CURRENT_MEETING_REPORT

CURRENT_MEETING_REPORT_

Reported by Mark Laubach/Hewlett-Packard

Minutes of the IP Over Asynchronous Transfer Mode Working Group (ATM)

Monday

The first session opened with a formal announcement by Robert Hinden
that he has stepped down as the ATM Working Group chair and that Mark
Laubach has assumed the responsibility.

The agenda was presented and approved.

A review of recent ATM Forum activities was presented by Steve Willis.
He reported that the User Network Interface (UNI) Specification Version
3.0 document is expected to be ratified in August.

An overview of the European ATM pilot project was presented by Juha
Heinanen.

The topic of ``routing IP over the switched virtual cloud'' was
presented by Joel Halpern, and he volunteered to write a proposal.
Consensus is that the ATM Working Group will host the proposal, but
actual work will be moved to another group that deals with routing over
large public networks.

A general discussion was held to collect comments on Randall Atkinson's
Internet-Draft, ``Default IP MTU for use over ATM AAL5 Services.'' The
author was not in attendance.

The last order of business was discussion of Mark Laubach's ``Classical
IP and ARP over ATM'' Internet-Draft (henceforth called ``Classical'').
Discussion and consensus building continued over the next two meetings.

Tuesday

The second session opened with discussion of a timetable of ATM
activities for the rest of 1993.

Both the Bellcore and Naval Research Laboratory (NRL) reference
signaling codes will become available in late August or early September.
Both implementations will be ATM Forum UNI 3.0 compliant, with the
exception of point-to-multipoint.

An IP over UNI 3.0 document is expected to be completed and have
implementation experience by the November IETF meeting.

The rest of the session was spent on discussion of Classical. During
the discussion, the Internet Area Director, Stev Knowles, made it
perfectly clear that Classical was not complete until ARP and IP
multicast were fully addressed. (The position that area directors may
delay an Internet-Draft from being submitted into the standards process
was supported by the IAB in an open meeting later that evening.)
Document review continued with a renewed sense of focus. LLC/SNAP was
adopted by consensus as the default (the minimum required that
implementors must support) IP encapsulation method. The IP MTU default
size of 9180 octets was also adopted by consensus.

Wednesday

The last session opened with congratulations to Juha Heinanen for the
publication of RFC 1483, ``Multiprotocol Encapsulation over ATM
Adaptation Layer 5.''

Work then continued on Classical with the discussion of PVC support. A
section on PVC support was generated for the document by an ad hoc team,
and the text was approved by the group. An edited version of the text
will be included in the document.

Further discussion on Classical took place following a presentation by
Mark Laubach on a solution for ARP using an APR server. The group
eventually reached consensus on the solution. Mark also presented
solutions for the treatment of IP broadcast and IP multicast in ATM.
These were also approved.

Having reached consensus on all issues, discussion on Classical was
closed. Mark will produce a rewrite within the next two weeks.

Juha Heinanen led a discussion on his ``NBMA Address Resolution Protocol
(NBMA ARP)'' Internet-Draft. Much discussion was generated on this
topic, but unfortunately not enough time was available to conclude all
issues. Juha will meet with others in the working group to resolve
outstanding issues.

The following are detailed summaries of the various discussions including
consensus decisions by the working group.

--------------------------------------------------------------------------
ATM FORUM Update, Steve Willis, Mike Goguen, Andrew Malis, Joel
Halpern, Drew Perkins, Mark Laubach, et al.

o Signaling was closed at next meeting of the Forum in June.
Touch up of point to multipoint addressing will be done in July.
The ATM-FORUM will take a vote in August to adopt Uni 3.0 as an
Implementation Reference.

o Physical, agenda for settling issues. Time schedule:
- 7/93, pick a bit rate for UTP3 (25 vs 51Mbps)
- 9/93, pick a line encoding

o Private NNI working group is starting in July. VC routing to be
worked on in the ATM-FORUM. Mike Goguen (and probably Joel Halpern)
will keep IETF experts involved where possible. Joel will likely
create an information sharing activity between the ATM-FORUM working
group and the IP routing over large public data networks activity
(see below for more information on IP routing issues).

o LAN Emulation, starts next meeting. Keeping Novell, bridging, et al.
working. May be host services emulation. We've heard a rumor that
they may be looking at encapsulation issues. Also, the FORUM Working
Group has not decided their plans in detail.

o ATM FORUM intends to support the output of the RFCs from this
working group unchanged.

o The Issue of getting ATM FORUM documents was raised. The Interop
ATM-FORUM address was distributed and we've told folks that the
Uni 3.0 spec should be available for $25.00 sometime in/after
August. Mark Laubach also committed to seeing if we can find an
electronic mechanism for distributing on the Internet.

o Mark Laubach will contact Glenn Estes (Bellcore) regarding strengthing
the information flow between the technical committee of the ATM-FORUM
and this working group. Our working group time frame indicates that the
November IETF meeting will likely discuss IP over UNI 3.0 standardization
and any implementation experience we've gained at that point. An invite
will be put to the ATM-FORUM to see if any signaling technical people
can come to the working group meetings at the November IETF. A challenge
will be put to the ATM-FORUM to allow IETF working group attendees to go
to ATM-FORUM meetings, we believe that the FORUM's rules will not allow
this. The best we can probably hope for is to have IETF working group
attendees who are ATM-FORUM members to support information exchange.

------------------------------------------------------------------------
EUROPEAN ATM PILOT, Juha Heinanen

Juha presented a quick look at an ATM project in Europe:

o ATM is quite a big thing in Europe, bigger than SMDS or Frame relay

o At least 34 Mbps pilot network

o 17 network operators have sign a memorandum of understanding

o Access speeds not defined in this pilot, operators can use whatever
speed to get to the customers

o Only the NNI is specified for PVC (virtual path)
Conforming with some European standards, small subnet of CCITT spec,
Ok with ATM-FORUM UNI 2.0 specification.

o No more than three hops (operators) between end points.

o Goal is for operators to gain experience and test the standards
The real issue is that the operators want to get into the ATM bandwagon

o EC competition rules would make this network illegal for the long
term operation

o Nordic area is aiming at 155 Mbps trunks

------------------------------------------------------------------------
IP ROUTING over the Switched Virtual Cloud, Joel Halpern

Joel led a discussion of IP routing over large switched public data
networks. He is preparing a proposal. As this is an IP routing issue
and not an IP-over-ATM issue, further work on this will not take place
in this working group. Whatever activities will take place a future
IETF meetings will stay closely linked to the ATM Working Group.

Points from Joel's talk:

o It is not ARPs problem to figure out who you really should talk to.
This applies not just to ATM, but to frame relay, and x.25

o BGP next hop is very handy

o Picking up where directed ARP and short-cut routing left off.

o This should be a generally applicable solution that darn well ought
to work on ATM.

o Can point-to-multipoint change the solution space? Joel thinks not
as things should be point-to-point based.

o Clearly you don't want the routing data to be non-aggregated

o This came up with IDRP, can build stub-routing entities

o Without a way to route over the cloud.

o Juha: some sort of route query protocol where a terminal attached to
an ATM network and set up a route request query to a server and get a
response back.

o This is not completely new work. Some ability to query and store
information. Can invent a new protocol.

o We want to have it before the large ATM cloud comes into existence.

o We don't want to wait until IPng.

o This effort will tie to the routing protocols.

o Joel will create a proposal and will distribute on the mailing list
A nub of a design. He will try to get a proposal out to the e-mail
list in the very near future.

------------------------------------------------------------------------
MTU Draft Comments

These are merely comments collected at the working group meeting as we
had a large collection of people there. These comments do not
represent any formal opinion of the group.

o Drew Perkins: ATM FORUM terminology has changed
AAL5 PDU size is 64K-1. Minimum size should be deleted from the
document IP has a minimum reassembly size is 576 bytes. This is
not the real minimum size. Bob: our documents should have rough
description of how to reduce the MTU size.....

o Juha: too much implicit stuff going on in document.
We clearly need to use exactly the same mechanism is specified in
the FORUM.

------------------------------------------------------------------------
Working Group Schedule

The following time schedule for our working group activities was
discussed.

1993 1994
ITEM M J J A S O N D | J F M A M
---------------- ----------------------------------------
Encapsulation x

Classic Document x..x

The "next" document x.....?

ATM Forum UNI 3.0 x..x

NRL Signaling x..x
Release

Bellcore Signaling x..x
Release

Framework

WORKING GROUP TODOs:
---------------------
1. IP encapsulation negotiation via UNI 3.0 signaling
2. MTU size negotiation via UNI 3.0 signaling (Ran's document)
3. TCP/UDP Port mapping directly on to VCs, architecture impact
4. Routing over the Switched Cloud
5. Multicasting
6. NBMA

The hopes are that with the release of the NRL and Bellcore signaling
stacks, the working group should be able to review implementation
experience at the next meeting in Houston. The "next" document, i.e.
IP over UNI 3.0, should be reviewable by the next meeting. No one
volunteered to write this yet.....

------------------------------------------------------------------------
Classical IP and ARP over ATM draft discussion items and decisions. All
decisions were reached with clear consensus by the working group:

o PVC support in the classical document was an issue. A section was
generated by an ad hoc team during the Wednesday lunch break. The
working group approved the text. An edited version of the text will
be included in the classical draft.

o Last part of paragraph on ANSI ITU-TSS....stricken (from introduction)

o Working group approved by the default (required) implementation of 9180
bytes MTU size. Text regarding minimum size was stricken.

o Working group approved that LLC/SNAP be the default (required)
encapsulation for IP packets: i.e., all implementations MUST be able to
support LLC/SNAP as one of the encapsulation choices.

o Working group approved by the ARP server architecture model as proposed
by Mark Laubach. We had some lengthy discussion on the issue of providing
primary and backup servers and the working group clearly decided that a
single ARP server will be required per logical IP subnet and that this
would be sufficient for the near future (year) until ATM multicast or
highly reliable ARP servers are implemented. The proposed model will roll
to either future implementation without changes to the host. The issue
was raised of soliciting the ATM-FORUM for the allocation of a well-known
ATM address for ARP.

o Working group concluded that current ATM standards and technology do not
provide any broadcast mechanisms and as such the classical draft will not
specify an IP broadcast to ATM broadcast mechanism. Hosts may transmit
packets that select the IP broadcast (all ones) or subnet broadcast (all
ones in host portion). Hosts, upon receiving an IP broadcast or IP
subnet broadcast for their logical IP subnetwork, must process the
packet as if addressed to them directly.

o Working group concluded that current ATM standards and technology do not
provide any multicast mechanisms and as such, the classical draft will not
specify an IP multicast to ATM multicast mapping. The working group agreed
that current IP multicast implementations (i.e., MBONE and IP tunneling)
will continue to operate over ATM based logical IP subnets if operated
in the WAN configuration. Furthermore, the working group would like to
have a statement added to the IP multicast section stating something to
the effect that, when ATM multicast is available, roll-over from to the
new architectures will be straightforward.

Mark will prepare the new version of the draft and distribute it within
two weeks. As we are trying to fast track this document, technical review
and final consensus on the draft will be collected via e-mail.

NBMA draft review. Juha Heinanen

Unfortunately, discussion of the classical draft and related issues took
up most of the time of the working group. We managed to close and give
20 minutes on the last day to Juha to lead the discussion of his NBMA
draft. Clearly this was not enough time as much discussion was generated.
I was able to record the following comments during the discussion:

o Just use source routing (Brian Carpenter),

o Dennis Ferguson has issues about this should really be a routing issue
and not an ARP issue and that we really should have a routing protocol
that does all (in the IP layer).

o Joel Halpern stated that he is thinking about this in his routing
protocol proposal. Are all NBMA servers IP routers? Joel feels that
we need to be able to follow the NBMA model and resolve via ARP.

o Dennis would really like this issue to be solved with an IP level
protocol. SMDS has a different ARP mechanism than ATM, but this NBMA
issue is the same. Dennis would like to have a media independent
solution. Dennis wants a cleaner separation.

o Mark Laubach would like a clean description of the changes to the
routing decision process / architecture on a host (when it makes
decisions and what gets relaxed).

o Juha is getting together with Joel to work on the issues.

Attendees

George Abe [email protected]
Roland Acra [email protected]
Masuma Ahmed [email protected]
Kannan Alagappan [email protected]
Arun Arunkumar [email protected]
Cynthia Bagwell [email protected]
Nutan Behki [email protected]
Lou Berger [email protected]
Vincent Berkhout [email protected]
Carsten Bormann [email protected]
Michael Brescia
Caralyn Brown [email protected]
Tracy Brown [email protected]
Theodore Brunner [email protected]
Steve Buchko [email protected]
John Burnett [email protected]
Ramon Caceres [email protected]
Brian Carpenter [email protected]
Les Clyne [email protected]
Jonathan Davar [email protected]
Kurt Dobbins [email protected]
Jeffrey Dunn [email protected]
Tom Easterday [email protected]
Ed Ellesson [email protected]
Robert Enger [email protected]
Julio Escobar [email protected]
Mark Fedor [email protected]
Dennis Ferguson [email protected]
James Forster [email protected]
Osten Franberg [email protected]
David Fresquez [email protected]
Dan Frommer [email protected]
Shoji Fukutomi [email protected]
Eugene Geer [email protected]
David Ginsburg [email protected]
Mike Goguen [email protected]
Ramesh Govindan [email protected]
Marcel Graf graf%[email protected]
Ron Greve [email protected]
Joel Halpern [email protected]
Patrick Hanel [email protected]
Ken Hayward [email protected]
Geert Heijenk [email protected]
Juha Heinanen [email protected]
John Hopkins [email protected]
Jeff Hughes [email protected]
Sascha Ignjatovic [email protected]
Phil Irey [email protected]
Ronald Jacoby [email protected]
David Johnson [email protected]
John Johnston [email protected]
Peter Kaufmann [email protected]
Lothar Klein [email protected]
Mark Laubach [email protected]
Mark Lewis [email protected]
Carl Madison [email protected]
Andrew Malis [email protected]
Allison Mankin [email protected]
Jun Matsukata [email protected]
Keith McCloghrie [email protected]

3

Donald Merritt [email protected]
Topi Miettinen [email protected]
William Miskovetz [email protected]
Daniel Myers [email protected]
David O'Leary [email protected]
Masataka Ohta [email protected]
Zbigniew Opalka [email protected]
Charles Perkins [email protected]
Drew Perkins [email protected]
Roy Perry [email protected]
Philip Prindeville [email protected]
J. Mark Pullen [email protected]
James Reeves [email protected]
Tony Richards [email protected]
Benny Rodrig [email protected]
Hal Sandick [email protected]
Tim Seaver [email protected]
Henk Sennema [email protected]
W. David Sincoskie [email protected]
Timon Sloane [email protected]
Kenneth Smith [email protected]
Michael St. Johns [email protected]
Antoine Trannoy [email protected]
Catherine Treca [email protected]
Hisao Uose [email protected]
Dono van-Mierop [email protected]
Werner Vogels [email protected]
Scott Wasson [email protected]
James Watt [email protected]
Jost Weinmiller [email protected]
Marcel Wiget [email protected]
Kirk Williams [email protected]
Steven Willis [email protected]
Rachel Willmer [email protected]
Sam Wilson [email protected]
Paul Zawada [email protected]