The Challenge

I was asked to integrate a CUBE gateway with a UK Service Provider using SIP. Considering a CUBE SIP integration was a task I had performed many times with service providers in the US, I thought it would be a walk in the park. Unfortunately, I was mistaken.

I knew from my previous integrations in the US that Cisco publishes their supported configurations for service providers, however this is not the case in the UK as you can see by clicking here.

When I first had a look at the configuration I noticed there were several commands missing like the realm and the UDP port ranges. Without this crucial information, configuration would have been impossible. After an hour I was able to attain the information I needed. This was a simple task but became quite time consuming and therefore I’m posting this article to help anyone else, should they run into this issue.

The Solution

I did manage to get everything resolved in the end and below is the workable configuration that you need to use to register a sip trunk to a service provider in the UK.

Note this is registering the CUBE Public IP address to the Service Provider SIP Network.

Config

sip-ua

 credentials number 44[UK Number] username  [UK Number] password  XXXXXXXXXXX realm XX.XXXXXXX

 authentication username [UK Number]  password  XXXXXXXXXXX realm XX.XXXXXXX

 no remote-party-id

 set pstn-cause 47 sip-status 486

 retry invite 2

 retry response 3

 retry bye 1

 retry prack 6

 timers expires 60000

 timers connect 1000

 registrar dns:XX.XX.XXXXXXX.co.uk:5060 expires 3600

 sip-server dns: XX.XX.XXXXXXX.co.uk:5060

 reason-header override

 connection-reuse

 host-registrar

Verification

 

Noname#show sip-ua register status

Line                             peer       expires(sec) reg survival P-Associ-URI

================================ ========== ============ === ======== ============

[UK Number]                                                 YES

So what’s the lesson to take away from this? When you are performing a CUBE SIP integration you need to always make sure you state the realm and you explicitly specify the UDP port range after the register dns and sip server dns commands above. This is because the service provider will not tell you to add any of these commands. So when your CUBE doesn’t register, the service provider will just say it’s probably a firewall issue when clearly you were given a generic configuration that’s not necessarily compatible with Cisco. So make sure you add the realm and state the UDP port ranges mentioned above.

Dylan James is a Senior Collaboration Architect at Tesrex. He is a CCIE qualified engineer with an IT career spanning over 11 years. He specialises in Collaboration, Mobility and Remote Access.