[AusNOG] Vocus Voice issues

[Ross Wheeler]

On Mon, 21 Nov 2016, Skeeve Stevens wrote:

> Symptoms:
>     - Call operates normally
>     - Call gets put on hold - works normally if under 45 seconds - can
> unhold and all works
>     - After 45sec, the audio in one direction stops

> Bit of head scratching... anyone seen this?

Silly question, but is it by any chance behind NAT?

I had a semi-similar issue a while ago, where the device doing NAT dropped 
sessions after an unreasonably short time. IIRC, in that instance - the 
ATA could initiate an outgoing call, but would not receive an incoming 
call. (Forcing a re-register would fix it, but only until the NAT entry 
expired again)

I suppose this could happen with a "stateful firewall", where the table 
allows return packets only after an outgoing packet, but expires with 
undue haste!

R.