SIP Trunk to Trunk 1-Way Audio

Joined: Sun 01 of Jul, 2012

SIP Trunk to Trunk 1-Way Audio

Posted:Sun 01 of Jul, 2012 (02:29 UTC)
Hey All,

Just installed Trixbox and it's working fine internally, but having an issue described below.

1. CELL PHONE A calls into SIP trunk and hits INSIDE PHONE A and it works. Same the other direction.
2. CELL PHONE A calls into SIP trunk and hits INSIDE PHONE A which is forwarded to CELL PHONE B and I get one way audio as well as see RTP stream blocked by FortiGate firewall because it is not associating a policy to it which in turn is blocking the RTP stream.

I am using the ALG on the FortiGate with sip-helper disabled and tried it the other way as well using sip-helper without using the ALG and the problem persists. I have both the inbound and outbound policies created with the ALG although the outbound policy isn't used because it is matching it to the inbound wan->lan policy since the call is originating from WAN. I think the problem has something to do with the traffic coming into the Fortigate bouncing off the PBX the back out the FortiGate since the call is forwarded outbound and the firewall is unable to process the second two-way RTP stream. If I am calling from CELL PHONE A I can hear the person the call was forwarded too CELL PHONE B, but they can't hear me. Which would indicate that CELL PHONE A's OUTBOUND RTP stream is being blocked disassociated with the RTP pinholes that the ALG is opening up for the SIP session's. Any ideas here? Thanks in advance.