this chapter.
The ATM Inverse ARP mechanism is applicable to networks that use PVCs, where connections are established but the network addresses of the remote ends are not known. A server function is not used in this mode of operation.
In a PVC environment, the ATM Inverse ARP mechanism is enabled by default for IP and IPX when you use the following commands beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| interface atm slot/0 or interface atm slot/port-adapter/0 or interface atm number | Specify the ATM interface using the appropriate format of the interface atm command.1 | ||
| ip address ip-address mask | Specify the IP address of the interface. | ||
| pvc [name] vpi/vci | |||
| no shutdown | Enable the ATM interface. |
Repeat Step 3 for each PVC you want to create.
By default, Inverse ARP datagrams will be sent on this virtual circuit every 15 minutes. To adjust the Inverse ARP time period, use the inarp minutes command in interface-ATM-VC configuration mode.
For an example of configuring the ATM Inverse ARP mechanism, see the section "ATM Inverse ARP Configuration in a PVC Environment Example" at the end of this chapter.
You can customize the ATM interface. The features you can customize have default values that will most likely suit your environment and probably need not be changed. However, you might need to enter configuration commands, depending upon the requirements for your system configuration and the protocols you plan to route on the interface. Perform the tasks in the following sections if you need to customize the ATM interface:
A rate queue defines the speed at which individual virtual circuits will transmit data to the remote end. You can configure permanent rate queues, allow the software to set up dynamic rate queues, or perform some combination of the two. The software dynamically creates rate queues when you create a VC with a peak rate that does not match any user-configured rate queue. The software dynamically creates all rate queues if you have not configured any.
The Cisco IOS software automatically creates rate queues as necessary when you create a VC. If you do not configure traffic shaping on a VC, the peak rate of the VC is set to the UBR at the maximum peak rate that the physical layer interface module (PLIM) will allow. A rate queue is then dynamically created for the peak rate of that VC.
If dynamic rate queues do not satisfy your traffic shaping needs, you can configure permanent rate queues. Refer to the section "Configure a Permanent Rate Queue" for more information.
See the "Dynamic Rate Queue Examples" section for example configurations of different rate queues.
To improve rate queue usage, you can configure a peak cell rate tolerance range for dynamically created rate queues. A PVC or SVC requesting a particular rate queue speed will be assigned to a rate queue that is within the range of the peak cell rate tolerance. If no such rate queue exists, a new rate queue is dynamically created on the ATM interface.
To configure a rate queue tolerance range for VCs on an ATM interface, use the following commands beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| interface atm slot/0 or interface atm slot/port-adapter/0 or interface atm number | Specify the ATM interface using the appropriate format of the interface atm command.1 | ||
| Configure a rate queue tolerance. |
The tolerance-value is expressed as a percentage used for assigning rate queues for each VC with a requested peak rate. This value is applied to SVCs, discovered VCs, and PVCs (when the pvc keyword is used). This value can be 0 or 5 through 99. For SVCs and discovered VCs, the default value is 10. If the pvc keyword is not specified, the rate queue tolerance for PVCs will default to 0.
The supports up to eight different peak rates. The peak rate is the maximum rate, in kilobits per second, at which a virtual circuit can transmit. Once attached to this rate queue, the virtual circuit is assumed to have its peak rate set to that of the rate queue. The rate queues are broken into a high-priority (0 through 3) and low-priority (4 through 7) bank.
You can configure each permanent rate queue independently to a portion of the overall bandwidth available on the ATM link. The combined bandwidths of all rate queues should not exceed the total bandwidth available. The total bandwidth depends on the PLIM (see the "Interface Types" section in the "Wide-Area Networking Overview" chapter.)
To set a permanent rate queue, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Configure a permanent rate queue, which defines the maximum speed at which an individual virtual circuit transmits data to a remote ATM host. |
Each interface has a default maximum packet size or maximum transmission unit (MTU) size. For ATM interfaces, this number defaults to 4470 bytes. The maximum is 9188 bytes for the AIP and NPM, 17969 for the ATM port adapter, and 17998 for the ATM-CES port adapter. The MTU can be set on a per-sub-interface basis as long as the interface MTU is as large or larger than the largest subinterface MTU. To set the maximum MTU size, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Set the maximum MTU size. |
The default SONET PLIM is STS-3C. To set the SONET PLIM to STM-1 or to set the PLIM framing for E3 or DS3, use one of the following commands in interface configuration mode:
| Command | Purpose |
|---|---|
Set the OC-3c SONET PLIM to STM-1. | |
Set DS3 framing mode. | |
atm framing [g751adm | g832 adm | g751plcp] | Set E3 framing mode. |
The default for DS3 is C-Bit ADM framing; the default for E3 is G.751 with PLCP framing.
To loop all packets back to the instead of the network, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Set loopback mode. |
To loop the incoming network packets back to the ATM network, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Set line loopback mode. |
The exception queue is used for reporting ATM events, such as CRC errors. By default, it holds 32 entries; the range is 8 to 256. It is unlikely you will need to configure the exception queue length; if you do, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Set the exception queue length. |
The atm max-channels command can be used to divide the available number (fixed) of transmit descriptors across the configured number of transmit channels. Typically, you think of a one-to-one association between a transmit channel and a VC; however, the ATM-CES port adapter supports types of VCs other than data VCs (for example CES VCs). Also, the ATM-CES port adapter can multiplex one or more VCs over a single virtual path (VP) that is shaped, and the VP only requires a single transmit channel. Therefore, the term transmit channel is used rather than virtual circuit.
The maximum burst of packets that are allowed per VC is limited by the number of transmit descriptors allocated per VC. Because the total number of transmit descriptors available is limited by the available SRAM space, configuration of the number of transmit channels for the interface determines the number of transmit descriptors for each transmit channel. Hence the burst size for each transmit channel is determined by the atm max-channels command. For example, for 64 (default) numbers of transmit channels for the interface, 255 transmit descriptors are associated per transmit channel and for 512 numbers of transmit channels for the interface, 31 transmit descriptors are associated per transmit channel.
To configure the maximum number of transmit channels for the interface, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Configure the maximum number of transmit channels. |
By default, the ATM interface allows the maximum of 2048 virtual circuits. However, you can configure a lower number, thereby limiting the number of virtual circuits on which the allows segmentation and reassembly to occur. Limiting the number of virtual circuits does not affect the VPI-VCI pair of each virtual circuit.
To set the maximum number of virtual circuits supported (including PVCs and SVCs), use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Limit the number of virtual circuits. |
The raw queue is used for raw ATM cells, which include Operation, Administration, and Maintenance (OAM) and Interim Local Management Interface (ILMI) cells. ILMI is a means of passing information to the router, including information about virtual connections and addresses.
The raw-queue size is in the range of 8 to 256 cells; the default is 32 cells. To set the raw-queue size, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Set the raw-queue size. |
The number of receive buffers determines the maximum number of reassemblies that the can perform simultaneously. The number of buffers defaults to 256, although it can be in the range from 0 to 512. To set the number of receive buffers, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Set the number of receive buffers. |
The number of transmit buffers determines the maximum number of fragmentations that the can perform simultaneously. The number of buffers defaults to 256, although it can be in the range from 0 to 512. To set the number of transmit buffers, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Set the number of transmit buffers. |
By default, the supports 1024 VCIs per VPI. This value can be any power of 2 in the range from 16 to 1024. This value controls the memory allocation on the to deal with the VCI table. It defines only the maximum number of VCIs to support per VPI.
To set the maximum number of VCIs to support per VPI and limit the highest VCI accordingly, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Set the number of VCIs per VPI. |
By default, the expects the ATM switch to provide transmit clocking. To specify that the generate the transmit clock internally for SONET and E3 PLIM operation, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Specify that the generate the transmit clock internally. |
An ATM adaptation layer (AAL) defines the conversion of user information into cells by segmenting upper-layer information into cells at the transmitter and reassembling them at the receiver. AAL1 and AAL2 handle isochronous traffic, such as voice and video, and are not relevant to the router. AAL3/4 and AAL5 support data communications by segmenting and reassembling packets. Beginning in Cisco IOS Release 10.2, we support both AAL3/4 and AAL5.
Our implementation of the AAL3/4 encapsulates each AAL3/4 packet in a Switched Multimegabit Data Service (SMDS) header and trailer. This feature supports both unicast and multicast addressing, and provides subinterfaces for multiple AAL3/4 connections over the same physical interface.
Support for AAL3/4 on an ATM interface requires static mapping of all protocols except IP. However, dynamic routing of IP can coexist with static mapping of other protocols on the same ATM interface.
To configure an ATM interface for SMDS networks, use the following commands in interface configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| Enable AAL3/4 support on the affected ATM subinterface. | |||
| atm smds-address address | Provide an SMDS E.164 unicast address for the subinterface. | ||
| atm multicast address | Provide an SMDS E.164 multicast address. | ||
| Configure a virtual path filter for the affected ATM subinterface. | |||
| pvc [name] vpi/vci smds | Create an AAL3/4 PVC. |
The virtual path filter provides a mechanism for specifying which VPIs (or a range of VPIs) will be used for AAL3/4 processing during datagram reassembly. All other VPIs are mapped to AAL5 processing. For more information about the way the atm vp-filter command works and the effect of selecting specific values, refer to the Wide-Area Networking Command Reference.
After configuring the ATM interface for SMDS networks, configure the interface for standard protocol configurations, as needed. For more information about protocol configuration, refer to the relevant chapters of the Network Protocols Configuration Guide, Part 1, the Network Protocols Configuration Guide, Part 2, and the Network Protocols Configuration Guide, Part 3.
For examples of configuring an ATM interface for AAL3/4 support, see the section "PVC with AAL3/4 and SMDS Encapsulation Examples" at the end of this chapter.
Message identifier (MID) numbers are used by receiving devices to reassemble cells from multiple sources into packets.
To ensure that the message identifiers are unique at the receiving end and, therefore, that messages can be reassembled correctly, you can limit the number of message identifiers allowed on a virtual circuit and assign different ranges of message identifiers to different PVCs.
To limit the number of message identifier numbers allowed on each virtual circuit and to assign different ranges of message identifiers to different PVCs, use the following commands beginning in interface configuration mode:
| Steps | Command | Purpose | ||
|---|---|---|---|---|
| Limit the number of message identifiers allowed per virtual circuit. | |||
| pvc [name] vpi/vci smds | Create an ATM PVC with SMDS encapsulation. | ||
| Limit the range of message identifier values used on the PVC. |
The maximum number of message identifiers per virtual circuit is set at 16 by default; valid values are 16, 32, 64, 128, 256, 512, or 1024.
The default value for both midlow and midhigh is zero.
The virtual path filter allows you to specify which VPI or range of VPIs will be used for AAL3/4 processing. The default value of the's virtual path filter register is 0x7B. To set the virtual path filter register, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Set the virtual path filter register. |
Our implementation of transparent bridging over ATM allows the spanning tree for an interface to support virtual circuit descriptors (VCDs) for AAL5-LLC Subnetwork Access Protocol (SNAP) encapsulations.
If the relevant interface or subinterface is explicitly put into a bridge group, as described in the task table below, AAL5-SNAP encapsulated bridge packets on a PVC are fast-switched.
Our bridging implementation supports IEEE 802.3 frame formats and IEEE 802.10 frame formats. The router can accept IEEE 802.3 frames with or without frame check sequence (FCS). When the router receives frames with FCS (RFC 1483 bridge frame formats with 0x0001 in the PID field of the SNAP header), it strips off the FCS and forwards the frame as necessary. All IEEE 802.3 frames that originate at or are forwarded by the router are sent as 802.3 bridge frames without FCS (bridge frame formats with 0x0007 in the PID field of the SNAP header).
To configure transparent bridging for LLC/SNAP PVCs, use the following commands beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| interface atm slot/0[.subinterface-number {multipoint | point-to-point}] or interface atm slot/port-adapter/0[.subinterface-number {multipoint | point-to-point}] or interface atm number[.subinterface-number {multipoint | point-to-point}] | Specify the ATM interface using the appropriate format of the interface atm command.1 | ||
| pvc [name] vpi/vci | Create one or more PVCs using AAL5-SNAP encapsulation. Repeat these command as needed. | ||
| exit | Return to interface configuration mode. | ||
| Assign the interface to a bridge group. | |||
| exit | Return to global configuration mode. | ||
| Define the type of spanning tree protocol as DEC. |
No other configuration is required. Spanning tree updates are broadcast to all AAL5-SNAP virtual circuits that exist on the ATM interface. Only the AAL5-SNAP virtual circuits on the specific subinterface receive the updates. The router does not send spanning tree updates to AAL5-MUX and AAL5-NLPID virtual circuits.
For an example of transparent bridging for an AAL5-SNAP PVC, see the section "Transparent Bridging on an AAL5-SNAP PVC Example" at the end of this chapter.
This section describes how to configure remote Point-to-Point Protocol (PPP) connections.
Before configuring PPP over ATM, the Cisco 7500 series routers must be equipped with Cisco IOS Release 11.2(4)F or later software. Remote branch offices must have PPP configured on PPP-compatible devices interconnecting directly to Cisco StrataCom's ATM Switch Interface Shelf (AXIS) equipment through a leased-line connection. The shelves provide frame forwarding encapsulation and are terminated on BPX cores prior to connecting to a Cisco 7500 series router. Figure 4 shows a typical scenario for using PPP over ATM.
When you configure PPP over ATM, a logical interface known as a virtual access interface associates each PPP connection to an ATM permanent virtual circuit (PVC). You can create this logical interface by configuring an ATM PVC as described in the "Create a PPP-over-ATM PVC" section. This configuration encapsulates each PPP connection in a separate PVC, allowing each PPP connection to terminate at the router ATM interface as if received from a typical PPP serial interface.
The virtual access interface for each PVC obtains its configuration from a virtual interface template (virtual template) when the PVC is created. Before creating the ATM PVC, we suggest you create and configure a virtual template as described in the "Create and Configure a Virtual Template" section.
To configure PPP over ATM, complete the tasks in the following sections. The first task is optional but recommended. The remaining tasks are required.
See an example of configuring PPP over ATM in the section "PPP-over-ATM Example" at the end of this chapter.
Prior to configuring the ATM PVC for PPP over ATM, you typically create and configure a virtual template. To create and configure a virtual template, use the following commands beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| Create a virtual template, and enter interface configuration mode. | |||
| Enable PPP encapsulation on the virtual template. | |||
| Optionally, enable IP without assigning a specific IP address on the LAN. |
Other optional configuration commands can be added to the virtual template configuration. For example, you can enable the PPP authentication on the virtual template using the ppp authentication chap command. Refer to the "Virtual Interface Template Service" chapter in the Dial Solutions Configuration Guide for additional information about configuring the virtual template.
All PPP parameters are managed within the virtual template configuration. Configuration changes made to the virtual template are automatically propagated to the individual virtual access interfaces. Multiple virtual access interfaces can spawn from a single virtual template; hence, multiple PVCs can use a single virtual template.
Cisco IOS software supports up to 25 virtual template configurations. If greater numbers of tailored configurations are required, an authentication, authorization, and accounting (AAA) server may be employed. Refer to the "Per-User Configuration" chapter in the Dial Solutions Configuration Guide for further information on configuring an AAA server.
If the parameters of the virtual template are not explicitly defined before configuring the ATM PVC, the PPP interface is brought up using default values from the virtual template identified. Some parameters (such as an IP address) take effect only if specified before the PPP interface comes up. Therefore, it is recommended that you explicitly create and configure the virtual template before configuring the ATM PVC to ensure such parameters take effect. Alternatively, if parameters are specified after the ATM PVC has already been configured, you should issue a shutdown command followed by a no shutdown command on the ATM subinterface to restart the interface; this restart will cause the newly configured parameters (such as an IP address) to take effect.
Network addresses for the PPP-over-ATM connections are not configured on the main ATM interface or subinterface. Instead, these are configured on the appropriate virtual template or obtained via AAA.
The virtual templates support all standard PPP configuration commands; however, not all configurations are supported by the PPP-over-ATM virtual access interfaces. These restrictions are enforced at the time the virtual template configuration is applied (cloned) to the virtual access interface. These restrictions are described in the following paragraphs.
Only standard first-in, first-out (FIFO) queuing is supported when applied to PPP-over-ATM virtual access interfaces. Other types of queuing which are typically configured on the main interface are not (for example, fair-queuing). If configured, these configuration lines are ignored when applied to a PPP-over-ATM interface.
While fast switching is supported, flow and optimum switching are not; these configurations are ignored on the PPP-over-ATM virtual access interface. Fast switching is enabled by default for the virtual template configuration. If fast switching is not desired, use the no ip route-cache command to disable it.
The PPP reliable link that uses Link Access Procedure, Balanced (LAPB) is not supported.
Because an ATM PVC is configured for this feature, the following standard PPP features are not applicable and should not be configured:
After you create a virtual template for PPP over ATM, you must specify a point-to-point subinterface per PVC connection. To specify an ATM point-to-point subinterface, use one of the following commands in global configuration mode:
| Command | Purpose |
|---|---|
interface atm slot/0.subinterface-number point-to-point or interface atm number.subinterface-number point-to-point | Specify the ATM point-to-point subinterface using the appropriate format of the interface atm command.1 |
After you create a virtual template and specify a point-to-point subinterfaces for PPP over ATM, you must create a PPP-over-ATM PVC. To create a PPP-over-ATM PVC, use the following commands beginning in interface configuration mode:
| Steps | Command | Purpose | ||
|---|---|---|---|---|
| pvc [name] vpi/vci | Create a PVC for PPP-over-ATM. | ||
| encapsulation aal5ciscoppp virtual-template number | Specify PPP-over-ATM encapsulation. |
The peak rate value is typically identical to the average rate or some suitable multiple thereof (up to 64 times for the Cisco 7500 series routers).
The average rate value should be set to the line rate available at the remote site, because the remote line rate will typically have the lowest speed of the connection. For example, if the remote site has a T1 link, set the line rate to 1.536 Mbps. Because the average rate calculation on the ATM PVC includes the cell headers, a line rate value plus 10 or 15 percent may result in better remote line utilization.
The burst size depends on the number of cells that can be buffered by receiving ATM switches and is coordinated with the ATM network connection provider. If this value is not specified, the default, which is the equivalent to one maximum length frame on the interface, is used.
Operations, Administration and Maintenance (OAM) F5 cell loopback is provided by the remote AXIS shelf so OAM may be enabled. However, PPP over ATM is not typically an end-to-end ATM connection, and therefore enabling OAM is not recommended.
Once you configure the router for PPP over ATM, the PPP subsystem starts and the router attempts to send a PPP configure request to the remote peer. If the peer does not respond, the router periodically goes into a "listen" state and waits for a configuration request from the peer. After a timeout (typically 45 seconds), the router again attempts to reach the remote router by sending configuration requests.
The virtual access interface remains associated with a PVC as long as the PVC is configured. If you deconfigure the PVC, the virtual access interface is marked as deleted. If you shut down the associated ATM interface, you will also cause the virtual access interface to be marked as down (within 10 seconds), and you will bring the PPP connection down. If you set a keepalive timer of the virtual template on the interface, the virtual access interface uses the PPP echo mechanism to verify the existence of the remote peer. If an interface failure is detected and the PPP connection is brought down, the virtual access interface remains up.
E.164 is an International Telecommunications Union (ITU) specification for the ISDN international telephone numbering plan, which has traditionally only been used in telephone networks. The ATM Forum has defined three different 20-byte ATM End System Address (AESA) formats, along with the native E.164 format, for use in ATM networks. One of these 20-byte formats is the embedded E.164 AESA (E164_AESA) format.
With ATM E.164 auto conversion enabled, networks that operate based on ATM addressing formats can internetwork with networks based on E.164 addressing formats. The conversion requires components from addressing, routing, and signaling to perform properly.
For more information about E.164 and ATM address formats, see ATM Forum UNI 3.0, 3.1, and 4.0, and ITU E.164. Table 3 lists the ATM and E.164 address formats supported by ATM E.164 auto conversion.
| Address Type | Example |
|---|---|
Native E.164 | 1-800-555-1212 |
E164_AESA | 45.000018005551212F00000000.112233445566.00 |
E164_ZDSP | 45.000018005551212F00000000.000000000000.00 |
When ATM E.164 auto conversion is enabled, a Cisco router sets up ATM SVC connections based on E.164 addresses. The router uses ATM E164_AESA addresses to set up E.164 calls in a way similar to using ATM AESA addresses to set up ATM SVCs. The ATM AESA address on an interface and the ATM AESA address of a static map must be in E164_AESA format.
To configure ATM E.164 auto conversion, you must configure the ATM interface using E164_AESA or E164_ZDSP format. To enable E.164 auto conversion, use the following commands beginning in interface configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| interface atm slot/0 or interface atm slot/port-adapter/0 or interface atm number | Specify the ATM interface using the appropriate format of the interface atm command.1 | ||
| ip address ip-address mask | If IP routing is enabled on the system, optionally assign a source IP address and subnet mask to the interface. | ||
| pvc 0/5 qsaal | Configure the signaling PVC for the ATM main interface that uses SVCs. | ||
| exit | Return to interface configuration mode. | ||
| atm nsap-address nsap-address | Set the AESA address for the ATM interface using E164_AESA or E164_ZDSP address format. | ||
| Enable E.164 auto conversion on the interface. | |||
| exit | Return to interface configuration mode. | ||
| svc [name] nsap address | Specify the destination NSAP address using E164_AESA or E164_ZDSP address format. | ||
| protocol ip protocol-address | Specify the destination IP address of the SVC. |
Use the show interfaces atm command to verify that ATM E.164 auto conversion is running.
For an example of configuring ATM E.164 auto conversion, refer to the section "Configure ATM E.164 Auto Conversion Example" at the end of this chapter.
This section includes an overview of Circuit Emulation Services for ATM and a description of the configuration tasks.
Circuit emulation service internetworking function (CES-IWF) is a service based on ATM Forum standards that allows communications to occur between CBR and ATM UNI interfaces, that is, between non-ATM telephony devices (such as classic PBXs or TDMs) and ATM devices (such as Cisco 7200 series routers). Thus, a Cisco 7200 series router equipped with an ATM-CES port adapter offers a migration path from classic T1/E1 CBR data communications services to emulated CES T1/E1 unstructured (clear channel) services or structured (N x 64) services in an ATM network.
Figure 5 shows a simplified representation of CES-IWF functions in an ATM network.
With circuit emulation, data received from an external device at the edge of an ATM network is converted to ATM cells, sent through the network, reassembled into a bit stream, and passed out of the ATM network to its destination. T1/E1 circuit emulation does not interpret the contents of the data stream. All the bits flowing into the input edge port of the ATM network are reproduced at one corresponding output edge port.
An emulated circuit is carried across the ATM network on a PVC, which is configured through the network management system.
The ATM-CES port adapter offers two types of services:
The target application of the ATM-CES port adapter is access to a broadband public or private ATM network where multiservice consolidation of voice, video, and data traffic over a single ATM link is a requirement.
For an example of configuring CES, see the section "Configure Circuit Emulation Services Example" at the end of this chapter.
A circuit that you set up on a CBR port for unstructured service is always identified as "circuit 0," because only one such circuit can be established on any given CBR port. Such a circuit consumes the entire bandwidth of the port, which is provisioned manually at the time you set up the unstructured circuit and remains dedicated to that port, whether that port is actively transmitting CBR data or not.
A CES module converts CBR traffic into ATM cells for propagation through an ATM network. The ATM cell stream is directed to an outgoing ATM port or CBR port. If the outgoing port is an ATM port on the same Cisco 7200 series router, the PVC is called a "hard PVC." As a general rule when setting up a hard PVC, you must interconnect a CBR port and the ATM port in the same ATM-CES port adapter. Only hard PVCs are supported in the Cisco 7200 series router.
To configure the T1/E1 port on the ATM-CES port adapter for unstructured (clear channel) CES services, use the following commands beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| interface cbr slot/port | Specify the ATM-CES port adapter interface. | ||
| ces aal1 service [structured | unstructured] | Configure the port to perform unstructured CES services. The default is unstructured. | ||
| ces aal1 clock {adaptive | srts | synchronous} | Optionally, select the clock method. The default is synchronous. | ||
| ces dsx1 clock {loop-timed | network-derived} | If synchronous clocking is selected, configure the clock source. | ||
| Specify the circuit number for unstructured services and optionally specify the logical name of the PVC. If you do not specify a circuit name, the default is CBRx/x:x. | |||
| ces pvc 0 interface atm slot/port vci number vpi number | Define the particular ATM destination port for the PVC. | ||
| no shutdown | Change the shutdown state to up and enable the ATM interface, thereby beginning the segmentation and reassembly (SAR) operation on the interface. | ||
| no ces circuit 0 shutdown | Enable the PVC. |
Structured (N x 64 kbps) CES services differ from unstructured CES services in that the structured services allow you to allocate the bandwidth in a highly flexible and efficient manner. With the structured services, you use only the bandwidth actually required to support the active structured circuit(s) that you configure.
For example, in configuring an ATM-CES port adapter for structured service, you can define multiple hard PVCs for any given ATM-CES port adapter's T1/E1 port. The ATM-CES port adapter provides up to 24 time slots per T1 port and up to 31 time slots per E1 for defining structured CES circuits. To see the bandwidth that is required on an ATM link for this particular circuit, use the show ces circuit command.
For simplicity in demonstrating configuration tasks for structured CES services, the procedures in this section are directed primarily at setting up a single CES circuit per T1/E1 port. However, these procedures outline the essential steps and command syntax that you would use if you were to set up multiple CES circuits on a T1/E1 port.
Structured CES services require network clock synchronization by means of the synchronous clocking mode. You must select the clock source and define its priority locally for each Cisco 7200 series router in your network. You do this by means of the network-clock-select command.
To configure the T1/E1 port on the ATM-CES port adapter for structured (N x 64 kbps) CES services without CAS, use the following commands beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| interface cbr slot/port | Specify the ATM-CES port adapter interface. | ||
| ces aal1 service [structured | unstructured] | Configure the port to perform structured CES services. The default is unstructured. | ||
| ces aal1 clock {adaptive | srts | synchronous} | Optionally, select the clock method. The default is synchronous. Adaptive and SRTS are only available for unstructured mode. | ||
| ces dsx1 clock {loop-timed | network-derived} | If synchronous clocking is selected, configure the clock source. | ||
| ces dsx1 linecode {ami | b8zs} (for T1) ces dsx1 linecode {ami | hdb3} (for E1) | Specify the line code format used for the physical layer. The default is AMI. | ||
| ces dsx1 framing {esf | sf} (for T1) ces dsx1 framing {e1_crc_mfCASlt | e1_crc_mflt | e1_lt | e1_mfCAS_lt} (for E1) | Specify the framing format The default for T1 is ESF and for E1 is E1_LT. | ||
| Optionally, specify the line build out (cable length). Values are (in feet): 0_110, 110_220, 220_330, 330_440, 440_550, 550_660, 660_above, and square_pulse. The default is 0_110 feet. | |||
| Specify the circuit number for structured services and optionally specify the logical name of the PVC. For T1 structured service the range is 1 through 24. For E1 structured service the range is 1 through 31. If you do not specify a circuit name, the default is CBRx/x:x. | |||
| Specify the timeslots to be used by the PVC. For T1 the range is 1 through 24. For E1 structured service the range is 1 through 31. Use a dash to indicate a range (for example 1-24). Use a comma to separate the timeslot (for example, 1,3,5). | |||
| Optionally, configure the circuit cell delay variation. Range is 1 through 65535 milliseconds. The default range is 2000 milliseconds. | |||
| ces pvc circuit-number interface atm slot/port vci number vpi number | Define the particular ATM destination port for the PVC. | ||
| no shutdown | Change the shutdown state to up and enable the ATM interface, thereby beginning the segmentation and reassembly (SAR) operation on the interface. | ||
| no ces circuit circuit-number shutdown | Enable the PVC. |
Because the ATM-CES port adapter emulates constant bit rate services over ATM networks, it must be capable of providing support for handling channel-associated signaling (CAS) information introduced into structured CES circuits by PBXs and time-division multiplexing (TDM) devices. The ces circuit cas interface command provides this feature.
With respect to the CAS information carried in a CBR bit stream, an ATM-CES port adapter can be configured to operate as follows:
When the CAS feature is enabled for a CES circuit, the bandwidth of the DS0 channel is limited to 56 kbps for user data, because CAS functions consume 8 kbps of channel bandwidth for transporting the ABCD signaling bits. These signaling bits are passed transparently from the ingress node to the egress node as part of the ATM AAL1 cell stream.
In summary, when the optional CAS and on-hook detection features are enabled, the following conditions apply:
To configure the T1/E1 port on the ATM-CES port adapter for channel associated signaling, first use the commands in the "Configure Structured (N x 64) CES Services" section and then use the following commands beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| interface cbr slot/port | Specify the ATM-CES port adapter interface. | ||
| Enable channel associated signaling. | |||
| Optionally, enable the signal mode as robbed bit. | |||
| Optionally, enable on-hook detection. |
To direct a CBR port to use the network-derived clock, you must configure the CBR port with the ces dsx1 clock source network-derived interface command. For information on configuring the CBR port, refer to "Configure Unstructured (Clear Channel) CES Services" earlier in this chapter.
To establish the sources and priorities of the requisite clocking signals for an ATM-CES port adapter in a Cisco 7200 series router, use the following commands beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| network-clock-select 1 {atm | cbr} slot/port | Establish a priority 1 clock source. | ||
| network-clock-select 2 {atm | cbr} slot/port | Establish a priority 2 clock source. | ||
| network-clock-select 3 {atm | cbr} slot/port | Establish a priority 3 clock source. | ||
| network-clock-select 4 {atm | cbr} slot/port | Establish a priority 4 clock source. |
To verify the clock signal sources and priorities that you established in the previous procedure for your ATM-CES port adapter, use the show network-clocks privileged EXEC command.
For an example of configuring the network clock source and priority, see the section "Configure Network Clock Source Priority Example" at the end of this chapter.
The ATM-CES port adapter supports multiplexing of one or more PVCs over a virtual path (VP) that is shaped at a constant bandwidth. To use this feature, you configure a permanent virtual path (PVP) with a specific virtual path identifier (VPI). Any PVCs that are created subsequently with the same VPI are multiplexed onto this VP; the traffic parameters of individual PVCs are ignored.
The traffic shaping conforms to the peak rate that is specified when you create the VP. Any number of data PVCs can be multiplexed onto a VP.
To create a PVP, use the following commands beginning in interface configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| ||||
| pvc [name] vpi/vci | Optionally, create a PVC with a VPI that matches the VPI specified in Step 1. | ||
| exit | Exit interface configuration mode. | ||
| interface cbr slot/port ces pvc circuit-number interface atm slot/port vci number vpi number | Optionally, create a CES PVC with a VPI that matches the VPI specified in Step 1. |
The vpi value is the virtual path identifier to be associated with the PVP (valid values are in the range 0 to 255 inclusive). The peak-rate argument is the maximum rate (in kbps) at which the PVP is allowed to transmit data. Valid values are in the range 84 kbps to line rate. The default peak rate is the line rate.
When you create a PVP, two PVCs are created (with VCI 3 and 4) by default. These PVCs are created for VP end-to-end loopback and segment loopback OAM support.
The pvc command is rejected if a non-multiplexed PVC with the specified VPI value already exists. This could happen if you first create a PVC with a given VPI value and then you subsequently enter this command.
To display information about the PVP, use the show atm vp EXEC command.
For an example of virtual path shaping, see the section "Configure Virtual Path Shaping" at the end of this chapter.
This section describes how to configure routers that use a serial interface for ATM access through an ATM data service unit (ADSU). The configuration tasks include the steps necessary to enable Asynchronous Transfer Mode-Data Exchange Interface (ATM-DXI) encapsulation, select a multiprotocol encapsulation method using ATM-DXI, and set up a permanent virtual circuit (PVC) for the selected encapsulation.
In routers with a serial interface, an ADSU is required to provide the ATM interface to the network, convert outgoing packets into ATM cells, and reassemble incoming ATM cells into packets.
Any serial interface can be configured for multiprotocol encapsulation over ATM-DXI, as specified by RFC 1483. At the ADSU, the DXI header is stripped off, and the protocol data is segmented into cells for transport over the ATM network.
RFC 1483 describes two methods of transporting multiprotocol connectionless network interconnect traffic over an ATM network. One method allows multiplexing of multiple protocols over a single PVC. The other method uses different virtual circuits to carry different protocols. Our] implementation of RFC 1483 supports both methods and supports transport of Apollo Domain, AppleTalk, Banyan VINES, DECnet, IP, Novell IPX, ISO CLNS, and XNS traffic.
To configure ATM access over a serial interface, complete the tasks in the following sections. The first four tasks are required.
For an example of configuring ATM access over a serial interface, see the section "ATM Access over a Serial Interface Example" at the end of this chapter.
To begin configuring the serial interface for ATM access, enable the serial interface by using the following commands beginning in global configuration mode:
The supported protocols are Apollo Domain, AppleTalk, Banyan VINES, DECnet, IP, Novell IPX, ISO CLNS, and XNS.
For information about the addressing requirements of a protocol, see the relevant protocol configuration chapter in the Network Protocols Configuration Guide, Part 1, the Network Protocols Configuration Guide, Part 2, or the Network Protocols Configuration Guide, Part 3.
To enable ATM-DXI encapsulation on a serial or High-Speed Serial Interface (HSSI), use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Enable ATM-DXI encapsulation. |
An ATM-DXI PVC can be defined to carry one or more protocols as described by RFC 1483, or multiple protocols as described by RFC 1490.
To set up the ATM-DXI PVC and select an encapsulation method, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
dxi pvc vpi vci [snap | nlpid | mux] | Define the ATM-DXI PVC and the encapsulation method. |
The MUX (multiplex) option defines the PVC to carry one protocol only; each protocol must be carried over a different PVC. The SNAP (Subnetwork Access Protocol) option is LLC/SNAP multiprotocol encapsulation, compatible with RFC 1483; SNAP is the current default option. The network layer protocol identification (NLPID) option is multiprotocol encapsulation, compatible with RFC 1490; this option is provided for backward compatibility with the default setting in earlier versions in the Cisco IOS software.
This section describes how to map protocol addresses to the virtual channel identifier (VCI) and the virtual path identifier (VPI) of a PVC that can carry multiprotocol traffic. The protocol addresses belong to the host at the other end of the link. To map a protocol address to an ATM-DXI PVC, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
Map a protocol address to the ATM-DXI PVC's VPI and VCI. |
Repeat this task for each protocol to be carried on the PVC.
The supported protocols are Apollo Domain, AppleTalk, Banyan VINES, DECnet, IP, Novell IPX, ISO CLNS, and XNS.
For an example of configuring a serial interface for ATM, see the "ATM Access over a Serial Interface Example" section later in this chapter.
After configuring the serial interface for ATM, you can display the status of the interface, the ATM-DXI PVC, or the ATM-DXI map. To display interface, PVC, or map information, use the following commands in EXEC mode:
| Command | Purpose |
|---|---|
Display the serial ATM interface status. | |
Display the ATM-DXI PVC information. | |
Display the ATM-DXI map information. |
The atm oam flush command is a diagnostic tool that drops all OAM cells that are received on an ATM interface. To drop all incoming OAM cells on an ATM interface, use the following commands beginning in global configuration mode:
| Step | Command | Purpose | ||
|---|---|---|---|---|
| interface atm slot/0 or interface atm slot/port-adapter/0 or interface atm number | Specify the ATM interface using the appropriate format of the interface atm command.1 | ||
| atm oam flush | Specify that incoming OAM cells be dropped on the ATM interface. |
| 1Use the interface atm slot/0 command with the AIP on Cisco 7500 series routers, any ATM port adapter on the Cisco 7200 series routers, and the 1-port ATM-25 network module on the Cisco 2600 and 3600 series routers. Use the interface atm slot/port-adapter/0 command with any ATM port adapter on the Cisco 7500 series routers. Use the interface atm number command with the NPM on the Cisco 4500 and 4700 routers. Use interface atm 0 on the Cisco MC3810. |
After configuring the new interface, you can display its status. You can also display the current state of the ATM network and connected virtual circuits. To show current virtual circuits and traffic information, use the following commands in EXEC mode:
| Command | Purpose |
|---|---|
Display entries in the ARP table. | |
show atm class-links [vpi/vci | name] | Display PVC and SVC parameter configurations and where the parameter values are inherited from. |
|
show atm interface atm slot/port-adapter/0 show atm interface atm number | Display ATM-specific information about the ATM interface using the appropriate format of the show atm interface atm command.1 |
Display the list of all configured ATM static maps to remote hosts on an ATM network. | |
Display all active ATM PVCs and traffic information. | |
Display all active ATM SVCs and traffic information. | |
Display global traffic information to and from all ATM networks connected to the router, OAM statistics, and a list of counters of all ATM traffic on this router. | |
Display all active ATM virtual circuits (PVCs and SVCs) and traffic information. | |
|
show interfaces atm slot/port-adapter/0 show interfaces atm number | Display statistics for the ATM interface using the appropriate format of the show interfaces atm command.2 |
Display the clock signal sources and priorities that you established on the router. | |
Display SSCOP details for the ATM interface. |
| 1Use the show atm interface atm slot/0 command with the AIP on Cisco 7500 series routers, any ATM port adapter on the Cisco 7200 series routers, and the 1-port ATM-25 network module on the Cisco 2600 and 3600 series routers. Use the show atm interface atm slot/port-adapter/0 command with any ATM port adapter on the Cisco 7500 series routers. Use the show atm interface atm number command with the NPM on the Cisco 4500 and 4700 routers. Use show interface atm 0 on the Cisco MC3810. 2The description in the table footnote above applies for the show interfaces atm command. |
The examples in the following sections illustrate how to configure ATM for the features described in this chapter. The examples below are presented in the same order as the corresponding configuration task sections presented above:
The following example creates a PVC on an ATM main interface with AAL5/MUX encapsulation configured and a VBR-NRT QOS specified. For further information, refer to the sections "Create a PVC" and "Configure PVC Traffic Parameters" earlier in this chapter.
interface 2/0 pvc cisco 1/40 encapsulation aal5mux ip vbr-nrt 100000 50000 20 exit
The following example creates PVC 0/50 on ATM interface 3/0. It uses the global default LLC/SNAP encapsulation over AAL5. The interface is at IP address 1.1.1.1 with 1.1.1.5 at the other end of the connection. For further information, refer to the sections "Create a PVC" and "Map a Protocol Address to a PVC" earlier in this chapter.
interface atm 3/0 ip address 1.1.1.1 255.255.255.0 pvc 0/50 protocol ip 1.1.1.5 broadcast exit ! ip route-cache cbus
The following example is a typical ATM configuration for a PVC:
interface atm 4/0 ip address 172.21.168.112 255.255.255.0 atm maxvc 512 pvc 1/51 protocol ip 171.21.168.110 exit ! pvc 2/52 protocol decnet 10.1 broadcast exit ! pvc 3/53 protocol clns 47.004.001.0000.0c00.6e26.00 broadcast exit ! decnet cost 1 clns router iso-igrp comet exit ! router iso-igrp comet net 47.0004.0001.0000.0c00.6666.00 exit ! router igrp 109 network 172.21.0.0 exit ! ip domain-name CISCO.COM
Figure 6 illustrates a fully meshed network. The configurations for Routers A, B, and C follow the figure. In this example, the routers are configured to use PVCs. Fully meshed indicates that any workstation can communicate with any other workstation. Note that the two protocol statements configured in Router A identify the ATM addresses of Routers B and C. The two protocol statements in Router B identify the ATM addresses of Routers A and C. The two protocol statements in Router C identify the ATM addresses of Routers A and B. For further information, refer to the sections "Create a PVC" and "Map a Protocol Address to a PVC" earlier in this chapter.
ip routing ! interface atm 4/0 ip address 131.108.168.1 255.255.255.0 pvc 0/32 protocol ip 131.108.168.2 broadcast exit ! pvc 0/33 protocol ip 131.108.168.3 broadcast exit
ip routing ! interface atm 2/0 ip address 131.108.168.2 255.255.255.0 pvc test-b-1 0/32 protocol ip 131.108.168.1 broadcast exit ! pvc test-b-2 0/34 protocol ip 131.108.168.3 broadcast exit
ip routing ! interface atm 4/0 ip address 131.108.168.3 255.255.255.0 pvc 0/33 protocol ip 131.108.168.1 broadcast exit ! pvc 0/34 protocol ip 131.108.168.2 broadcast exit
The following example shows a typical ABR PVC configuration for the ATM-CES port adapter on a Cisco 7200 series router. In this example, the default peak cell rate and minimum cell rate is used (default PCR is the line rate and MCR is 0), and the ABR rate increase and decrease factor is set to 32. For further information, refer to the section "Configure PVC Traffic Parameters" earlier in this chapter.
interface atm 4/0 ip address 1.1.1.1 255.255.255.0 pvc 0/34 atm abr rate-factor 32 32 no shutdown exit
The following example enables PVC Discovery on the ATM main interface 2/0. The keyword subinterface is used so that all discovered PVCs with a VPI value of 1 will be assigned to the subinterface 2/0.1. For further information, refer to the section "Configure PVC Discovery" earlier in this chapter.
interface atm 2/0 pvc RouterA 0/16 ilmi exit atm ilmi-pvc-discovery subinterface exit ! interface atm 2/0.1 multipoint ip address 172.21.51.5 255.255.255.0
The following example enables Inverse ARP on an ATM interface and specifies an Inverse ARP time period of 10 minutes. For further information, refer to the section "Enable Inverse ARP" earlier in this chapter. For further information, refer to the section "Enable Inverse ARP" earlier in this chapter.
interface atm 2/0 pvc 1/32 inarp 10 exit
The following example enables OAM management on an ATM PVC. The PVC is assigned the name routerA and the VPI and VCI are 0 and 32, respectively. OAM management is enabled with a frequency of 3 seconds between OAM cell transmissions. For further information, refer to the section "Configure Generation of End-to-End F5 OAM Loopback Cells to Verify Connectivity" earlier in this chapter.
interface atm 2/0 pvc routerA 0/32 oam-pvc manage 3 oam retry 5 5 10
The following example configures the ILMI protocol on an ATM main interface. For further information, refer to the section "Configure Communication with the ILMI" earlier in this chapter.
interface 2/0 pvc cisco 0/16 ilmi exit
The following example is also a configuration for the fully meshed network shown in Figure 6, but this example uses SVCs. PVC 0/5 is the signaling PVC. For further information, refer to the following sections earlier in this chapter:
interface atm 4/0 ip address 131.108.168.1 255.255.255.0 atm nsap-address AB.CDEF.01.234567.890A.BCDE.F012.3456.7890.1234.12 atm maxvc 1024 pvc 0/5 qsaal exit ! svc svc-1 nsap BC.CDEF.01.234567.890A.BCDE.F012.3456.7890.1334.13 protocol ip 131.108.168.2 exit ! svc svc-2 nsap BC.CDEF.01.234567.890A.BCDE.F012.3456.7890.1334.12 protocol ip 131.108.168.3 exit
interface atm 2/0 ip address 131.108.168.2 255.255.255.0 atm nsap-address BC.CDEF.01.234567.890A.BCDE.F012.3456.7890.1334.13 atm maxvc 1024 pvc 0/5 qsaal exit ! svc svc-1 nsap AB.CDEF.01.234567.890A.BCDE.F012.3456.7890.1234.12 protocol ip 131.108.168.1 exit ! svc svc-2 nsap BC.CDEF.01.234567.890A.BCDE.F012.3456.7890.1334.12 protocol ip 131.108.168.3 exit
interface atm 4/0 ip address 131.108.168.3 255.255.255.0 atm nsap-address BC.CDEF.01.234567.890A.BCDE.F012.3456.7890.1334.12 atm maxvc 1024 pvc 0/5 qsaal exit ! svc nsap AB.CDEF.01.234567.890A.BCDE.F012.3456.7890.1234.12 protocol ip 131.108.168.1 exit ! svc nsap BC.CDEF.01.234567.890A.BCDE.F012.3456.7890.1334.13 protocol ip 131.108.168.2 exit
The following example on a Cisco 7500 series router assigns the ESI and selector field values and sets up the ILMI PVC. For further information, refer to the section "Configure the ESI and Selector Fields" earlier in this chapter.
interface atm 4/0 pvc 0/16 ilmi atm esi-address 345678901234.12
The following example assigns NSAP address AB.CDEF.01.234567.890A.BCDE.F012.3456.7890.1234.12 to ATM interface 4/0. For further information, refer to the section "Configure the Complete NSAP Address" earlier in this chapter.
interface atm 4/0 atm nsap-address AB.CDEF.01.234567.890A.BCDE.F012.3456.7890.1234.12
You can display the ATM address for the interface by executing the show interface atm command.
The following example configures an ATM interface for SVCs using multipoint signaling. For further information, refer to the section "Configure Point-to-Multipoint Signaling" earlier in this chapter.
interface atm 2/0 ip address 4.4.4.6 255.255.255.0 pvc 0/5 qsaal exit ! pvc 0/16 ilmi exit ! atm esi-address 3456.7890.1234.12 ! svc mcast-1 nsap cd.cdef.01.234566.890a.bcde.f012.3456.7890.1234.12 broadcast protocol ip 4.4.4.4 broadcast exit ! svc mcast-2 nsap 31.3233.34.352637.3839.3031.3233.3435.3637.3839.30 broadcast protocol ip 4.4.4.7 broadcast exit ! atm multipoint-signalling atm maxvc 1024
Figure 7 illustrates a source and destination router implementing traffic settings that correspond end-to-end. The output values for the source router correspond to the input values for the destination router. The following example specifies VBR-NRT traffic parameters on the source router. For further information, refer to the section "Configure SVC Traffic Parameters" earlier in this chapter.
interface atm 4/0 svc svc-1 nsap 47.0091.81.000000.0041.0B0A.1581.0040.0B0A.1585.00 vbr-nrt 1000 500 64 800 400 64 exit
The following example creates a VC class named main and configures UBR and encapsulation parameters. For further information, refer to the sections "Create a VC Class" and "Configure VC Parameters" earlier in this chapter.
vc-class atm main ubr 10000 encapsulation aal5mux ip
The following example creates a VC class named sub and configures UBR and PVC management parameters. For further information, refer to the sections "Create a VC Class" and "Configure VC Parameters" earlier in this chapter.
vc-class atm sub ubr 15000 oam-pvc manage 3
The following example creates a VC class named pvc and configures VBR-NRT and encapsulation parameters. For further information, refer to the sections "Create a VC Class" and "Configure VC Parameters" earlier in this chapter.
vc-class atm pvc vbr-nrt 10000 5000 64 encapsulation aal5snap
The following example applies the VC class named main to the ATM main interface 4/0. For further information, refer to the section "Apply a VC Class" earlier in this chapter.
interface atm 4/0 class main exit
The following example applies the VC class named sub to the ATM subinterface 4/0.5:
interface atm 4/0.5 multipoint class sub exit
The following example applies the VC class named pvc directly on the PVC 0/56:
interface atm 4/0.5 multipoint pvc 0/56 class pvc exit
The following example first configures an ILMI PVC on the main ATM interface 0/0. ILMI management is then configured on the ATM subinterface 0/0.1. For further information, refer to the section "Configure ILMI Management" earlier in this chapter.
interface atm 0/0 pvc routerA 0/16 ilmi exit ! interface atm 0/0.1 multipoint pvc 0/60 ilmi manage
The following example enables OAM management on an ATM PVC. The PVC is assigned the name routerA and the VPI and VCI are 0 and 32, respectively. OAM management is enabled with a frequency of 3 seconds between OAM cell transmissions. For further information, refer to the section "OAM Management for PVCs" earlier in this chapter.
interface atm 2/0 pvc routerA 0/32 oam-pvc manage 3 oam retry 5 5 10
The following example enables OAM management on an ATM SVC. The SVC is assigned the name routerZ and the destination NSAP address is specified. OAM management is enabled with a frequency of 3 seconds between OAM cell transmissions. For further information, refer to the section "OAM Management for SVCs" earlier in this chapter.
interface atm 1/0 svc routerZ nsap 47.0091.81.000000.0040.0B0A.2501.ABC1.3333.3333.05 oam-svc manage 3 oam retry 5 5 10
This section provides three examples of classical IP and ARP configuration, one each for a client and a server in an SVC environment, and one for ATM Inverse ARP in a PVC environment.
This example configures an ATM ARP client in an SVC environment. Note that the client in this example and the ATM ARP server in the next example are configured to be on the same IP network. For further information, refer to the section "Configure the Router as an ATM ARP Client" earlier in this chapter.
interface atm 2/0.5 atm nsap-address ac.2456.78.040000.0000.0000.0000.0000.0000.0000.00 ip address 10.0.0.2 255.0.0.0 pvc 0/5 qsaal atm arp-server nsap ac.1533.66.020000.0000.0000.0000.0000.0000.0000.00
The following example configures ATM on an interface and configures the interface to function as the ATM ARP server for the IP subnetwork. For further information, refer to the section "Configure the Router as an ATM ARP Server" earlier in this chapter.
interface atm 0/0 ip address 10.0.0.1 255.0.0.0 atm nsap-address ac.1533.66.020000.0000.0000.0000.0000.0000.0000.00 atm rate-queue 1 100 atm maxvc 1024 pvc 0/5 qsaal atm arp-server self
The following example configures ATM on an interface and then configures the ATM Inverse ARP mechanism on the PVCs on the interface, with Inverse ARP datagrams sent every 5 minutes on three of the PVCs. The fourth PVC will not send Inverse ATM ARP datagrams, but will receive and respond to Inverse ATM ARP requests. For further information, refer to the section "Configure Classical IP and Inverse ARP in a PVC Environment" earlier in this chapter.
interface atm 4/0 ip address 172.21.1.111 255.255.255.0 pvc 0/32 inarp 5 exit ! pvc 0/33 inarp 5 exit ! pvc 0/34 inarp 5 exit
No map-group and map-list commands are needed for IP.
The following examples assume that no permanent rate queues have been configured. The software dynamically creates rate queues when a pvc command creates a new PVC that does not match any user-configured rate queue. For further information, refer to the section "Use Dynamic Rate Queues" earlier in this chapter.
In the following example, the software sets the peak rate to the maximum that the PLIM will allow. Then it creates a rate queue for the peak rate of this VC.
interface 2/0 pvc 1/41 exit
In the following example, the software creates a 100-Mbps rate queue with an average rate of 50-Mbps and a burst size of 64 cells:
interface 2/0 pvc 2/42 vbr-nrt 100000 50000 64 exit
In the following example, the software creates a 15-Mbps rate queue and sets the average rate to the peak rate:
interface 2/0 pvc 3/43 ubr 15000 exit
The following example configures a rate queue tolerance on the ATM interface with slot 2 and port 0. A tolerance-value of 20 is specified, which will apply to SVCs, discovered VCs, and PVCs.
interface atm 2/0 atm rate-queue tolerance svc pvc 20
The following example provides a minimal configuration of an ATM interface to support AAL3/4 and SMDS encapsulation; no protocol configuration is shown. For further information, refer to the section "Configure ATM Subinterfaces for SMDS Networks" earlier in this chapter.
interface atm 3/0 atm aal aal3/4 atm smds-address c140.888.9999 atm vp-filter 0 atm multicast e180.0999.9999 atm pvc 30 0 30 aal34smds
The following example shows how IP dynamic routing might coexist with static routing of another protocol:
interface atm 3/0 ip address 172.21.168.112 255.255.255.0 atm aal aal3/4 atm smds-address c140.888.9999 atm multicast e180.0999.9999 atm vp-filter 0 atm pvc 30 0 30 aal34smds map-group atm appletalk address 10.1 appletalk zone atm ! map-group atm atalk 10.2 smds c140.8111.1111 broadcast
This example shows that IP configured is dynamically routed, but that AppleTalk is statically routed. An AppleTalk remote host is configured at address 10.2 and is associated with SMDS address c140.8111.1111.
AAL3/4 associates a protocol address with an SMDS address, as shown in the last line of this example. In contrast, AAL5 static maps associate a protocol address with a PVC number.
In the following example, three AAL5-SNAP PVCs are created on the same ATM interface. The router will broadcast all spanning tree updates to these AAL5-SNAP PVCs. No other virtual circuits will receive spanning tree updates. For further information, refer to the section "Configure Fast-Switched Transparent Bridging for SNAP PVCs" earlier in this chapter.
interface atm 4/0 ip address 1.1.1.1 255.0.0.0 pvc 1/33 pvc 1/34 pvc 1/35 bridge-group 1 ! bridge 1 protocol dec
The following example configures PPP over ATM to use PPP unnumbered link and Challenge Handshake Authentication Protocol (CHAP) authentication. For further information, refer to the section "Configure PPP over ATM" earlier in this chapter.
configure terminal ! interface virtual-template 2 encapsulation ppp ip unnumbered ethernet 0/0 ppp authentication chap ! interface atm 2/0.2 point-to-point pvc 0/34 encapsulation aal5ciscoppp virtual-template 2 exit
The following example configures ATM E.164 auto conversion on an ATM interface. Figure 8 illustrates this example. For further information, refer to the section "Configure ATM E.164 Auto Conversion" earlier in this chapter.
interface atm 0 multipoint ip address 120.45.20.81 255.255.255.0 pvc 0/5 qsaal exit ! atm nsap-address 45.000120045020081F00000000.112233445566.00 atm e164 auto-conversion svc nsap 45.000120045020071F00000000.665544332211.00 protocol ip 120.45.20.71 exit
Upon entering an E.164 network at Router A, the destination E.164 address, extracted from the E164_AESA of the static map, is signaled in the Called Party Address. The destination E164_AESA address from the E164_AESA of the static map is signaled in the Called Party Subaddress.
The source E.164 address, extracted from the E164_AESA of the interface, is signaled in the Calling Party Address. The source E164_AESA address from the E164_AESA of the interface is signaled in the Calling Party Subaddress.
Upon leaving the E.164 network, the original Called and Calling Party addresses are extracted from the subaddresses and moved into the Called and Calling Parties. The call is then forwarded.
E164_ZDSP addresses are simply converted to E.164 addresses upon entering the E.164 network, and converted back to E164_ZDSP addresses upon leaving the network.
The following example shows how to configure the T1 port on the ATM-CES port adapter for unstructured (clear channel) CES services. In this example, the T1 port uses adaptive clocking and the circuit name "CBR-PVC-A." For further information, refer to the section "Configure Circuit Emulation Services (CES)" earlier in this chapter.
interface cbr 6/0 ces aal1 service unstructured ces aal1 clock adaptive atm clock internal ces dsx1 clock network-derived ces circuit 0 circuit-name CBR-PVC-A ces pvc 0 interface atm 6/0 vpi 0 vci 512 no shutdown no ces circuit 0 shutdown exit
The following example shows how to establish the T1 port on the ATM-CES port adapter as the first clocking priority and the ATM port as the second clocking priority. For further information, refer to the section "Configure Network Clock Source Priority Example" earlier in this chapter.
network-clock-select 1 cbr 6/0 network-clock-select 2 atm 6/0 exit
The following example shows a typical configuration for the ATM-CES port adapter with VP shaping on a Cisco 7200 series router. In this example, a VP is created with the VPI value of 1 and with a peak rate of 2000 kbps. The subsequent VCs created, one data VC and one CES VC, are multiplexed onto this VP. For further information, refer to the section "Configure Virtual Path Shaping Exampleearlier in this chapter.
interface atm 6/0 ip address 2.2.2.2 255.255.255.0 atm pvp 1 2000 pvc 1/33 no shutdown exit interface cbr 6/1 ces circuit 0 ces pvc 0 interface atm6/0 vpi 1 vci 100 exit
The example in this section illustrates how to configure a serial interface for ATM access.
In the following example, serial interface 0 is configured for ATM-DXI with MUX encapsulation. Because MUX encapsulation is used, only one protocol is carried on the PVC. This protocol is explicitly identified by a dxi map command, which also identifies the protocol address of the remote node. This PVC can carry IP broadcast traffic.
interface serial 0 ip address 172.21.178.48 encapsulation atm-dxi dxi pvc 10 10 mux dxi map ip 172.21.178.4 10 10 broadcast
The following example shows the configuration needed to connect two ATM port adapters back to back. Two routers, each containing an ATM port adapter, is connected directly with a standard cable, that allows you to verify the operation of the ATM port or to directly link the routers to build a larger node.
By default, the ATM port adapter expects a connected ATM switch to provide transmit clocking. To specify that the ATM port adapter generates the transmit clock internally for SONET PLIM operation, add the atm clock internal command to your configuration.
interface atm 3/0 ip address 192.168.1.10 255.0.0.0 no keepalive atm clock internal pvc 1/35 ! protocol ip 192.168.1.20 broadcast
interface atm 3/0 ip address 192.168.1.20 255.0.0.0 no keepalive atm clock internal pvc 1/35 ! protocol ip 192.168.1.10 broadcast
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