[Asterisk-Users] port forwarding ip to ip sip calls

[Wilson Pickett]

> I've got two pa1688 phones that I want to set up to communicate between
> branch offices without a gatekeeper. Both phones will be behind a
> firewall and I want to use port forwarding so the phones can communicate.

Are you using these phones with SIP? Why not try IAX2?
 
> I tested the phones behind a firewall on the same network segment and
> there were no problems at all using sip. However, I then moved the
> phones into  situ and port forwarded udp on 5060 and 10000 - 20000 at
> both branch offices firewalls. I set the rcp port to 10000 and the sip
> port to 5060. The phones were able to ring each other, however, there
> was no sound on both ends.
> 
> Can some one please tell me which ports I have to open in order to make
> communications between the two branch offices using these phones. Or
> share a config or suggest another protocol so I can make this happen.

Check for nat=yes and canreinvite=no in sip.conf