One of the applications most used is DDR ISDN (telephone call routing on demand) to be able to send traffic when the router deems interesting. DDR allows two or more routers to connect installations, conventional analog dial as needed. DDR normally used for casual connections, such as telecommuters, small offices, customers, etc.
Configuring DDR
The DDR configuration process defined in the following steps:
1. Define static routes
2. Specify interesting traffic
3. Configure the dialing information
Define a static route to the destination:
Router (config) # ip route [destination network address + mask] [next hop address / output interface] [admin distance.] [Permanent]
Define the interesting traffic, and associate it with an access list to specify in more detail the protocol data, such as port number:
Router (config) # dialer-list [group-bearing (1-10)] protocol [Protocol Type] [permit / deny / list access list number]
Router (config) # access-list [number] [permit / deny] [protocol] Any Any eq [port]
Configure the interface to the routing information, encapsulation, authentication, and link the interface to define interesting traffic list:
Router (config-if) # ip address [IP address]
Router (config-if) # encapsulation PPP
Router (config-if) # ppp authentication chap
Router (config-if) # dialer-group [group-bearing (1-10)]
Verifying ISDN, DDR:
Show isdn status
Sample statistics.
Show isdn active
Displays a call and your process.
Show dialer
It offers general diagnostic information.
Debug isdn q921
Check the connection to the ISDN switch.
Debug isdn Q931
Displays the call and connection messages.
Debug dialer [event / packets]
Display detailed information like number of the interface.