RFC 3262, "Reliability of Provisional Responses in Session Initiation Protocol (SIP)", June 2002

Errata ID: 4603
Status: Verified
Type: Technical
Publication Format(s) : TEXT
Reported By: Christer Holmberg
Date Reported: 2016-01-25
Verifier Name: Ben Campbell
Date Verified: 2016-01-25

Section 4 says:

Once a reliable provisional response is received, retransmissions of
that response MUST be discarded.  A response is a retransmission when
its dialog ID, CSeq, and RSeq match the original response.  The UAC
MUST maintain a sequence number that indicates the most recently
received in-order reliable provisional response for the initial
request.  This sequence number MUST be maintained until a final
response is received for the initial request.  Its value MUST be
initialized to the RSeq header field in the first reliable
provisional response received for the initial request.

It should say:

Once a reliable provisional response is received, retransmissions of
that response MUST be discarded.  A response is a retransmission 
when its dialog ID, CSeq, and RSeq match the original response. The
UAC MUST maintain, independently for each dialog ID, a sequence
number that indicates the most recently received in-order reliable
provisional response for the initial request.  This sequence number
MUST be maintained until a final response is received for the
initial request. Its value MUST, for each dialog (or early dialog),
be initialized to the RSeq header field in the first reliable
provisional response associated with the dialog received for the
initial request.

Notes:

Verifier edit: I removed two commas around "associated with the dialog" from the last sentence of the corrected text.

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