>>But how could a UAS know that its proxy will want to forward the >>request to a voicemail system when receiving a negative reply?
More accurately, the UAS doesn't know if the destined user is available on another fork so it shouldn't send a 6xx response. >>Why should a 6XX destroy still not generated branches? (ok, because RC 3261 >>says it but...) Because 6xx means you cannot be successful so don't bother trying. It stops time being wasted on other forks. If you look at rfc 3261, the cases for 6xx usage are very clear (only relevant text included): 21.6.1 600 Busy Everywhere This status response is returned only if the client knows that no other end point (such as a voice mail system) will answer the request. Otherwise, 486 (Busy Here) should be returned. 21.6.2 603 Decline This status response is returned only if the client knows that no other end point will answer the request. 21.6.3 604 Does Not Exist Anywhere The server has authoritative information that the user indicated in the Request-URI does not exist anywhere. 21.6.4 606 Not Acceptable This status response is returned only if the client knows that no other end point will answer the request. In other words, a UA MUST NOT send a 6xx response unless it really knows that "no other end point will answer the request". So again, the problem is incorrect 6xx usage by UAs. The right thing, at the moment, is to reconfigure or fix the UAs. (Not always possible I know) Regards, Attila -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Iñaki Baz Castillo Sent: 03 June 2008 10:05 To: [email protected] Subject: Re: [Sip-implementors] Why does 6XX break a serial forking? El Tuesday 03 June 2008 10:22:19 Attila Sipos escribió: > >>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. But how could a UAS know that its proxy will want to forward the request to a voicemail system when receiving a negative reply? Why should a 6XX destroy still not generated branches? (ok, because RC 3261 says it but...) > Now, it could be that an endpoint is sending a 6xx response when it > should only be a 4xx (but that's another issue). The problem is that many UA's reply a 6XX instead of a 4XX :( Thanks. -- 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
