[Sip] [Technical Errata Reported] RFC3261 (2910)

[RFC Errata System <[e-mail]>]

The following errata report has been submitted for RFC3261,
"SIP: Session Initiation Protocol".

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You may review the report below and at:
http://www.rfc-editor.org/errata_search.php?rfc=3261&eid=2910

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Type: Technical
Reported by: Iñaki Baz Castillo <[e-mail]>

Section: Table 2

Original Text
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      Header field          where   proxy ACK BYE CAN INV OPT REG
      ___________________________________________________________
      Contact                1xx           -   -   -   o   -   -

Corrected Text
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      Header field          where   proxy ACK BYE CAN INV OPT REG
      ___________________________________________________________
      Contact                1xx           -   -   -   m   -   -

Notes
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RFC 3261 says:

Section 12.1: "Dialogs are created through the generation of non-failure responses to requests with specific methods.  Within this specification, only 2xx and 101-199 responses with a To tag, where the request was INVITE, will establish a dialog."

Section 12.1.1: "When a UAS responds to a request with a response that establishes a dialog (such as a 2xx to INVITE), the UAS MUST copy all Record-Route header field values from the request into the response [...].  The UAS MUST add a Contact header field to the response."

So it's clear that a 1xx response to an INVITE creates a dialog and then it MUST contain a Contact header and mirrored Record-Route headers.

However Table 2 (page 162) says:

      Header field          where   proxy ACK BYE CAN INV OPT REG
      ___________________________________________________________
      Contact                1xx           -   -   -   o   -   -
      Record-Route        2xx,18x    mr    -   o   o   o   o   -

Obviously Record-Route is optional since in the absence of a proxy doing record-routing, such header will not be present. However Contact header should appear as mandatory (m) for 1xx responses for INVITE rather than optional (o).

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RFC3261 (draft-ietf-sip-rfc2543bis-09)
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Title               : SIP: Session Initiation Protocol
Publication Date    : June 2002
Author(s)           : J. Rosenberg, H. Schulzrinne, G. Camarillo, A. Johnston, J. Peterson, R. Sparks, M. Handley, E. Schooler
Category            : PROPOSED STANDARD
Source              : Session Initiation Protocol
Area                : Real-time Applications and Infrastructure
Stream              : IETF
Verifying Party     : IESG