This document covers the configuration procedures on how to route outgoing calls to PSTN Operator through ISDN using Specific Channels/timeslots in E1/T1.
Sometimes the Public Switched Telephone Network (PSTN) Telco wants the outgoing calls from VOIP network to be routed only through Specific ISDN Channels/timeslots in E1/T1.
Requirement/ Issue: When Extension 1002 makes outbound call, Call should go out through First 1-10 channels and when Extension 1003 makes call, channels 11-14 should be used. 1002 should not be able to use channels 11-14.
Sample Outgoing Call flow from VOIP Network to PSTN Network
Here is the solution with the configuration commands to route the outbound calls from VOIP Network to PSTN Operator through Specific ISDN Channels in E1/T1.
Restriction of outbound calls through Specific ISDN channels in E1/T1 is implemented using Dial-Peer Class of Restriction (COR) command in Cisco IOS gateway.
Following command needs to be issued on the Gateway:
controller E1 0/1/0
trunk-group first timeslots 1-10 trunk-group sec timeslots 11-14
dial-peer cor custom name 1002 name 1003
! --- Configure dial-peer cor custom and assign a meaningful name that specifies the way CORs (Class Of Restriction) apply to dial-peers
! dial-peer cor list 1002 member 1002
! --- Create the actual lists of the restrictions that apply to the dial-peer