I hope this is not an FAQ, I've tried searching the available info.
Using
Ser 0.8.12, Cisco AS5300 with IOS 12.3.6 & a ATA-186.
ATA-186 (behind NAT) -> SER -> AS5300
On the INVITE, we get:
10w6d: httpish_msg_process_network_msg: Content Length 261, Bytes Remaining 256 10w6d: HandleUdpSocketReads: SIP Message incomplete, trashed
If you are using Cisco NAT, I'd suggest sticking a sniffer either side of it and checking it's not trashing things. The default Cisco NAT helper, at least on some IOS versions, is less than helpful and trashes packets (specifically truncated SIP_INFO packets so that their content length is zero). This causes incomplete packets. Turning off nat-helper fixes this (it is on by default).
I havnt turned on anything specific, I've placed the 'public IP' in the Cisco ATA-186 config, but havnt turned on any other NAT features, either in SER or the AS5300 (I know that RTP might currently break) - and I just wanted to get the initial invite to work. Specifically, what do you think I should turn off?
Linus