Hello! I'm new to Asterisk and also new to the forum. I'm here to ask about a problem we are facing at work, hope you can give me some heads up on how to deal with this. We have an Avaya system on which we have connection to the PSTN. We have established a H323 trunk between Asterisk and Avaya and we can call from our SIP clients on the Asterisk side to the Avaya phones and the other way around. All that works good. The problem is that if we try to call to an external number (external meaning a number of the PSTN side) from the Asterisk, the SIP phone can hear the voice comming from the outside but on the external side there's no audio. I don't know why there's only one way audio. Here are the contents of the configuration files: sip.conf ooh323.conf extensions.conf Hope you can help me solve this problem. Thank you!