Cisco IOS Dial-Peers: 11 digit dialing and International dialing

The next dial-peer example is used to route 11-digit long distance dialing for providers that require 11 digits to route long distance calls. Dial-peer voice 203 pots Destination-pattern 91[2-9]..[2-9]…… Prefix 1 Port 0/0/0:23 Dial-peer 203 includes the prefix 1 digit manipulation option to ensure 11 digits are sent to the PSTN provider. The forward-digits 11 command can be used in place of the prefix 1 command. AT&T circuits normally require 10 digits instead of 11. The following dial-peer would ensure that only 10 digits are sent to the provider: Dial-peer voice 203 pots Destination-pattern 91[2-9]..[2-9]…… Port 0/0/0:23 Notice the prefix 1 command was removed from the dial-peer. The forward-digits 10 command can be added to dial-peer 203, but the default digit stripping rule would ensure that 10 digits are forwarded to the AT&T PRI circuit. The next dial-peer example is used for International dialing: Dial-peer voice 204 pots Destination-pattern 9011T Prefix 011 Port 0/0/0:23 The prefix 011 digit manipulation command is the only option available on this dial-peer. International dial plans are variable length. If the goal is to allow International calls anywhere, dial-peer 204 meets this objective. If the goal of the deployment was to allow International calls only to the UK, the dial-peer would be modified as follows: Dial-peer voice 204 pots Destination-pattern 901144T Prefix 01144 Port 0/0/0:23 The modified dial-peer 204 includes the UK country code of 44, but no other country codes. Since the router does not know how many digits the “T” wildcard character will match against, the router must wait for the T.302 inter-digit timeout to expire before routing the call. The T.302 timeout is 10 seconds by default in the router. The inter-digit timeout can be terminated by dialing the pound “#” symbol on the DTMF keypad of the phone. The Cisco router implicitly understands that the # symbol is used to terminate the inter-digits timeout. We have now completed the coverage of an outbound PSTN dial-plan on a Cisco IOS based router. Each call on the Cisco router involves an inbound and outbound call leg. If calls were coming from CUCM and being routed through the gateway, the inbound dial-peer would be a Voice over IP dial-peer. There is a hierarchy to matching inbound dial-peers that we will explore in the next blog.

Join the Network World communities on Facebook and LinkedIn to comment on topics that are top of mind.
Must read: 10 new UI features coming to Windows 10