CURRENT_MEETING_REPORT_


Reported by Rob Coltun/Consultant

Minutes of the Virtual Circuit Routing BOF (VCROUT)

The Group's first session began with a discussion of the VC Routing
Architecture Draft and ended somewhere on planet ATM-Forum-Flashback.
Several interesting issues were raised here.

Radia Perlman suggested that the routing protocol should be scalable to
any level of hierarchy so that a prefix address advertised by a switch
may represent directly connected terminals or an aggregation address of
a directly connected sub-network.

Juha Heinanen was concerned that a 32 bit address is not sufficient.  It
is big enough to identify the exchange portion of a North American
Numbering Plan address, should be big enough for the routable portion of
other E.164 addresses, and is big enough for the routable part of a
GOSIP-style NSAP (Rd/Area).  However, it was pointed out that the
GOSIP-style NSAP format may be used in a more efficient manner than
suggested in RFC1237 (i.e., the Rsvd field may have significance and the
RD/Area separation may not be clear cut).  This makes a 32 bit address
useless.

Dan had a strong objection to using the transit carrier ID for call
setup in VC networks.

Fore's SPANS

Next, Drew from Fore systems presented an overview of Fore's SPANS
(Simple Protocol for ATM Network Signaling) protocol.  The presentation
included Fore's internal addressing, UNI, NNI, QoS, SPF routing
algorithm, multicast solution and connectionless server.

Goals of Proposed Working Group

The second session started with a discussion of the goals and milestones
of the proposed VCROUT Working Group.  The following goals were agreed
to:


  o The Working Group will initially focus on protocols for use within
    a single VC network (intra-domain routing).  Routing for a VC
    internet (inter-domain routing) is also within the Charter.

  o Initial specifications to focus on what each switch needs to
    monitor to describe its local topology (including neighbor
    interactions), and the protocol for distributing/updating topology
    information should be in Internet-Draft form by the end of June and
    submitted as a Proposed Standard by the end of '93.

                                  1





  o Interaction between the the CAC and the routing information should
    be worked out, such that by June, a description of how it would
    work, with a list of requirements needed from the UNI signaling and
    NNI signaling detailed for liaison with the ATM Forum.  Any
    modifications should have worked out trade-offs described.

  o As part of the interaction between the the CAC and routing, ways of
    describing the performance expected by a switch rather than the
    algorithm used by the switch should be explored.


VC-Routing Proposal

We then had a brief overview of the vc-routing proposal, focusing on
routing metrics and how they may be used by signaling.

Marek suggested that for high-speed networking, the minimum propagation
delay between switches is related to the geographic distance between the
switches.

Tony questioned the stability of a system that would be doing call
set-up based on metrics that are in part reflecting available resources.

Allison gave a presentation on congestion control implications in
signaling which began with the question ``Do we really gain if routing
protocol ``helps'' call admission control?''  and continued with an
overview of a number of (as of yet unresolved) signaling issues
regarding the terminal (hosts and routers) to switch interaction.  This
presentation (vcroute_mankin.txt) is available on the machine
gated.cornell.edu in the pub/ospf directory.

Distant-Vector Protocol

There was a short discussion on the possible use of a distant-vector
protocol to be used for a VC routing protocol.  Yakov brought up the
point that there is usually no policy routing within the IGP and that
congestion avoidance and QoS requirements can be met on a hop-by-hop
basis.  Others countered that keeping the map at the source (i.e., using
a link-state routing protocol) and doing a source route call setup was a
superior technical approach.

Tony suggested that a VC domain should be able to inform IDRP of
reachability information.

The Group agreed to meet at the Amsterdam IETF.

Attendees

David Arneson            [email protected]
Fred Baker               [email protected]
Jim Beers                [email protected]
Nutan Behki              [email protected]

                                  2





Lou Berger               [email protected]
Caralyn Brown            [email protected]
Jeff Carman              [email protected]
George Clapp             [email protected]
Robert Cole              [email protected]
Rob Coltun               [email protected]
Dave Cullerot            [email protected]
Steve DeJarnett          [email protected]
Osmund DeSouza           [email protected]
Chas DiFatta             [email protected]
M.J. Dixon               [email protected]
Kurt Dobbins             [email protected]
Bob Downs                [email protected]
Chip Elliott             [email protected]
Robert Enger             [email protected]
Michael Fidler           [email protected]
Karen Frisa              [email protected]
Mike Goguen              [email protected]
Kenneth Goodwin          [email protected]
Daniel Grossman          [email protected]
Chris Gunner             [email protected]
Joel Halpern             [email protected]
Patrick Hanel            [email protected]
Ken Hayward              [email protected]
Juha Heinanen            [email protected]
Frank Hoffmann           [email protected]
Kathy Huber              [email protected]
Fong-Ching Liaw          [email protected]
Andrew Malis             [email protected]
Tracy Mallory            [email protected]
Allison Mankin           [email protected]
Keith McCloghrie         [email protected]
Gerry Meyer              [email protected]
David O'Leary            [email protected]
Zbigniew Opalka          [email protected]
Ayal Opher               [email protected]
John Penners             [email protected]
Maryann Perez            [email protected]
Drew Perkins             [email protected]
Radia Perlman            [email protected]
Hal Sandick              [email protected]
Shiva Sawant             [email protected]
Andrew Schmidt           [email protected]
Kanan Shah               [email protected]
Andrew Smith             [email protected]
Marco Sosa               [email protected]
Subbu Subramaniam        [email protected]
Terry Sullivan           [email protected]
Sally Tarquinio          [email protected]
Marek Tomaszewski        [email protected]
Scott Wasson             [email protected]
James Watt               [email protected]
Rick Wilder              [email protected]
Steven Willis            [email protected]

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