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Route SIP REFER to SIP Trunk based on DN

John Biggs
Level 1
Level 1

Cisco UCM 9 is connected to a third-party PBX over SIP Trunk. Third-party PBX sends a SIP REFER message to Cisco UCM to call a DN on the third-party PBX. Cisco UCM responds with SIP 404 Not Found as it does not recognize the DN of the third-party PBX.


How do I configure Cisco Unified Communication Manager 9 to route this call back out over the SIP Trunk to the third-party PBX based on the DN (Not IP)?


Cisco UCM contains a route pattern 53xxx to route to SIP_Trunk_3rdParty.


Third-party PBX contains a SIP Proxy and Call Server. The call should route to the SIP Proxy IP. The SIP REFER contains "Refer-To" 53xxx@ThirdPartyCallServerIP

I added a SIP Route Pattern on CUCM to route calls for ThirdPartyCallServerIP to SIP_Trunk_3rdParty. This works in routing the call to ThirdPartyCallServerIP, however I need the call to route to 53xxx@ThirdPartySIPproxyIP for it to be successful.


Direct calls from CUCM to ThirdParty PBX 53XXX@ThirdPartySIPproxyIP are successful. SIP REFER coming into CUCM to request CUCM to call ThirdParty fail.

Any ideas on what configuration on CUCM I could try to get CUCM to route the call to thrid-party based on the SIP REFER?


6 Replies 6

Vivek Batra
VIP Alumni
VIP Alumni


I wanted to check this in my setup before suggesting you but I couldn't. 

Please check if <<Out-of-Dialog Refer Calling Search Space>> parameter on respective SIP trunk is assigned relevant CSS which has access to partition having 53XXX route pattern.



Thanks for the reply Vivek.


     -  ThirdPartyPBX

     -  CiscoEndpoints

Calling Search Space: "ThirdParty_Cisco" contain both of the above partitions.


Route Pattern 531XX and 80965 are assigned to Route Partition "ThirdPartyPBX"

Cisco UCM Main site phones are in CSS "ThirdParty_Cisco" and DN is in Route Partition "CiscoEndpoints". DN is in CSS "ThirdParty_Cisco".


Trunk "SIP_Trunk_3rdParty"  - Inbound and Outbound Calls are in CSS "ThirdParty_Cisco".

Trunk SIP information has "Rerouting CSS", "Out-of-Dialog Refer CSS", and Subscribe CSS as "ThirdParty_Cisco".

Cisco continues to respond to with SIP 404 not found. CUCM does not seem to match the SIP refer to the CSS or Route partition with with 531XX route pattern.

The SIP Refer is coming from DN 80965 over the SIP Trunk from the Third-party PBX.

Perhaps I'm missing something in my CSS config?

Any other method for CUCM to match SIP Refer to a Route Pattern?



Did you find a solution for the issue?  Having similar.

Hi Tony/John,

If you are getting NOTIFY with 404 Not Found (for REFER), I suggest you to cross verify Re-Routing CSS on SIP Trunk and it must have access to desired route pattern partition.

- Vivek

Hey Tony/John,

I had a similar issue connecting to Genesys GVP.  

This issue was that the refer comes into CUCM as URI format, <DN>@<IP>.  I had to add a SIP Route Pattern to point their IP to the SIP trunk/RL.

After that, refers worked normally. 

Thanks for posting this Ervin. Different product, but same issue. This is what I needed to deal with the SIP Refer.