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-
-
- CURRENT_MEETING_REPORT_
-
-
- Reported by George Clapp/Ameritech
-
- IPLPDN Minutes
-
- Opening Remarks
-
- This was the second meeting of the IP over Large Public Data Networks
- Working Group and the following was the Agenda of the meeting:
-
-
- o Wednesday, March 13, 1991
-
- - Tutorial on Frame Relay (FR) by Andy Malis
- - Discussion of encapsulation and protocol multiplexing over FR
- - Tutorial on ISDN (Wayne Heinmiller and Jim Loehndorf)
- - Discussion of encapsulation and protocol multiplexing over ISDN
-
- o Thursday, March 14, 1991
-
- - Joint meeting with the BGP Working Group to discuss the use of
- BGP for routing and address resolution (Paul Tsuchiya)
- - Continued discussion of encapsulation and protocol multiplexing
-
-
- Frame Relay Tutorial
-
- Due to airplane troubles, Andy Malis had been unable to present his
- tutorial on Frame Relay during the plenary the previous evening, so he
- kindly presented his talk during the first half of Wednesday morning's
- Working Group session. (Andy also presented this tutorial during the
- Friday morning plenary, and a copy of his presentation is included in
- the Proceedings for that session. A postscript version is online for
- anonymous ftp at ``pub/ietf-frame-relay-intro.ps'' on ccv1.bbn.com) The
- presentation was an excellent preparation for the discussion of
- encapsulation and protocol multiplexing.
-
- Encapsulation and Protocol Multiplexing for Frame Relay
-
- After the tutorial Caralyn Brown presented the following encapsulation
- and protocol multiplexing scheme for Frame Relay. The proposal is
- documented in the draft ``Multiprotocol Interconnect over Frame Relay
- Networks'', which is available online on ccv1.bbn.com for anonymous ftp
- as ``pub/multiprotocol.txt''. (A copy of the viewgraphs of Caralyn's
- presentation accompanies these minutes.)
-
- 1
-
-
-
-
-
-
- +--------------------+
- | LAPD flag (0x7E) |
- +--------------------+
- | DLCI |
- +--------------------+
- | DLCI... |
- +--------------------+
- | Format Identifier |
- +--------------------+
- |FCSP| Origin_Media |
- +--------------------+
- | ... |
- +--------------------+
- | Info |
- +--------------------+
- | ... |
- +--------------------+
- | Frame Ck Sequence |
- +--------------------+
- | Frame Ck Sequence |
- +--------------------+
- | LAPD flag (0x7E) |
- +--------------------+
-
-
-
- FCSP: Frame Check Sequence Preservation
-
- The Format Identifier indicates whether 802.2 and SNAP or a bridged MAC
- frame follows, and the Origin_Media indicates the type of the bridged
- MAC frame. If a routed packet is being carried, then the Origin_Media
- value is set to zero and the 802.2 LLC Type 1 and SNAP headers follow.
- The Ethertype of the SNAP header is used to indicate the type of the
- routed packet. This proposal was modified by Charles Carvalho, who
- proposed that the 802.2/SNAP headers be eliminated by carrying both the
- bridged MAC frame type and the Ethertype values within a combined Format
- Identifier/Origin_Media field. There was qualified acceptance of this
- approach before the group broke for lunch.
-
- ISDN Tutorial and Proposal
-
- Wayne Heinmiller with Jim Loehndorf presented an overview tutorial on
- ISDN (a copy of the presentation accompanies these minutes). The
- presentation led into a talk by Dory Leifer of proposed encapsulation,
- protocol multiplexing, and fragmentation schemes for circuit and LAPD
- ISDN. The proposal is documented in the draft ``A Subnetwork Control
- Protocol for ISDN Circuit-Switching'', which is available online on
- terminator.cc.umich.edu as `` ftp/isdn'' for anonymous ftp. Further
- discussion was deferred until the next morning.
-
-
-
- 2
-
-
-
-
-
-
- Joint Meeting with BGP Working Group
-
- Paul Tsuchiya led a joint meeting of the IPLPDN and BGP Working Groups.
- (A copy of his slides accompany the minutes.) Paul proposed alternative
- mechanisms to support a simple and effective way for routers to obtain
- routing and address resolution information from BGP servers. He also
- proposed an extension to BGP in which both the next hop IP address and
- the hardware, or SubNetwork Point of Attachment (SNPA), address would be
- given to the requesting router.
-
- Members of the BGP group were concerned with potential conflicts between
- policies of the Autonomous Systems that might be traversed by a packet.
- This discussion remained unresolved and Paul volunteered to work towards
- a solution in time for the next meeting.
-
- Encapsulation and Protocol Multiplexing
-
- After the break, IPLPDN met separately from the BGP Working Group and
- Caralyn Brown presented the modified proposal for encapsulation and
- protocol multiplexing over Frame Relay. (A copy of the viewgraph of the
- proposal accompanies the minutes.)
-
-
- +--------------------+
- | LAPD flag (0x7E) |
- +--------------------+
- | DLCI |
- +--------------------+
- | DLCI... |
- +--------------------+
- | Format ID 1 |
- +--------------------+
- | Format ID 2 |
- +--------------------+
- | ... |
- +--------------------+
- | Info |
- +--------------------+
- | ... |
- +--------------------+
- | Frame Ck Sequence |
- +--------------------+
- | Frame Ck Sequence |
- +--------------------+
- | LAPD flag (0x7E) |
- +--------------------+
-
-
-
- 3
-
-
-
-
-
-
- If the value of the Format Identifier is less than 1024 decimal (0x0400)
- then the field is used to encode the MAC type and the code points are
- identical to those in internet-draft ``Point to Point Protocol
- Extensions for Bridging''. This is shown below.
-
-
- 0 1
- 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
- +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
- | 0 | 0 | 0 | 0 | 0 | 0 | F | Z | MAC TYPE |
- +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
-
-
-
- The F bit is used to indicate the presence of the MAC Frame Check
- Sequence, and the Z bit is used to indicate zero compression.
-
- If the value of the Format Identifier is 1024 decimal (0x0400) then the
- 802.2 LLC header follows the Format Identifier field, as shown below.
-
-
- 0 1
- 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
- +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
- | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
- +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
- | DSAP | SSAP |
- +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
- | Control |
- +---+---+---+---+---+---+---+---+
-
-
-
- If the value of the Format Identifier is greater than 1024 decimal
- (0x0400) then the encoded Format Identifier is equivalent to the
- Digital-Intel-Xerox (DIX) Ethertype, as shown below.
-
-
- 0 1
- 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
- +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
- | Digital-Intel-Xerox (DIX) Ethertype |
- +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+
-
-
-
- Caralyn continued with a discusion of mechanisms for address resolution
- and proposed that ARP be used to discover the DLCI associated with an IP
-
- 4
-
-
-
-
-
-
- address. She also proposed an extension to ARP named Inverse ARP to
- discover the IP address associated with a DLCI. This latter proposal is
- documented in the draft ``Inverse Address Resolution Protocol'', which
- is available online by anonymous ftp on ccv1.bbn.com as
- ``pub/inarp.txt''.
-
- After some discussion and modifications, all of these proposals appeared
- to be acceptable to the group.
-
- IP over ISDN
-
- Dory Leifer continued with a discussion of the following issues:
-
-
- o Fragmentation - do we need it considering the access network may
- impose small max frames?
- Resolution: further study
-
- o End-to-end link state for switched access, i.e., XID frames?
- Resolution: no
-
- o ACK mode support or at least include CONTROL field for Q.921
- compatibility?
- Resolution: the group accepted the CONTROL field with a pad in the
- encapsulation scheme. The revised scheme is shown below.
-
-
- +-----------+
- | flag |
- +-----------+-----------+
- | DLCI | DLCI.. |
- +-----------+-----------+
- | Control | PAD |
- +-----------+-----------+
- | Format ID | Format ID |
- +-----------+-----------+
- | info.. | ... |
- +-----------+-----------+
- | ... | ... |
- +-----------+-----------+
- | CRC | CRC |
- +-----------+-----------+
- | flag |
- +-----------+
-
-
- o Discovery protocol of Max frame size?
- No resolution
-
-
-
- 5
-
-
-
-
-
-
- o Code point for in-connection management protocol?
- No resolution
-
-
- At this point, time ran out and the group adjourned until the next
- meeting in Atlanta, GA, in July 1991.
-
- Attendees
-
- Karl Auerbach karl@eng.sun.com
- William Babson bill%penril@uunet.UU.NET
- Fred Baker fbaker@emerald.acc.com
- Atul Bansal bansal@netrix.nac.dec.com
- Ron Bhanukitsiri rbhank@wsl.dec.com
- Caralyn Brown cbrown@wellfleet.com
- Howard Brown brown@ctron.com
- Theodore Brunner tob@thumper.bellcore.com
- Lida Carrier lida@apple.com
- Eric Carroll eric@utcs.utoronto.ca
- Charles Carvalho charles@sage.acc.com
- Martina Chan mchan@mot.com
- Cho Chang chang_c@apollo.hp.com
- George Clapp clapp@uunet.uu.net
- Graham Cobb cobb@marvin.enet.dec.com
- Richard Colella colella@osi3.ncsl.nist.gov
- Nabil Damouny
- Tom Easterday tom@cic.net
- Gus Elmer arch1!ae@att.com
- Dennis Ferguson dennis@canet.ca
- Peter Ford peter@lanl.gov
- Daniel Friedman danfriedman@bbn.com
- Charles Gallucci
- Dave Geurs dgeurs@mot.com
- Bret Gorsline jinx@engin.umich.edu
- Martin Gray mg@spider.co.uk
- Olafur Gudmundsson ogud@cs.umd.edu
- Frank Heath
- Kathleen Huber khuber@bbn.com
- B.V. Jagadeesh bvj@esd.3com.com
- Dan Jordt danj@nwnet.net
- Ajay Kachrani kachrani@regent.enet.dec.com
- Manu Kaycee kaycee@trlian.enet.dec.com
- Nam Keung
- Peter Kirstein kirstein@cs.ucl.ac.uk
- Mary Louise Laier laierl@applelink.apple.com
- Michelle Landriault crm57a@bnr.ca
- Joseph Lawrence jcl@sabre.bellcore.com
- Dory Leifer Dory.Leifer@terminator.cc.umich.edu
- Richard Libby libby@c10sd6.stpaul.ncr.com
- Mike Little little@ctt.bellcore.com
- Then Liu
-
- 6
-
-
-
-
-
-
- John LoVerso loverso@westford.ccur.com
- Andrew Malis malis@bbn.com
- Glenn McGregor ghm@merit.edu
- Robert Meierhofer bobm@cl0sd6.stpaul.ncr.com
- Linda Melvin infopath@well.sf.ca.us
- Agnes Moran
- Robert Peglar robp@anubis.network.com
- James Philippou japhilippou@eng.xyplex.com
- Rehmi Post rehmi@ftp.com
- Stephanie Price price@cmc.com
- Ron Roberts roberts@jessica.stanford.edu
- Manoel Rodrigues manoel.rodrigues@att.com
- Allyn Romanow allyn@eng.sun.com
- Allan Rubens acr@merit.edu
- Ray Samora rvs@proteon.com
- Paul Selkirk paul@ftp.com
- Marc Sheldon ms@Germany.eu.net
- Daisy Shen daisy@watson.ibm.com
- Stephen Shew sdshew@bnr.ca
- William Townsend townsend@xylogics.com
- Paul Tsuchiya tsuchiya@bellcore.com
- Robert Ullmann ariel@relay.prime.com
- Kannan Varadhan kannan@oar.net
- Francis Waldman
- Wing Fai Wong wfwong@malta.sbi.com
- Chin Yuan cxyuan@pacbell.com
-
-
-
- 7
-