Basic Level of Interoperability for SIP Services

Document Charter Basic Level of Interoperability for SIP Services WG (bliss)
Title Basic Level of Interoperability for SIP Services
Last updated 2007-06-07
State Approved
WG State Concluded
IESG Responsible AD Robert Sparks
Charter Edit AD (None)
Send notices to (None)


The BLISS working group is rechartered to adjust
  its scope to reflect changes in working group interest
  and RAI processes since its original chartering.
  BLISS was chartered prior to the creation of DISPATCH.
  The charter called for the WG to document how to realize
  four initial building blocks in an interoperable way with
  existing standards, and to describe the use of those building
  blocks to implement specific call features. Any extensions
  to the protocols beyond the creation of event packages or
  the addition of SIP URI parameters was set out of scope
  for this working group.
  Working group interest in all but two of those building
  blocks has diminished.  The current drafts on those two
  propose extensions that under the original charter would
  need to be developed in other working groups. Given the
  update to the SIP change process (RFC5727) and the
  subsequent restructuring of the RAI area, these constraints
  are being revised as detailed below.
  The BLISS working group shall be closed after completing
  the following two proposed standards:
   - call completion with queuing as proposed in
   - shared appearances as proposed in
  The goal to produce a problem statement and a
  common template for describing primitives is abandoned.
  The group will continue to work within the constraints of
  the creation of event packages and SIP URI parameters, with
  the addition of the ability to
   - exercise the already standardized extension points of
     SIP header fields. Currently, the documents propose to
     extend the SIP Alert-Info header field (RFC3261) to carry
     an appearance identifier, and the SIP Call-Info header
     field (RFC3261) to carry a call completion indicator.
   - extend the SIP Dialog event package (RFC4235) to carry
     appearance related state,
  The working group will coordinate review of those extensions
  with the SIPCORE working group.
  Describing the security properties (particularly any privacy
  considerations) of these deliverables remains of special
  Upon completion of these two work items, the working group
  will conclude. Future proposals should be directed to the
  DISPATCH working group.