|
|
This chapter describes features that either depend on special signaling services offered by an ISDN network service provider or overcome an inability to deliver certain signals.
For a complete description of the ISDN signaling commands in this chapter, refer to the "ISDN Special Signaling Commands" chapter of the Dial Solutions Command Reference. To locate documentation of other commands that appear in this chapter, use the command reference master index or search online.
This following sections of this chapter describe how to configure special signaling features of ISDN:
For examples of these signaling features, see the "ISDN Signaling Configuration Examples" section. For help in troubleshooting ISDN signaling features, see the "Troubleshoot ISDN" section.
The ISDN AOC feature also supports, for the AOC-D service, an optional configurable short-hold mode which provides a dynamic idle timeout by measuring the call charging period, based on the frequency of the AOC-D or the AOC-E message from the network. The short-hold mode allows users to track call costs and to control and possibly reduce tariff charges. The short-hold mode idle time will do the following:
Incoming calls are disconnected using the static dialer idle timeout value.
The AOC-D and AOC-E messages are part of the Facility Information Element (IE) message. Its contents can be verified with the debug q931 command. Call accounting information from AOC-D and AOC-E messages is stored in SNMP MIB objects.
ISDN AOC is provided for ISDN PRI NET5 and ISDN BRI NET3 switch types only. AOC information at call setup is not supported.
AOC-D message---ISDN Advice of Charge information sent during a call. The message is sent periodically by the network to subscribers of AOC during-call services.
Short-hold mode---Configurable option for outgoing calls that causes the dialer idle timeout to be at the end of the current charging period, after a specified minimum idle time has elapsed. If the link has been idle less than the specified minimum time, the call stays connected into another charging period.
No configuration is required to enable ISDN AOC.
However, you can configure the optional short-hold minimum idle timeout period for outgoing calls; the default minimum idle timeout is 120 seconds. If the short-hold option is not configured, the router default is to use the static dialer idle timeout. If the short-hold idle timeout has been configured but no charging information is available from the network, the static dialer idle timeout applies.
To configure an ISDN interface and provide the AOC short-hold mode option on an ISDN interface, use the following commands:
Step 2 Configure Dialer Profiles or legacy DDR for outgoing calls, as described in the "Dial-on-Demand Routing" part of this manual, making sure to do the following:
Step 3 Configure each specified dialer map class, providing a dialer idle timeout, or ISDN short-hold timeout, or both for outgoing calls, as described in this chapter.
| Step | Command | Purpose | ||
|---|---|---|---|---|
| map-class dialer classname | Specify the dialer map class. | ||
| dialer idle-timeout seconds | (Optional) Specify a static idle timeout for the map class to override the static line-idle timeout configured on the BRI interface. | ||
| dialer isdn short-hold seconds | Specify a dialer ISDN short-hold timeout for the map class. |
Use the following command to monitor ISDN AOC call information:
| Command | Purpose |
|---|---|
show isdn {active | history | memory | service | status | timers} |
Use of a single D channel to control multiple PRI interfaces can free one B channel on each interface to carry other traffic.
Any hard failure causes a switchover to the backup D channel and currently connected calls remain connected.
Once the channelized T1controllers are configured for ISDN PRI, only the NFAS primary D channel must be configured; its configuration is distributed to all the members of the associated NFAS group.
NFAS is only supported with a channelized T1 controller and, as a result, be ISDN PRI capable.
The router must connect to either a 4ess, dms250, dms100, or a National ISDN switch type. Table 16 shows the applicable ISDN switch types and supported NFAS types:
In addition, the router's channelized T1 controllers must be configured for ISDN, as described in the "Configuring ISDN PRI" section of the "Configuring Channelized E1 and Channelized T1" chapter of this manual.
| Switch Type | NFAS Type |
|---|---|
Lucent 4ESS | Custom NFAS |
Nortel DMS250 | Custom NFAS |
Nortel DMS100 | Custom NFAS |
Lucent 5ESS | Custom - Does not support NFAS |
Lucent 5ESS | NI-2 NFAS |
AGCS GTD5 | NI-2 NFAS |
Other Switch Types | NI-2 NFAS |
The following terms are used in this description of ISDN NFAS:
24 B channel interface---A PRI channel group configured to have no NFAS D channel; all its channels are B channels.
NFAS group---A PRI channel group (the group of interfaces) under control of a single D channel. The channel group can include all the ISDN channels on multiple T1 controllers. Cisco IOS supports ten PRI interfaces in an NFAS group with a primary D channel and a backup D channel. Five NFAS groups are supported in a single chassis.
NFAS member---A PRI interface in an NFAS group. For example, an NFAS group might include serial interfaces 1/0:23, 1/1:23, and 2/0:23 if T1 controllers 1/0, 1/1, and 2/0 are configured for NFAS.
non-facility associated signaling (NFAS)---An ISDN service that allows a single D channel to control multiple PRI interfaces. Use of a single D channel to control multiple PRI interfaces can free one B channel on each interface to carry other traffic.
You can also disable a channel or interface, if necessary, and monitor NFAS groups and ISDN service. To do so, use the commands in the following sections:
See the "NFAS Primary and Backup D Channels Example" in this chapter for a complete ISDN, NFAS, and DDR configuration.
This section documents tasks used to configure NFAS with D channel backup. When configuring NFAS, you use an extended version of the ISDN pri-group command to specify the following values for the associated channelized T1 controllers configured for ISDN:
To configure ISDN NFAS, use the following commands in controller configuration mode:
| Command | Purpose |
|---|---|
pri-group timeslots 1-24 nfas_d primary nfas_interface number nfas_group number | On one channelized T1 controller, configure the NFAS primary D channel. |
pri-group timeslots 1-24 nfas_d backup nfas_interface number nfas_group number | On a different channelized T1 controller, configure the NFAS backup D channel to be used if the primary D channel fails. |
pri-group timeslots 1-24 nfas_d none nfas_interface number nfas_group number | On other channelized T1 controllers, configure a 24 B channel interface, if desired. (Optional) |
For an example of configuring three T1 controllers for the NFAS primary D channel, the backup D channel, and 24 B channels, along with the DDR configuration for the PRI interface, see the "NFAS Primary and Backup D Channels Example" section.
When a backup NFAS D channel is configured and the primary NFAS D channel fails, rollover to the backup D channel is automatic and all connected calls stay connected.
If the primary NFAS D channel recovers, the backup NFAS D channel remains active and does not switch over again unless the backup NFAS D channel fails.
You can disable a specified channel or an entire PRI interface, thus taking it out of service or put it into one of the other states that is passed in to the switch. To disable a specific channel or PRI interface, use one of the following commands in interface configuration mode:
| Command | Purpose |
isdn service dsl number b_channel number state state-value | Take an individual B channel out of service or set it to a different state. |
isdn service dsl number b_channel 0 state state-value | Set the entire PRI interface to the specified state. |
These are the supported state values:
To monitor NFAS groups, use the following command in EXEC mode:
| Command | Purpose |
|---|---|
show isdn nfas group number | Display information about members of an NFAS group. |
To display information about ISDN channel service states, use the following command in EXEC mode:
| Command | Purpose |
|---|---|
Display information about ISDN channels and the service states. |
Configuring BRIs for semipermanent connection requires only that you use a keyword that indicates semipermanent connections when you are setting up network addressing as described in the previous section of this chapter.
To configure a BRI for semipermanent connections, use the following commands:
Step 1 Set up the ISDN lines and ports as described in the "Setting Up ISDN Basic Rate Service" chapter or in the "Configure ISDN PRI" section of the "Configuring Channelized E1 and Channelized T1" chapter.
Step 2 Configure dial-on-demand routing on a selected interface, as described in the "Dial-on-Demand Routing" part of this manual.
When you get to the DDR network addressing step, use the following commands in interface configuration mode:
| Command | Purpose |
|---|---|
dialer map protocol next-hop-address name hostname spc [speed 56 | 64] [broadcast] dial-string[:isdn-subaddress] | Define the remote recipient's protocol address, host name, and dialing string; indicate semipermanent connections; optionally, provide the ISDN subaddress; set the dialer speed to 56 or 64 kbps, as needed. |
To configure the BRI to use the ISDN connection as a leased-line service, use the following commands in global configuration mode:
| Command | Purpose |
|---|---|
isdn switch-type switch-type | Configure the BRI switch type, as specified by the local service provider. |
isdn leased-line bri number 128 | Specify the BRI interface number. |
To disable leased-line service if you no longer want to support it on a specified ISDN BRI, use the following command in global configuration mode:
| Command | Purpose |
|---|---|
no isdn leased-line bri number | Remove leased line configuration from a specified ISDN BRI interface. |
This feature requires one or more ISDN BRI hardware interfaces that support channel aggregation and service provider support for ISDN channel aggregation at 128 kbps. At the time of Release 11.2, service providers offered support for ISDN channel aggregation at 128 kbps only in Japan.
| Command | Purpose |
|---|---|
Select the service provider switch type. | |
Configure a specified BRI for access over leased lines. |
To complete the configuration of the interface, see the "Configure a Synchronous Serial Ports" in this manual.
To remove the leased-line service configuration from a specified ISDN BRI, use the following command in global configuration mode:
| Command | Purpose |
|---|---|
no isdn leased-line bri number | Remove leased line configuration from a specified ISDN BRI interface. |
You can enable a serial or ISDN interface to accept calls and dynamically change the encapsulation in effect on the interface when the remote device does not signal the call type. For example, if an ISDN call does not identify the call type in the lower-layer compatibility fields and is using an encapsulation that is different from the one configured on the interface, the interface can change its encapsulation type dynamically.
This feature enables interoperation with ISDN terminal adapters that use V.120 encapsulation but do not signal V.120 in the call setup message. An ISDN interface that by default answers a call as synchronous serial with PPP encapsulation can change its encapsulation and answer such calls.
Automatic detection is attempted for the first 10 seconds after the link is established or the first five packets exchanged over the link, whichever is first.
To enable automatic detection of encapsulation type, use the following command in interface configuration mode:
| Command | Purpose |
|---|---|
autodetect encapsulation encapsulation-type | Enable automatic detection of encapsulation type on the specified interface. |
You can specify one or more encapsulations to detect. Cisco IOS software currently supports automatic detection of PPP and V.120 encapsulations.
Historically, Combinet devices supported only the Combinet Packet Protocol (CPP) for negotiating connections over ISDN B channels. To enable Cisco routers to communicate with those Combinet bridges, the Cisco IOS supports a new CPP encapsulation type.
To enable routers to communicate over ISDN interfaces with Combinet bridges that support only CPP, use the following commands in interface configuration mode:
| Step | Command | Purpose |
|---|---|---|
Step 1 | Specify CPP encapsulation. | |
Step 2 | Enable CPP callback acceptance. | |
Step 3 | Enable CPP authentication. |
Now most Combinet devices support PPP. Cisco routers can communicate over ISDN with these devices by using PPP encapsulation, which supports both routing and fast switching.
Cisco routers can also half-bridge IP and IPX with Combinet devices that support only CPP. To configure this feature, you only need to set up the addressing with the ISDN interface as part of the remote subnet; no additional commands are required.
You can troubleshoot ISDN by using the following commands:
This section provides the following configuration examples:
This section provides the following ISDN Advice of Charge configuration examples:
This example shows ISDN PRI configured on an E1 controller. Legacy DDR is configured on the ISDN D channel (serial interface 0:15) and propagates to all ISDN B channels. A static dialer idle-timeout is configured for all incoming calls on the B channels, but the map classes are configured independently of it. Map classes Kappa and Beta use AOC charging unit duration to calculate the timeout for the call. A short-hold idle timer is set so that if the line is idle for 10 or more seconds, the call is disconnected when the current charging period ends. Map class Iota uses a static idle timeout.
version 11.2 service timestamps debug datetime msec service timestamps log datetime msec ! hostname A ! username c2503isdn password 7 1511021F0725 username B password 7 110A1016141D29 username C password 7 1511021F072508 isdn switch-type primary-net5 ! controller E1 0 pri-group timeslots 1-31 ! interface Serial 0:15 ip address 10.0.0.35 255.0.0.0 encapsulation ppp dialer idle-timeout 150 dialer map ip 10.0.0.33 name c2503isdn class Iota 06966600050 dialer map ip 10.0.0.40 name B class Beta 778578 dialer map ip 10.0.0.45 name C class Kappa 778579 dialer-group 1 ppp authentication chap ! map-class dialer Kappa dialer idle-timeout 300 dialer isdn short-hold 120 ! map-class dialer Iota dialer idle-timeout 300 ! map-class dialer Beta dialer idle-timeout 300 dialer isdn short-hold 90 ! dialer-list 1 protocol ip permit
This example shows ISDN BRI configured as a member of two dialer pools for Dialer Profiles.
version 11.2 service timestamps debug datetime msec service timestamps log datetime msec ! hostname delorean ! username spanky password 7 0705344245 username delorean password 7 1511021F0725 isdn switch-type basic-net3 ! interface BRI0 description Connected to NTT 81012345678901 no ip address dialer pool-member 1 max-link 1 dialer pool-member 2 max-link encapsulation ppp no fair-queue ! interface Dialer1 ip address 7.1.1.8 255.255.255.0 encapsulation ppp dialer remote-name spanky dialer string 81012345678902 class Omega dialer pool 1 dialer-group 1 ppp authentication chap ! interface Dialer2 ip address 8.1.1.8 255.255.255.0 encapsulation ppp dialer remote-name dmsisdn dialer string 81012345678902 class Omega dialer string 14153909503 class Gamma dialer pool 2 dialer-group 1 ppp authentication chap ! map-class dialer Omega dialer idle-timeout 60 dialer isdn short-hold 150 ! map-class dialer Gamma dialer isdn short-hold 60 ! dialer-list 1 protocol ip permit
This section provides the following configuration examples:
The following example configures ISDN PRI and NFAS on three T1 controllers of a Cisco 7500 series router. The NFAS primary D channel is configured on the 1/0 controller, and the NFAS backup D channel is configured on the 1/1 controller. No NFAS D channel is configured on the 2/0 controller; it is configured for 24 B channels.
Once the NFAS primary D channel is configured, it is the only interface you see and have to configure; DDR configuration for the primary D channel---which is distributed to all B channels---is also included in this example.
isdn switch-type primary-4ess ! ! NFAS primary D channel on the channelized T1 controller in 1/0 controller t1 1/0 framing esf linecode b8zs pri-group timeslots 1-24 nfas_d primary nfas_interface 0 nfas_group 1 ! ! NFAS backup D channel on the channelized T1 controller in 1/1 controller t1 1/1 framing esf linecode b8zs pri-group timeslots 1-24 nfas_d backup nfas_interface 1 nfas_group 1 ! ! NFAS 24 B channels on the channelized T1 controller in 2/0 controller t1 2/0 framing esf linecode b8zs pri-group timeslots 1-24 nfas_d none nfas_interface 2 nfas_group 1 ! ! NFAS primary D channel interface configuration for PPP and DDR. This ! configuration is distributed to all the B channels in NFAS group 1 on the ! three channelized T1 controllers. ! interface Serial 1/0:23 ip address 1.1.1.2 255.255.255.0 no ip mroute-cache encapsulation ppp dialer map ip 1.1.1.1 name flyboy 567898 dialer map ip 1.1.1.3 name flyboy 101112345678 dialer map ip 1.1.1.4 name flyboy 01112345678 dialer-group 1 no fair-queue no cdp enable ppp authentication chap
The following example puts the entire PRI interface back in service after it previously had been taken out of service:
isdn service dsl 0 b-channel 0 state 0
The following example configures the BRI 0 interface for leased-line access at 128 kbps. Because of the leased-line---not dialed---environment, configuration of ISDN called and calling numbers are not needed and not used. The BRI 0 interface is henceforth treated as a synchronous serial interface, with the default HDLC encapsulation.
isdn leased-line bri 0 128
The following example configures the BRI 0 interface for PPP encapsulation:
interface bri 0 ip address 1.1.1.2 255.255.255.0 encapsulation ppp bandwidth 128
Posted: Mon May 3 12:27:40 PDT 1999
Copyright 1989-1999©Cisco Systems Inc.