|
|
This chapter does not address routing issues, dialer configuration, and dial backup. For information about those topics, see the "Dial-on-Demand Routing" part of this manual.
For hardware technical descriptions, and for information about installing the router interfaces, refer to the hardware installation and maintenance publication for your particular product.
For a complete description of the BRI commands in this chapter, refer to the "ISDN Basic Rate Service Setup 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.
Perform the tasks in the following sections to configure ISDN lines and interfaces:
You can also perform the following ISDN troubleshooting and maintenance tasks:
You can also optionally configure snapshot routing for ISDN interfaces. Snapshot routing is a method of learning remote routes dynamically and keeping the routes available for a specified period of time, even though routing updates are not exchanged during that period. See the "Configuring Snapshot Routing" chapter in the "Cost-Control Solutions" part of this manual for detailed information about snapshot routing.
To place calls on an ISDN interface, you must configure it with dial-on-demand routing (DDR). For configuration information about ISDN using DDR, see the "Dial-on-Demand Routing" part of this manual. For command information, refer to the "Dial-on-Demand Routing" part of the Dial Solutions Command Reference.
To configure bandwidth on demand, see the "Configuring Legacy DDR Spokes" chapter or the "Configuring Legacy DDR Hubs" chapter of this manual.
See the end of this chapter for the "ISDN BRI Configuration Examples" section.
This process varies dramatically from provider to provider on a national and international basis. However, some general guidelines follow:
When you order ISDN service, request the BRI switch configuration attributes specified in Table 11.
| Switch Type | Configuration |
|---|---|
| DMS-100 BRI | 2 B channels for voice and data. 2 directory numbers assigned by service provider. 2 SPIDs required; assigned by service provider. Functional signaling. Dynamic terminal endpoint identifier (TEI) assignment. Maximum number of keys = 64. Release key = no, or key number = no. Ringing indicator = no. EKTS = no. PVC = 2. Request delivery of calling line ID on Centrex lines. Set speed for ISDN calls to 56 kbps outside local exchange. Directory number 1 can hunt to directory number 2. |
| 5ESS Custom BRI | For Data Only
2 B channels for data. For Voice and Data (Use these values only if you have an ISDN telephone connected.) |
| 5ESS National ISDN (NI-1) BRI | Terminal type = A. 2 B channels for voice and data. 2 directory numbers assigned by service provider. 2 SPIDs required; assigned by service provider. Set speed for ISDN calls to 56 kbps outside local exchange. Directory number 1 can hunt to directory number 2. |
To check the MTU size and the buffers and, if necessary, to configure the buffers and the MTU size, complete the following tasks beginning in EXEC mode:
| Task | Command |
|---|---|
| Check the MTU size. | show interfaces bri number |
| Check the free buffers. | show buffers |
| Configure the buffers. | configure terminal
buffers big permanent number |
To configure the ISDN global characteristics, complete the tasks in the following sections:
To configure the switch type, complete the following task in global configuration mode:
| Task | Command |
|---|---|
| Select the service provider switch type.1 | isdn switch-type switch-type |
Table 12 lists the ISDN BRI switch types by geographic areas.
| Keywords by Area | Switch Type |
|---|---|
| none | No switch defined |
| Australia | |
| basic-ts013 | Australian TS013 switches |
| Europe | |
| basic-1tr6 | German 1TR6 ISDN switches |
| basic-nwnet3 | Norway NET3 switches (phase 1) |
| basic-net3 | NET3 ISDN switches; covers the Euro-ISDN E-DSS1 signaling system and is ETSI-compliant. |
| vn2 | French VN2 ISDN BRI switches |
| vn3 | French VN3 ISDN BRI switches |
| vn4 | French VN4 ISDN BRI switches |
| Japan | |
| ntt | Japanese NTT ISDN switches |
| North America | |
| basic-5ess | AT&T basic rate switches |
| basic-dms100 | NT DMS-100 basic rate switches |
| basic-ni1 | National ISDN-1 switches |
| New Zealand | |
| basic-nznet3 | New Zealand Net3 switches |
By default TEI negotiation occurs when the router is powered on. To define when TEI negotiation will occur, perform the following task in global configuration mode:
| Task | Command |
|---|---|
| Determine when ISDN TEI negotiation occurs. | isdn tei [first-call | powerup] |
In addition, you can configure the following optional interface characteristics on the BRI:
To specify an ISDN Basic Rate Interface (BRI) and enter interface configuration mode, perform the following task in global configuration mode:
| Task | Command |
|---|---|
| Specify the interface and enter interface configuration mode. | interface bri number interface bri slot/port (Cisco 7200 series) |
| Specify an IP protocol address for the interface. | ip address ip-address mask |
PPP encapsulation is configured for most ISDN communication.
| Task | Command |
|---|---|
| Configure PPP Encapsulation | encapsulation ppp |
The router might need to communicate with devices that require a different encapsulation protocol or the router might send traffic over a Frame Relay or X.25 network. For more information, see the "Configuring Frame Relay on ISDN D and B Channels" and "Configuring X.25 on ISDN D and B Channels" chapters of this manual.
To configure the router for automatic detection of encapsulation type on incoming calls, or to configure encapsulation for Combinet compatibility, see the "Configuring Special ISDN Signaling" chapter of this manual.
The steps in this section support the primary goals of network addressing:
Intermediate steps that use shared argument values tie the host identification and dial string to the interesting packets to be transmitted to that host.
To configure network addressing, complete the following tasks beginning in interface configuration mode:
| Task | Command |
|---|---|
| Step 1 (Most locations) Define the remote recipient's protocol address, host name, and dialing string; optionally, provide the ISDN subaddress; set the dialer speed to 56 or 64 kbps, as needed. or (Germany) Use the command keyword that enables ISDN semipermanent connections. | dialer map protocol next-hop-address name hostname speed 56|64 dial-string[:isdn-subaddress] dialer map protocol next-hop-address name hostname spc [speed 56 | 64] [broadcast] dial-string[:isdn-subaddress] |
| Step 2 Assign the interface to a dialer group to control access to the interface. | dialer-group group-number |
| Step 3 Associate the dialer group number with an access list number. | dialer-list dialer-group list access-list-number |
| Step 4 Define an access list permitting or denying access to specified protocols, sources, or destinations. Permitted packets cause the router to place a call to the destination protocol address. | access-list access-list-number {deny | permit} protocol source address source-mask destination destination-mask |
For more information about defining outgoing call numbers, see the "Configuring DDR" chapter.
Currently, only the DMS-100 and NI-1 switch types require SPIDs. The AT&T 5ESS switch type may support a SPID, but we recommend that you set up that ISDN service without SPIDs. In addition, SPIDs have significance at the local access ISDN interface only. Remote routers are never sent the SPID.
A SPID is usually a seven-digit telephone number with some optional numbers. However, service providers may use different numbering schemes. For the DMS-100 switch type, two SPIDs are assigned, one for each B channel.
To define the SPIDs and the local directory number (LDN) on the router, perform the following tasks in interface configuration mode:
| Task | Command |
|---|---|
| Specify a SPID and local directory number for the B1 channel. | isdn spid1 spid-number [ldn] |
| Specify a SPID and local directory number for the B2 channel. | isdn spid2 spid-number [ldn] |
The LDN is optional but might be necessary if the router is to answer calls made to the second directory number.
This task applies only to Cisco 2500 series, Cisco 3000 series, and Cisco 4000 series routers that have a BRI.
Calling line identification (CLI, also called caller ID) screening adds a level of security by allowing you to screen incoming calls. You can verify that the calling line ID is from an expected origin. CLI screening requires a local switch that is capable of delivering the CLI to the router.
To configure caller ID screening, perform the following task in interface configuration mode:
| Task | Command |
|---|---|
| Configure caller ID screening. | isdn caller number |
When multiple devices are attached to an ISDN BRI, you can ensure that only a single device answers an incoming call by verifying the number or subaddress in the incoming call against the device's configured number or subaddress or both.
You can specify that the router verify a called-party number or subaddress number in the incoming setup message for ISDN BRI calls, if the number is delivered by the switch. You can do so by configuring the number that is allowed. To configure verification, perform the following task in interface configuration mode:
| Task | Command |
|---|---|
| Specify that the router verify a called-party number or subaddress number in the incoming setup message. | isdn answer1 [called-party-number][:subaddress] |
Verifying the called-party number ensures that only the desired router responds to an incoming call. If you want to allow an additional number for the router, you can configure it, too.
To configure a second number to be allowed, perform the following task in interface configuration mode:
| Task | Command |
|---|---|
| Specify that the router verify a second called-party number or subaddress number in the incoming setup message. | isdn answer2 [called-party-number][:subaddress] |
A router with an ISDN BRI interface might need to supply the ISDN network with a billing number for outgoing calls. Some networks offer better pricing on calls in which the number is presented. When configured, this information is included in the outgoing call Setup message.
To configure the interface to identify the billing number, perform the following task in interface configuration mode:
| Task | Command |
|---|---|
| Specify the calling party number. | isdn calling-number calling-number |
This command can be used with all switch types except German 1TR6 ISDN BRI switches.
When calls are made at 56 kbps but delivered by the ISDN network at 64 kbps, the incoming data can be corrupted.
However, on ISDN calls, if the receiving side is informed that the call is not an ISDN call from end to end, it can set the line speed for the incoming call.
To set the speed for incoming calls recognized as not ISDN end-to-end, complete the following task in interface configuration mode:
| Task | Command |
|---|---|
| Set the speed to be used for incoming calls recognized as not ISDN end-to-end. | isdn not-end-to-end {56 | 64} |
Sometimes a router attempts to dial a call on an ISDN B channel before a previous, failed call is completely torn down. The fast rollover fails because the second call is made to a different number before the B-channel is released from the unsuccessful call. This might occur in ISDN configurations where:
You need to configure this delay if a BRI on a remote peer has two phone numbers configured one for each B-channel, you are dialing into this BRI, you have a dialer map for each phone number, and the first call succeeds but a second call fails with no channel available.
To configure a fast rollover delay, complete the following task in interface configuration mode:
| Task | Command |
|---|---|
| Define a fast rollover delay. | isdn fast-rollover-delay seconds |
A delay of 5 seconds should cover most cases. Configure sufficient delay to make sure the ISDN RELEASE_COMPLETE message has been sent or received before making the fast rollover call. Use the debug isdn q931 command to display this information.
This pattern of failed second calls is a rare occurrence.
In some geographic locations, such as Hong Kong and Taiwan, ISDN switches require that the Sending Complete information element be included in the outgoing Setup message to indicate that the entire number is included. This information element is not required in other locations.
To configure the interface to include the Sending Complete information element in the outgoing call Setup message, complete the following task in interface configuration mode:
| Task | Command |
|---|---|
| Include the Sending Complete information element in the outgoing call Setup message. | isdn sending-complete |
To test the router's ISDN configuration, we suggest that you perform the following tasks:
| Task | Command |
|---|---|
| Check Layer 1 (physical layer) of the BRI. | show controllers bri number |
| Check Layer 2 (data link layer). | debug q921 |
| Check Layer 3 (network layer). | debug isdn events |
See the Debug Command Reference for information about the debug commands.
Use the following commands to monitor and maintain ISDN interfaces:
| Task | Command |
|---|---|
| Display information about the physical attributes of the ISDN BRI B and D channels. | show interfaces bri number show interfaces bri slot/port (Cisco 7200 series) |
| Display protocol information about the ISDN B and D channels. | show controllers bri number how controllers bri slot/port (Cisco 7200 series) |
| Display information about calls, history, memory, status, and Layer 2 and Layer 3 timers. | show isdn {active | history | memory | status | timers} |
| Obtain general diagnostic information about the specified interface. | show dialer interface bri number |
This section provides the following ISDN BRI configuration examples:
The following example provides a simple partial configuration of a BRI interface that is connected to a PBX. This interface is connected to a switch that uses SPID numbers.
interface BRI0 description connected to pbx line 61885 ip address 7.1.1.3 255.255.255.0 encapsulation ppp isdn spid1 123 dialer map ip 7.1.1.1 name oldie 61886 dialer map ip 7.1.1.2 name rudder 61884 dialer map ip 7.1.1.4 name seinfeld 61888 dialer-group 1 no fair-queue ppp authentication chap
The following example enables Multilink PPP on BRI 0:
interface BRI0 description Enables PPP Multilink on BRI 0 ip address 7.1.1.1 255.255.255.0 encapsulation ppp dialer map ip 7.1.1.2 name starbuck 14195291357 dialer map ip 7.1.1.3 name roaster speed 56 14098759854 ppp authentication chap ppp multilink dialer-group 1
The following example configures BRI interfaces to connect into a rotary group (dialer-group) and then configures a dialer interface for that dialer-group. This configuration permits IP packets to trigger calls.
interface BRI 0 description connected into a rotary group encapsulation ppp dialer rotary-group 1 interface BRI 1 no ip address encapsulation ppp dialer rotary-group 1 interface BRI 2 encapsulation ppp dialer rotary-group 1 interface BRI 3 no ip address encapsulation ppp dialer rotary-group 1 interface BRI 4 encapsulation ppp dialer rotary-group 1 interface Dialer 0 description Dialer group controlling the BRIs ip address 8.1.1.1 255.255.255.0 encapsulation ppp dialer map ip 8.1.1.2 name angus 14802616900 dialer-group 1 ppp authentication chap dialer-list 1 protocol ip permit
The following example enables predictor compression on BRI 0:
interface BRI0 description Enables predictor compression on BRI 0 ip address 7.1.1.1 255.255.255.0 encapsulation ppp dialer map ip 7.1.1.2 name starbuck 14195291357 compress predictor ppp authentication chap dialer-group 1
The following example enables Stacker compression on BRI 0:
interface BRI0 description Enables stac compression on BRI 0 ip address 7.1.1.1 255.255.255.0 encapsulation ppp dialer map ip 7.1.1.2 name starbuck 14195291357 compress stac ppp authentication chap dialer-group 1
The following example enables PPP Multilink and Stacker compression on BRI 0:
interface BRI0 description Enables PPP Multilink and stac compression on BRI 0 ip address 7.1.1.1 255.255.255.0 encapsulation ppp dialer map ip 7.1.1.2 name starbuck 14195291357 ppp authentication chap compress stac ppp multilink dialer-group 1
The following example allows incoming voice calls to be answered on BRI 0:
interface bri0 description Allows incoming voice calls to be answered on BRI 0 ip address 7.1.1.1 255.255.255.0 encapsulation ppp isdn incoming-voice data dialer map ip 7.1.1.2 name starstruck 14038182344 ppp authentication chap dialer-group 1
The following example places an outgoing call as a voice call on BRI 1:
interface bri1 description Places an outgoing call as a voice call on BRI 1 ip address 9.1.1.1 255.255.255.0 encapsulation ppp dialer map ip 9.1.1.2 name angus class calltype 19091238877 ppp authentication chap dialer-group 1 map-class dialer calltype dialer voice-call
|
|