Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Attention: The Community will be in read-only mode on 12/14/2017 from 12:00 am pacific to 11:30 am.

During this time you will only be able to see content. Other interactions such as posting, replying to questions, or marking content as helpful will be disabled for few hours.

We apologize for the inconvenience while we perform important updates to the Community.

New Member

SIP-UA Registration to CUCM

Hello, All!

I'm working on a scenario in my lab and would like to know if it's possible to register a voice-enabled ISR as a SIP endpoint in CUCM. Rather than register the ISR as a trunk, I'd like to use SIP-UA to register a particular extension. Basically CUCM would be acting as the ITSP.

Inbound Call Path

PSTN --> Core ISR --> CUCM --> 2911 Registered with SIP-UA --(FXS Ports)--> Analog Phone


In CUCM I am seeing "Rejected" under the status. I have included the ISR debugs for "ccsip messages".

Steps taken so far..


Configured SIP Advanced device

     Added ext to line 1

     Set "Digest User" to "telecomsiptest"

User Configuration - telecomsiptest

     Set digest authentication password

     Associated device to user account


Configured SIP UA as seen below.


credentials username telecomsiptest password 7 XXXXX realm XXXX

authentication username telecomsiptest password 7 XXXXX

registrar 1 ipv4: expires 3600

registrar 2 ipv4: expires 3600

registrar 3 ipv4: expires 3600

sip-server ipv4:

Any help would be greatly appreciated as always. If there's a better way of doing this setup, I'm all ears. Thanks again for your time.

Everyone's tags (5)
Hall of Fame Super Gold

SIP-UA Registration to CUCM

There is not need to register. Configure the ISR as SIP trunk and that's it.

New Member

Re: SIP-UA Registration to CUCM

If I did that, would I not need to build a Route Pattern for inbound calls, which would then require I create a route list as well? If this was multipled times a 100 that starts becoming unmanageable when the end-goal is to just have 1 extension ring down to the router and back.

Perhaps I'm not thinking about it correctly. Here's the scenario...


2911 Router - CUBE Licensed, PVDM installed

4-Port FXS Card - I'd like to connect 4 lines to an analog 4-line phone system.

4-Port FXO Card - For POTS Failover on SIP failure


The SIP gateway would only need 1 extension sent to it, example x5000. When x5000 is called it should be passed down to the the SIP gateway and then start hunting on the 4 FXS ports.


All outbound traffic will be passed to CUCM for processing. If CUCM is unreachable, calls will be sent via a POTS line connected to 4-Port FXO card.

Have I completely overthought the design? I've dug so deep into this I feel like I may have looked over something much simpler. Thanks for your help!

New Member

Re: SIP-UA Registration to CUCM

Any additional thoughts on this? Thanks again for your insight.

Hello raymond00,Could you

Hello raymond00,

Could you finish your SIP Trunk configuration to ITSP? I have the same problem. I´m going to install a 2911 gateway to ITSP by SIP Trunk. This gateway will be registered on UCM. I want UCM hands all inbound and outbound calls. 

My topology: UCM > Trunk > Gateway > SIP Trunk > ITSP

Could you tell us your experience or your configuration file about it?

CreatePlease to create content