[asterisk-dev] Problems with IAX2 since 1.4.21.2

[Tim Panton]

On 9 Sep 2008, at 14:47, Floimair Florian wrote:

> 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 (http://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.
>
> With best regards
>
> Florian Floimair
> Technical Support
>

Yep, sounds like a bug in asterisk. Here's the rule as I understand it:

"When you recieve any fullframe the recieved iseq tells you that the
transmitter has received _all_ the packets you sent with an oseq
less than this iseq. Any fullframes you have sent with oseqs greater  
than
or equal to the most recent received iseq are candidates for retries."


Tim.