Cisco Systems 1700 manual Isdn Configuration Options, Snapshot Routing

Appendix D Ordering and Configuring an ISDN Line

Note SPIDs have significance only at the local-access ISDN interface. Every router that uses ISDN must be assigned SPIDs (if used by the service provider) by the service provider for that router.

When the router connects to the service provider’s central office ISDN switch, it sends the SPIDs to the switch. If the router is not configured with the correct SPIDs, it cannot place or receive calls. Use the isdn spid command to define the SPID and the LDN on the router for both ISDN BRI B channels, as follows:

Router(config-if)# isdn spid1 spid-number[ldn]

Router(config-if)# isdn spid2 spid-number[ldn]

Note Although the LDN is usually optional, it might be required so that the router answers calls made to the second directory number.

ISDN Configuration Options

For information on how to configure Cisco 1700 router to dial into a central-site router over ISDN, refer to the Cisco 1700 Router Software Configuration Guide that came with your router.

For more advanced information on configuring ISDN for Cisco 1700 routers, refer to the chapter “Configuring ISDN” in the Dial Solutions Configuration Guide publication, which is on Cisco.com. This document includes information on the following topics:

Snapshot Routing

You can also configure snapshot routing for the router ISDN interface. During snapshot routing, the router is configured to bring up the ISDN line, dynamically learn about remote routes, and then take down ISDN line. The router saves the learned routes for a specified period of time, even though routing updates are not exchanged while the ISDN line is down. See the chapter “Configuring DDR” in the Wide-Area Networking Configuration Guide publication for detailed information about snapshot routing.

	Cisco 1700 Router Hardware Installation Guide
78-5405-03		D-5