[Asterisk-Users] Update: Welltech Wellgate 3504A registration problem

Dinesh Nair dinesh at alphaque.com
Tue Sep 21 00:41:33 MST 2004


On 21/09/2004 15:07 Leo Ann Boon said the following:
> I've just gotten the box to register all 4-ports with an external SIP 
> provider. The provider is running an old release of Broadsoft backend. 
> Seems like Broadsoft supports this strange way of authentication.

the 3504As do work with welltech's SIP proxy servers as well.

i checked the authentication code in chan_sip.c, and discovered that 
asterisk keeps track of the nonce (aka md5 hashed token) it sends out to 
registering users. when the users resend the register packet with the auth 
credentials, asterisk uses the Call-ID (or Call-ID and tag attribute if 
pedantic=yes) to match the second register packet with it's kept state to 
get the nonce it sent out the first time.

according to the RFC, different SIP users should be using different 
Call-IDs. as each of the 3504A's FXS ports register individually, they thus 
should be using different Call-IDs, however they don't but rather reuse the 
same Call-IDs. this is the behaviour which confuses asterisk as the 
wellgate registers.

(like i mentioned before, this is based on my reading of the RFC. i'm no 
SIP guru, so i may well be wrong in this analysis)

-- 
Regards,                           /\_/\   "All dogs go to heaven."
dinesh at alphaque.com                (0 0)    http://www.alphaque.com/
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