A client switched to SIP telephony on thier UC520. The first day everything worked fine, the second day incoming call's did'nt come through. After a reload the trunks became registered again and calls started coming in. After thier lunchbreak (when the phones had'nt been used for a while) Incoming call's once again failed until someone made a outgoing call.
The SIP services provider claims the UC is'nt recieving the packages sent and that they are probably dropped by the internal firewall.
The UC:s wan interface is connected to a public ip with nothing in the way and the SIP trunk is configured using the CCA. I've lowered the firewall to "low" setting.
I've configured several UC:s with this sp before but not with the latest software release and CCA 2.2.2 so I wonder if there's some change in what CCA does to the access-lists after a trunk is configured?
Any help or ideas are greatly appreciated.
RJ - take a look at the link below to see if it gives you any pointers:
Markus - can you gather a log and post back on the community for when calls fail inbound along with a configuration (Pvt Msg me if you do not want share config on community) - check doc below for how to gather logs:
- Also, does this work if you make an outbound call first and then make an inbound call?
- Do the SIP registrations stay up all the time per below:
Potentially customer UC500 is deployed under a NAT router (please confirm). What is probably happening is that router is closing the SIP UDP ports after some inactivity time (15-30 sec in most of routers) so incoming SIP messages cannot pass in anylonger.
Check the router (I suspect it is not a Cisco one - No ALG), and create call forward rules for the SIP ports towards UC500.
Hope this helps.