SIP dial peers with multiple subs

[billmatthews]

Our Environment:
2921 Gateway Version 15.3(3)M3
Prime Collaboration Manager Version 10.6.0.1015
CUCM System version: 10.5.2.10000-5  (one pub, one sub)
Call Path: PSTN----PRI*---GW----SIP----CUCM

When I built my IOS PRI gateway, I only had one CUCM node (combined pub/sub).  I've now added a dedicated sub.  The phones all register to the sub.  When the phones are on the sub, inbound calls work fine, but outbound calls don't work.  I assume I just need a dial-peer.  

So my question is, how do set up the dial-peers? Do I need multiple dial-peers, pointing to each sub for failover?  Or just an outbound dial-peer?  Here's an example of my IOS config.  

sccp ccm 10.10.10.30 identifier 1 version 7.0 

!
dial-peer voice 61 voip
 destination-pattern ^2124474800
 session protocol sipv2
 session target ipv4:10.10.10.30
 dtmf-relay rtp-nte
 codec g711ulaw
 no vad

[Jaime Valencia · Accepted solution]

Did you add the new server to the ip trusted list on the ISR???

And you usually want to have several DPs for inbound calls, one for each server where you want to handle calls, and only one outbound would be necessary.

FYI, a single server is just a PUB, nothing else.

[billmatthews]

Thanks for the clarification, +5

I think I'm missing both those steps.  Can you tell me how to add the ip trusted list?

And for multiple inbound DPs, do I set a preference? Can you show me an example, or document?

Thanks!

[Jaime Valencia]

Yes, you set the preference for the DPs

http://www.cisco.com/c/en/us/support/docs/voice/call-routing-dial-plans/112083-tollfraud-ios.html

[Chris Deren · Accepted solution]

In addition of fixing trust list you need a dial-peer to use the sub as well, otherwise you have no redundancy, you can either build dedicated dial peer with different "preference", build local SRV record that balances the destinations and then on the dial-peer use "session target dns:", or if you have new IOS you can use server groups:

http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/dialpeer/configuration/15-mt/vd-15-mt-book/multiple-server-groups.html

Chris

[billmatthews]

Thanks.  Fixing the Trust List did indeed fix my outbound dialing problem.  And I'm reading about server groups.

But regarding my outbound calls, I notice something odd in the debugs.  On my ISR, when I run debugs, and place a call from a phone registered to my sub...all the SIP headers show the IP of the publisher.  I can't find a reference to the sub anywhere in the debug logs.  Is that normal?

I've confirmed the phone is registered to the sub.  

Thanks

[Chris Deren]

That means the call is coming from the pub which is probably the first server in the CUCM group assigned to the device pool that the SIP trunk is using or in case you are using "Route on All Nodes" (checkbox on the SIP trunk and route list) that would indicate that the phone making the call is registered to that server.  Your Sub should be listed as the first server in all CUCM Groups so make sure you adjust it.

[billmatthews]

Ahh yes indeed, that was it.  Thanks Chris!