SIP errors - UDP Fragmentation??
I'm running behind router Firmware: DD-WRT v24-sp2 (10/10/09) voip on a Linksys WRT-54G Version 2.
I'm running an asterisk pbx (Ubuntu Server 12.10) behind this router and I have ports 5000-31000 forwarded to the asterisk server. The asterisk server has a software firewall that only accepts traffic from our SIP providers IP range.
Okay, so until yesterday this worked perfectly, but then suddenly we noticed that a lot of calls were going straight to the Asterisk voicemail instead of ringing the phones.
I set up wireshark on the pbx and compared the good calls to the failed ones and noticed that the failed ones just show a lot of UDP packets from the SIP provider to high port numbers on the box, some of which were not even numeric (12502, 25741, "msgclnt", etc.) whereas the successful calls start with a SIP/SDP request to us from the SIP provider on port 5060.
The strange thing is that the failed calls do go to voicemail which is hosted on the pbx inside our network. Rebooting the router/pbx seems to temporarily fix the issue.
The only change on the pbx bow was that 2 days ago I installed tftp-hpa listening on port 69 to the LAN only.
Onieric - Leaning towards Xubuntu these days.