UC560 - SIP-Trunk - no incoming call

[support]

Hi,

a customer of me has a UC560 with one SIP-Trunk to a SIP-Provider.
a "show sip-ua register status" shows the SIP-Trunk as registered.

Everything works, but incoming calls.
Sometimes calls come in and sometimes not.

When I do a "debug ccsip message" and the call doesn't come in, I don't see any debug message - no messages appearing.

I think it isn't a firewall problem, because sometimes calls come in.

Has anyone an idea?

Thanks

Matthias

[Darren DeCroock]

Hello Matthias,

There are only two possiblities that I can think of.  First, the provider is not sending the invite to the correct IP, or the Invite is not getting to your UC500.  It could also be an issue with an ACL or the Toll Fraud App on the UC500.

Please run the following debugs, and make test calls until it fails.

   debug ccsip messages

   debug voice ccapi inout

Even if the call is hitting an ACL or the Toll Fraud App, we should see some activity with these debugs.  If you are still seeing nothing at all, I would get in touch with your SIP provider.

Thank you,

Darren

[support]

Hello Darren,

Thank you for your answer.

The SIP Provider told me, the connection between my UC and the Provider got disconnected.

I should use NAT keepalive with 15seconds.

In Cisco UC500 is no NAT keepalive, so I configured a "keepalive target dns:provider.com:Port" and a "timers keepalive 15"

It seems that this solved the problem.

regards

Matthias