Configuration for converting PRI to SIP on 2911 Gateway

[Matthew.Diioia]

I have a client who is slowly migrating to a Cisco UC environment, but is only willing to upgrade certain pieces of infrastructure at this time. I'm looking for assistance with configuring a Cisco 2911 to convert a T1/PRI connection to SIP for a handoff to Microsoft Exchange. The general "diagram" is listed below.

Voicemail<- - - - - -> MS Exchange 2010 < - - - - - SIP - - - - - > Cisco 2911 < - - - - - PRI/T1 - - - - - -> Nortel PBX<- - - - - - >PSTN

At this time, I am only concerned about the Cisco 2911 configuration. The PBX will provide a T1/PRI connection, and MS Exchange will have a dedicated IP address.

Any help is appreciated.

[Jonathan Schulenberg]

This is actually pretty simple. You do not need to configure CUBE or the SIP UA for this as it can be done just with a few dial peers.

The incoming VoIP dial peer would look like this:

dial-peer voice 2 voip
 description INCOMING VoIP
 voice-class codec 1
 session protocol sipv2
 session transport tcp
 incoming called-number .
 dtmf-relay rtp-nte
 no vad

The VoIP dial peer to Exchange would look similar to this:

dial-peer voice 10 voip

description OUTGOING to Exchange

destination-pattern

monitor probe icmp-ping   <-- Optional; takes the dial-peer down if Exchange stops responding.

voice-class codec 1

session protocol sipv2

session target ipv4:

session transport tcp

dtmf-relay rtp-nte

no vad

And of course you would need the dial-peer appropriate for the POTS side. IOS interops between SIP and ISDN quite well.

The only thing I have not tested is how ISDN RDNIS would map to the Diversion header on SIP.