Command Reference Guide Tunnel Configuration Command Set
61200510L1-35E Copyright © 2005 ADTRAN 1121
no shutdown
cross-conn ect 1 t1 1/1 1 ppp 1
ip address 10.1.1.1 255.255.255.252
dial-backup call-mode answer
dial-backup number 555-8888 analog ppp 2
!
interface ppp 2
description connection for remote 3200 dialin for backup
ip address 10.10.10.1 255.255.255.252
ppp authentication pap
username joe password pswrd
!
line telnet 0 4
password adtran
Usage Examples
The following exampl e configures the AOS to answer dia l-backup calls on this end point but never genera te
calls:
(config)#interface ppp 1
(config-ppp 1)#dial-backup call-mode answer-always
Technology Review
This technology review provides information regardin g specific dial-backup router behavior (i.e., when the
router will perform dial-backup, where in the configuration the AOS accesses specific routing information,
etc.):
Dialing Out
1. The AOS determines to place an outbound call when either the Layer 1 or Layer 2 has a failure.
2. When placing outbound calls, the AOS matches the number dialed to a PPP interface. This is
accomplished with an ad dition to the dial-backup number command (refer to dial-backup number

<digits> [analog | digital-56k | digital 64k] <isdn min chan> <isdn max chan> <interface> on page

1125).
3. When placing the call, the AOS uses the configuration of the related PPP interface for authentication
and IP negotiation.
4. If the call fails to connect on the first number dialed, the AOS places a call to the second number if
configured. The second number to be dialed references a separate PPP interface.
Dialing In
1. The AOS receives an inbound call on a physical interface.
2. Caller ID is used to match the dial-backup number command to the configured PPP interface.
3. If a match is found, the call connects and the AOS pulls down the primary connection if it is not already
in a down sta te.
4. If no match is found from Caller ID, the call is terminated.