[asterisk-dev] dialog matching

[Steve Murphy]

On Thu, 2007-12-20 at 10:17 +0100, Klaus Darilion wrote:
> Hi Steve!
> 
> pedantic in Asterisk is buggy - regardless if it is turned on or off.
> 
> Thus, please do not just reimplement the old behavior but fix it.
> 
> AFAIK pedantic controls 2 things:
>   1. accept short header names and header which are wrapped around 
> multiple lines if pedantic=on
>   2. use to-tag for dialog matching if pedantic=on.
> 
> IMO part 2 should be removed from pedantic setting and dialog matching 
> should be done standard conform.
> 
> Current problems with dialog matching with pedantic=off: Asterisk 
> accepts an to-tag. Thus for example a reINVITe will cause a new call if 
> Asterisk can not find an existing call -> bad security
> 
> Current problems with dialog matching with pedantic=on: Asterisk learns 
> the totag from the first provisional response and ignores responses with 
> different to-tag although they belong to the same transaction -> causes 
> problems if the outgoing SIP call is forked and causes multiple 
> early-dialog.
> 
> The fix would be to always use RFC conform dialog matching - meaning 
> call-id/fromtag/totag for indialog requests and accept multiple 
> provisional responses (I know asterisk can not handle multiple early 
> dialogs but a reasonable workaround would be to learn the totag only 
> from the final response, not from the provisional response and treat all 
> early dialog as one early dialog).
> 
> regards
> klaus
> 
> 

Klaus--

This is good input, but I'm not the right guy at this point to implement
your suggestions; If someone who **can** implement this would like to
collaborate with me to get a new scheme working without linear
searching, I'd be happy to help!

I'm hoping one of the sip gurus will jump in and give some feedback on
Klaus's suggestions....

In the meantime....

murf




-- 
Steve Murphy
Software Developer
Digium
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/x-pkcs7-signature
Size: 3227 bytes
Desc: not available
Url : http://lists.digium.com/pipermail/asterisk-dev/attachments/20071220/f9c59068/attachment.bin