Re: [Sipping] 答复: RE: RE: non-200 response to PRACK

["Christer Holmberg" <christer.holmberg at ericsson.com>]

Hi,

	
	>>At least we decided during an IETF meeting that it should be allowed
	>>to reject a PRACK SDP offer using a 4xx response. I think we then 
	>>later on the list realized that a PRACK can be rejected for other 
	>>reasons also.
	> 
	>[Gao] If UAC(of PRACK) is introspective enough(deducing from the *MUST* 2xx of UAS), I think there would be very infrequence of 4xx. 

I think 4xx already now is quite infrequent. But we still need to know how to deal with it when it happens.


	>I still think it is not obligatory modification, but a choice. 

What is?

	
	>And if someone find a case, in which we MUST using PRACK to do something rejectable, then it is a obligatory modification of RFC3262. 

I think at least Paul and Brett has indicated that there are cases when it is useful to be able to reject the PRACK.

Personally I think it's bad protocol design to say that one *MUST* send a 200 response - no matter what.


Regards,

Christer