>>6XX behaviour is really painful.
>>I realy wonder why they break serail forking:

To me, 6xx means the user you're trying to reach doesn't exist anywhere
or won't accept your call anywhere or can't accept your call anywhere.
So, it doesn't matter if you try another fork because it won't work
anyway.

4xx however, (usually) means that the problem is localised at or near to
the endpoint that you're trying to reach.  So if you fail on one fork,
you can try another.

Now, it could be that an endpoint is sending a 6xx response when it
should only be a 4xx (but that's another issue).

Regards,

Attila




-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Iñaki Baz 
Castillo
Sent: 03 June 2008 08:41
To: [email protected]
Subject: [Sip-implementors] Why does 6XX break a serial forking?

Hi, IMHO 6XX behaviour is really painful. I realy wonder why they break serail
forking:

* Cool behaviour (with no 6XX):
- A calls B via their proxy.
- Proxy does parallel forking and 4 instances of B ring.
- All of them reply a 4XX (Busy, Not available...).
- Then the proxy generates a new branch for the INVITE and sends it to the 
voicemail server.

* Painful behaviour (using 6XX):
- A calls B via their proxy.
- Proxy does parallel forking and 4 instances of B ring.
- 3 instances reply a 4XX and the other replies a 6XX.
- The proxy has received a 6XX so it MUST NOT create a new branch to forward 
the request to the voicemail server !!!


 RFC3261

   6 Definitions:

      Sequential Search: In a sequential search, a proxy server attempts
         each contact address in sequence, proceeding to the next one
         only after the previous has generated a final response.  A 2xx
         or 6xx class final response always terminates a sequential
         search.


Isn't it painful?



-- 
Iñaki Baz Castillo
[EMAIL PROTECTED]

_______________________________________________
Sip-implementors mailing list
[email protected]
https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors

_______________________________________________
Sip-implementors mailing list
[email protected]
https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors

Reply via email to