Configuring Q.931 Support

Q.931 establishes and terminates ISDN circuits. This occurs at the network layer in the protocol stack. The basic steps to configure ISDN PRI with Q.931 are as follows:

1. Select the service provider ISDN PRI switch type:

   router(config)# isdn switch-type primary-net5 
   

2. Configure the ISDN T-1/E-1 controller by setting the time slots, which are used for a T-1. The range is 1–23:

   router(config)# controller {T-1 | E-1} slot/port
   router(config-controller)# pri-group timeslots range
   

3. Exit from the T-1/E-1 controller configuration mode:

   router(config-controller)# exit
   

4. Configure the ISDN D channel interface:

   router(config)# interface serial0/0:n
   

5. Configure the ISDN protocol as primary slave or the primary master:

   router(config)# isdn protocol-emulate {network | user}
   

6. Enable or disable power supplied from an NT configured port:

   router(config-if)# [no] line-power
   

7. Allow incoming voice calls:

   router(config-if)# isdn incoming-voice voice
   

Configuring CAS

source : http://simple-telecom.blogspot.com/