Subject: SIP question -- are 6xx responses really provisional??

From: "Scott Petrack"<[email-masked]>
Date: Wed, 6 May 1998 16:29:13 +0200

SCOTT PETRACK @
                                 VOCALTEC
                             05/06/98 04:29 PM
               (Embedded image moved to file: PIC23439.PCX)

Here are three quotations from SIP v5:

>6xx responses indicate that a server has definitive information about   a
particular >user, not just the particular instance indicated in the
Request-URI. All further >searches for this user are doomed to failure
and pending searches SHOULD be >terminated.

>All 1xx and 6xx responses are provisional. Other responses are
>considered final.

>If the response is provisional, the initiating client MUST continue
retransmitting >the request, albeit less frequently, using timer T2.   The
default retransmission >interval T2 is 5 seconds.

1. First the "600    BUSY"  Response.
If the response is provisional and contains a "Retry-After" field, in this
case surely the client should try at the time listed in the Retry-After
field. If this is listed in 20 minutes, the client should not retransmitt
the request in after timer T2, right?
And is it really forbidden for the client not to retransmit the request?
This is a bit wierd. If the callee returns BUSY, it's not allowed for the
Caller  to give up?  According to the letter of the spec the caller can't
even send BYE.  (If the caller sends BYE the s/he is not retransmitting the
request, which s/he MUST do.)

Here it would be ok to say that the initiating client MAY continue
retransmitting the request or MAY send a BYE to terminate.

2. And how about the "provisional responses"   "604 Does not exist
anywhere" or "603 Decline." These responses sound pretty final to me. But
yet the client must retransmit the request?  I think that the three parts
of the spec quoted above imply:

1.The server has definitive information that the user does not exist
anywhere.
2. The client must retransmit the request after a default of 5 seconds.

Thanks,
Scott

Scott

Scott Petrack
VocalTec Communications Ltd.
[email-masked]

---

From: Eric Tremblay <[email-masked]>
Date: Wed, 6 May 1998 14:38:38 -0400

Scott, 

The latest *working* draft v5 fixes that.  
Only 1xx responses are provisional

You can download the latest working draft from Mr. Schulzrinne SIP page
http://www.cs.columbia.edu/~hgs/sip/