Avaya to asterisk, incoming call with no audio


I have setup a h323 trunk between asterisk and avaya. Everything works fine but I realized this morning that one problem is still to be resolved. On Avaya side, I have 2 avaya definity switch both on different networks(, Trunk is setup between and Asterisk. When a call is made from a phone connected on to avaya, there is no audio. If a call from asterisk to a phone on, there are some audio. What can cause that? from where should I start?

Thanks for your help!

Are you doing SIP to H323??

it is H.323. I t is working now but I think it is my understanding of the system. I tougth that when a call was going from Avaya to asterisk, everything was going trought the H.323 trunk. The problem was coming from another switch, another site. From that site, we couldn’t see the Asterisk pbx. Here’s the setup that I have

Avaya Definity1 ----> Avaya Definity2 -----> Asterisk PBX
Remote site MPLS H.323

From switch 2, no problem at all, from one ,was working on one way only. When I’ve setup routes so that Avaya Definity1 could see Asterisk PBX, it start working but my understanding was that because going trought Avaya Definity2, it didn’t matter it Avaya Definirt1 couldn’t see Asterisk PBX.