One way audio on outgoing calls only

I have freepbx 2.5.1.1 Asterisk 1.6 CentOS 4.7

I have opened ports 5060 and 10001-20000 on the router and in shorewall.

when I make a call from my avaya handset to freepbx I get two way audio with no problems.

When I make a call from my freepbx handset to the avaya I get audio from the freepbx to the avaya but not from the avaya to freepbx.

I thought it was a firewall issue but after ressetting both the Zyxel and Shorewall I cant see a problem with the routing. Also getting two way audio with an incoming call surely shows the ports to be open.

Does anybody have any thoughts on this one?

I am assuming that the Avaya phone is outside your network and crossing NAT to get back in. If that is so, have you made the necessary additions to the sip_nat.conf file?

Yes the Avaya is totally seperate to the FreePBX system my sip_nat.conf is below:

externip=0.0.0.0
localnet=0.0.0.0/255.255.255.0
nat=yes

Obviously I have my external ip and localnet (gateway/router) ip in there.

When in doubt I normally open UDP ports 5002~5082 and 10000~20000 for testing. If that works, then I back SIP ports down to 5060~5082. You could try to open UDP 10000~64000 --> I have seen some odd vendor interconnect issues and that might help…

The localnet= line should not point to a gateway or router. It should be standard subnet notatation. i.e. if your local subnet is 192.168.17.x with a 255.255.255.0 (class C or /24 network mask) it should look like localnet=192.168.17.0/255.255.255.0. defining it by using a specific IP in the middle of the subnet range has in the past caused strange problems and since you are using the asterisk 1.6 it is totally possible that they have again become picky again.