CURRENT_MEETING_REPORT_


Reported by Tony Ballardie/UCL

Minutes of the Inter-Domain Multicast Routing BOF (IDMR)

The IDMR BOF was chaired by Tony Ballardie.  The Minutes were taken by
Benny Rodrig.  The CBT Protocol was discussed for the duration of the
session, in particular, the changes in the protocol since last
November's IDMR BOF session.

Multicast Scope Control

One possible solution to multicast scope control was presented based on
having a separate group per level of scope required.  This resulted in a
considerable debate as to how multicast scoping should be defined and
the requirements of users it should be able to satisfy.  The solution
presented was deemed unsuitable, and it was agreed to continue the the
discussion on the IDMR mailing list.  The conclusion was that the Group
should work towards a concise definition of multicast scope control.

Part of the group initiation procedure includes the group initiator
(host) updating DNS (via a system administrator) with the relevant group
information.  The concern was raised that the procedure is likely to be
too slow.  This part of group initiation may need to be revised to keep
group join latency to a minimum.

Multicast Data Packets

There was a brief discussion on the issue of multicast data packets
carrying the group-id as an IP option.  The conclusion however, was that
there was no more suitable alternative.

When a parent/parent link fails, it was decided that both the flush-tree
and re-join mechanisms should be implemented.  Which of the two
mechanisms eventually becomes redundant can only be decided after a
period of performance testing.

It was decided that non-primary cores should be less stringent in
accepting join-requests.  Also, an additional error detection mechanism
is required by routers to distinguish on-tree packets arriving via a
child as link-level unicast.

The Draft includes no mention of child-parent ``keepalives'' and no
mention of a handshake protocol between a group initiator and potential
cores for that group.  The Draft needs updating in these respects.

The control packet format should contain a group-id TYPE as an
additional protocol independence feature.

Finally, Paul Francis gave a brief description of how CBT will run over
PIP.

Attendees

Anthony Ballardie        A.Ballardie@cs.ucl.ac.uk
Jim Beers                Jim.Beers@cornell.edu
Robert Braden            braden@isi.edu
Scott Brim               Scott_Brim@cornell.edu
David Carr               Carr@acsu.buffalo.edu
Stephen Casner           casner@isi.edu
Steve Deering            deering@parc.xerox.com
Steve DeJarnett          steve@ibmpa.awdpa.ibm.com
Ed Ellesson              ellesson@vnet.ibm.com
Chip Elliott             celliot@bbn.com
Dino Farinacci           dino@cisco.com
Paul Francis             Francis@thumper.bellcore.com
Chris Gunner             gunner@dsmail.enet.dec.com
Joel Halpern             jmh@network.com
Ken Hayward              Ken.Hayward@bnr.ca
Robert Hinden            hinden@eng.sun.com
Frank Hoffmann           hoffmann@dhdibm1.bitnet
Gerd Holzhauer           holzhauer1@applelink.apple.com
Tony Li                  tli@cisco.com
Charles Lynn             clynn@bbn.com
Kent Malave              kent@bach.austin.ibm.com
Jun Matsukata            jm@eng.isas.ac.jp
David Meyer              meyer@ns.uoregon.edu
Gerry Meyer              gerry@spider.co.uk
Greg Minshall            minshall@wc.novell.com
Matthew Morrisey         morrisey@wpsp01.hq.aflc.af.mil
William Owens            owens@acsu.buffalo.edu
Laura Pate               pate@gateway.mitre.org
Geir Pedersen            Geir.Pedersen@usit.uio.no
Willi Porten             porten@gmd.de
Benny Rodrig             4373580@mcimail.com
Sally Tarquinio          sallyt@gateway.mitre.org
Fumio Teraoka            tera@csl.sony.co.jp
Paul Traina              pst@cisco.com