Dial out from local channel always congested

I am running Asterisk 1.2.6.15 rc1 in a centos VM configured with IAX2 trunks in a hosted environment.

I can successfully make outgoing calls dialing out on an IAX2 trunk directly.

However, if I dial a local channel first and then make an identical dial to an external trunk from the local channel context I always get congested. I have tried with and without the password added to the dial string but still get CONGSTN.

The call trace on the failing call attempt gives:

  1. AUTHREQ-AUTHREP
  2. ACCEPT
  3. ACK
  4. CONGSTN

The hosting provider has disabled call optimization / call transfers. I am wondering if this is the reason behind the local channel dials always failing :question:

Also the call trace shows 2 differences between a successful non local channel dial and an unsuccessful local channel dial.

SUCCESS CALL | UNSUCCESSFUL LOCAL CHAN DIAL
====================+==============================
CALLING TRANSIT : 0 | CALLING TRANSIT : 1
ADSICPE : 2 | ADSICPE : 0

I’m wondering if these differences could explain the call failure :question: