Problems with IAX2 since 1.4.21.2

Hi!

We’re using IAX2 to establish a trunk connection between our proprietary system and an Asterisk server. However since Asterisk version 1.4.21.2, which fixed the “IAX POKE resource exhaustion” (AST-2008-10), we’re having troubles using POKE requests.

I am aware that the fixes incorporated in 1.4.21.2 include a change in the call number usage for POKE requests (call number 1). However when sending a POKE from our system to the Asterisk server with destination caller ID 0 we do get a PONG in return from caller ID 1. The problem is that Asterisk does not increase the Inbound Stream Sequence Number from 0 to 1 when responding with a PONG. As a result we run into a timeout after three unsuccessful tries. An ACK would be sent by our system only if the ISeqNo is also increased to 1 in the PONG.

My question now is: Is this really a wanted behaviour? According to IAX2 Draft 4 (tools.ietf.org/html/draft-guy-iax-04) i would conclude that this issue is a new bug resulting from AST-2008-10.
Please correct me if I’m wrong. It would be important for us to clarify that point since we have to know whether the “error” is on our side of the IAX2 connection or on the Asterisk side.