SIP failover problem

[dpuntaric]

Hi guys!

I have a problem and here is what happens...

I have CUCM 8.6.2 and two SIP trunks to 3825 CUBEs, CUBEs have SIP link to provider. Each SIP trunk on CUCM is set to separate RouteGroup, and I put them to one RouteList.

Problem occurs when I make a call, call goes through first SIP trunk (INVITE) to CUBE, CUBE does INVITE to provider, provider responds with SIP 603 message and CUBE sends SIP 403 to CUCM. That is one problem. Why CUBE does not send same SIP message to CUCM as it got from provider?

Second problem is that CUCM then sends INVITE do second CUBE (which is understandable since both are in same route list), second CUBE sends INVITE to provider, but provider does not respond because while primary link is up, secondary will not respond. Now there is no response from provider on second link and session timeout kicks in. This is not good for me, because the application that is behind CUCM needs correct codes why the call did not go through, and I need CUCM to send correct error code to that application behind it.

Is there a way to keep link failover in case of fail of first link, but not to send SIP INVITE through second CUBE while there is any kind of response from first link?

Thank you in advance for any ideas!

Best regards,

Darijo

[btmulgrew]

Hi Darijo - Can you provide IOS ver on your CUBE please?

Also, just a query when you say "but provider does not respond because while primary link is up, secondary will not respond" - does this mean you would not be able to route out CUBE 2 if the uplink to CUBE 1 on your internal LAN failed?

Cheers

Brian

[dpuntaric]

Hi!

IOS on CUBE is c3825-advipservicesk9-mz.124-24.T4

From my CUBE to providers router there is a point to point link (/30). I put on my CUBE static route to same IP address that is SIP gateway, and that route points to other end of that point ot point link.

From first CUBE I can ping other side of ptp link and providers SIP gateway, and from secondary CUBE I can ping other side of ptp link, but not provider SIP gateway.

Provider SIP gateway on both CUBEs is of course same IP address, but while primary link is up (I can ping SIP gateway from first CUBE) I cannot ping it from second CUBE.

And yes, I would not be able to route to secondary CUBE if my primary CUBE fails. But locally there are two IP links to my LAN frome each CUBE.

Thanks!

BR,

Darijo