Subject: [BLISS] Minutes from Call-Completion meeting: 08 02.08

From: Shida Schubert <[email-masked]>
Date: Tue, 12 Feb 2008 14:08:11 -0800

Below is the minutes from the teleconference we
had for Call-Completion design team last week.

Date/Time:
--------------------
2008.02.08 9:00PST-10:00PST

Attendees:
--------------------
- Dale Worley
- Dennis Alexeitsev
- Dennis Lubber
- Enrico Marocco
- Eric Sasaki
- John Elwell
- Martin Huelsemann
- Shida Schubert

Agenda:
----------------------------------
1. Revisit the remaining issues.
 >> Call Retention
 >> Cookie
2. Way forward

Discussion:
-----------------------------------
- Dale explained the use of 130 or 199 (HERFP response) with
  the inclusion of sipfrag containing 486/408 to deal with
  forking situation. In forking situation, 486/408 with the
  call-completion indication may not get through to the UAC,
  therefore by using provisional response that can carry a
  sipfrag of either 486 or 408, this will enable the UAC to
  receive information on  (486 or 408)
  >> As not all understood what's proposed, Dale will post
     a text explaining the details and possibly a call-flow.
  >> There were questions in regards to an environment where
     forking is not going to happen. Dale suggested it's still
     better to send 130 + sipfrag.

- Dale explained the new proposed CC header which contains
  URI of the callee monitor. It enables callee monitor to hold
  a completely different URI from that of a callee. It's useful
  when interworking with PSTN as there may be multiple GWs that
  are involved.
  >> Is it replacing the cookie suggested in the call-info?
   >> No.
  >> Dennis found call-info to be a very suitable vehicle to
     carry an indication of whether it's CCBS or CCNR.

- Dale explained the problem when call-id blocking is enabled in
  PSTN while interworking. In SIP token which may be returned by
  the callee/callee monitor in call-info header that would correlate
  the call that failed and the call-completion activation request,
  but in PSTN because several different GWs may be involved, this
  may not work.
  It was recently suggested to use callee/caller id pair as a key
  to correlate the failed call and the call-completion activation request
  but this doesn't work when call-id blokcing is enabled.
  >> Problem was understood among the participants.
  >> Dale will submit a text and solution that will solve this problem.

- Dale asked if there was a consensus on call-completion being a
  single type of event with different mode. This will enable a future
  innovation by defining new modes.
  >> Design team agreed.

- Some debate on call-retention/resume etc.

- Chair explained that new status code and new header need to be
  defined in SIP WG and co-ordination with SIP is necessary.

- Way Forward
 >> Dale will send a text explaining how 130 will replace the 486/408,
    when it is going to be used and its benefit.
 >> Dennis.A will send a text on the use of call-info.
 >> Dale will send a text on the solution to the privacy issues in
     PSTN interworking.
 >> Dennis.A/Martin will send a text on the use of SUB-pause for
     call retention, resume.

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