Cisco 850 Series, Configuration Manual, Page: 134 / 196

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Cisco 850 Series and Cisco 870 Series Access Routers Software Configuration Guide
OL-5332-01
Chapter 13 Configuring Dial Backup and Remote Management
Configuring Dial Backup and Remote Management Through the ISDN S/T Port
Configuring Dial Backup and Remote Management Through the
ISDN S/T Port
Cisco 876 and Cisco 878 routers can use the ISDN S/T port for remote management. With an advanced
enterprise (c870-adventerprisek9-mz) image, a Cisco 876 router can also use the ISDN S/T port for
dial backup.
Figure 13-2 and Figure 13-3 show two typical network configurations used to provide remote
management access and backup for the primary WAN line. In Figure 13-2 , the dial backup link goes
through a customer premises equipment (CPE) splitter, a digital subscriber line access multiplexer
(DSLAM), and a central office (CO) splitter before connecting to the ISDN switch. In
Figure 13-3 , the
dial backup link goes directly from the Cisco router to the ISDN switch.
Figure 13-2 Dial Backup Through CPE Splitter, DSLAM, and CO Splitter
82892
ATM
network
Internet
B
2
3
4
8
7
6
5
C
A
1
1 Cisco 876 or Cisco 878 router A Primary DSL interface
2 DSLAM B Dial backup and remote management through the
ISDN interface (ISDN S/T port); serves as a
failover link when the primary line goes down
3
ATM aggregator
4 ISDN switch
5 ISDN C Administrator remote management through the
ISDN interface when the primary DSL link is
down; serves as dial-in access to allow changes or
updates to Cisco IOS configuration
6 ISDN peer router
7
Web server
8 Administrator — —