Subject: Protocol Action: MIME media types for ISUP and QSIG Objects to Proposed Standard

From: The IESG <[email-masked]>
Date: Wed, 23 May 2001 16:10:32 -0400

The IESG has approved the Internet-Draft 'MIME media types for ISUP and
QSIG Objects' <draft-ietf-sip-isup-mime-10.txt> as a Proposed
Standard.  This document is the product of the Session Initiation
Protocol Working Group.  The IESG contact persons are Allison Mankin
and Scott Bradner.

Technical Summary
 
   This draft defines MIME types for application/ISUP and
   application/QSIG objects for use in SIP applications, according to
   the rules defined in RFC 2048.  These types can be used to
   identify ISUP and QSIG objects within a SIP message such as INVITE or
   INFO, as might be implemented when using SIP in an environment where
   part of the call involves interworking to the PSTN.

   ISUP (ISDN User part) defined in the ITU-T recommendations Q.761-4 is
   a signaling protocol used between telephony switches.  There are
   configurations in which ISUP-encoded signaling information needs to
   be transported between SIP entities as part of the payload of SIP
   [RFC2543] messages, where those messages must also affect logic of
   intervening PSTN systems.

   QSIG is the analogous signaling protocol used between private branch
   exchanges to support calls within private telephony networks.  There
   is a similar need to transport QSIG-encoded signaling information
   between SIP entities in some environments.

   The draft is specific to this usage and would not
   apply to the transportation of ISUP or QSIG messages in other
   applications. These media types are intended for ISUP or QSIG
   application information that is used within the context of a SIP
   session, and not as general purpose transport of SCN signaling.

   The definition of media types for ISUP and QSIG application
   information does not address fully how the non-SIP and SIP entities
   exchanging messages determine or negotiate compatibility.  It is assumed
   that this is addressed by alternative means such as configuration of
   the interworking functions.  The specification primarily defines the
   and registers the mime media types.

   Information contained in ISUP and QSIG bodies may include sensitive
   customer information, potentially requiring use of encryption.
   Payload encryption mechanisms are provided in RFC 2543 and should be
   used as appropriate for both the SIP message and the encapsulated
   ISUP and QSIG body.

Working Group Summary

  The working group achieved consensus to advance the draft.

Protocol Quality

  The draft was reviewed for the IESG by Allison Mankin.