CURRENT_MEETING_REPORT_ Reported by Dave Katz/cisco Systems Minutes of the IS-IS for IP Internets Working Group (ISIS) CLNP Multicast Radia Perlman gave a presentation on several methods of achieving CLNP multicast functionality without significantly changing unicast routing. One use of multicast is for service location. This could be achieved in CLNP by using a well-known system ID for each service and advertising it via unicast routing (from multiple locations). This is also known as ``anycast.'' In the very branchy case, one could use NSAP addresses with the multicast bit set in the system ID. Then a single spanning tree per area could be created for all multicast destinations and data packets could be delivered to all subnetworks in the area along this spanning tree. Since it is very branchy, no pruning mechanisms are necessary (making it simple). Inter-area forwarding could be accomplished by simply sending one packet per destination area (normal unicast routing would take place until the packet arrives in its destination area), or by creating a special area address that means ``all areas,'' calculating a single spanning tree over all areas, and delivering the packet to the entire domain. For very sparse multicast with a limited number of participants per group, a scheme such as CBT would be appropriate. One suggested optimization was to tunnel data packets between the routers at the branching points; this eliminates the need to set up state through the non-branching routers. IS-IS Over Non-Broadcast Multiaccess (NBMA) Networks An Internet-Draft has been published on IS-IS over non-broadcast multiaccess (NBMA) networks; the Routing Over Large Clouds Working Group (ROLC) was due to take up the subject during this IETF meeting. The Integrated IS-IS Specification The latest version of the Integrated IS-IS specification Internet-Draft (the changes to which were essentially reference updates) has expired. The protocol cannot continue along the standards track until RFCs describing operational experience and an analysis of the protocol are published. Chris Gunner is working on those documents. Integrated IS-IS for IPX and Appletalk The ISIS Working Group charter needs to be revisited in order that it be broadened to include other topics, such as Integrated IS-IS for IPX and Appletalk. Radia gave a presentation on Integrated IS-IS for IPX and Appletalk. The significant issues include encapsulation (in order to carry data packets through islands that do not provide native forwarding service for the protocol), metric translation, route propagation between areas (and between protocols), clustering issues for protocols with small address spaces (such as the creation of addressing domains for Appletalk), the use of tunnels to carry routing information between areas when the level 2 subdomain does not understand the protocol, and various issues specific to the protocols (zones, services, etc.). An Internet-Draft has been published on the subject. Radia described the new Novell link state protocol for routing IPX, Netware Link Services Protocol (NLSP). NLSP is basically equivalent to IS-IS, and uses compatible packet formats. There are several minor improvements, most of which could be realized in IS-IS without actually changing the protocol definition. There are also several changes deemed necessary for using the protocol in an IPX environment such as the inclusion of service advertisements, and running the protocol over IPX rather than over the data link (though it was observed by some present that this is unnecessary). Several people expressed the view that it would be possible to implement IS-IS and NLSP from a single code base without too much difficulty. IS-IS Enhancements Discussion turned to enhancements and changes that the group might like to pursue with IS-IS. o Increasing the LSP number space to four octets (allowing vast amounts of information to be carried, such as large numbers of BGP routes, and also allowing implementations to use OSPF-style numbering of individual adjacencies) o Designated router ``tenure'' (increasing the DR election priority after being elected DR in order to provide stability for the choice of DR--no protocol change necessary) o Allow different LSP holding time values per LSP (so that static information such as service advertisements can be advertised less often) o Possible fixes to the ``hedgehog'' problem (extremely branchy, low-speed networks). Ross Callon will write this up o Expand the pseudonode ID to two octets (in order to support more than 255 circuits per router) o Multilevel (>2) routers o Multiarea routers (no protocol change necessary) o Integrated IPX/Appletalkrouting o NBMA support o Further definition of the External Info attribute o Multicast routing o Increase the size of link metrics from 6 to 16 bits, and total path cost from 12 to 32 bits Dave Katz agreed to write up a draft for increasing the LSP number, pseudonode ID, and link metric fields, as well as a proposal for how to transition to new versions of the various packets (necessary because the changes are incompatible with the existing packet formats). Attendees Kenneth Albanese albanese@icp.net William Barns barns@gateway.mitre.org Ross Callon rcallon@wellfleet.com Chris Gunner gunner@dsmail.lkg.dec.com Herluf Hansen hha@tbit.dk Susan Hares skh@merit.edu Marc Hasson marc@mentat.com Denise Heagerty denise@dxcoms.cern.ch Cornelius Healy con@icp.net Robert Hinden hinden@eng.sun.com Phil Irey pirey@relay.nswc.navy.mil Matthew Jonson jonson@ddn.af.mil Akira Kato kato@wide.ad.jp Dave Katz dkatz@cisco.com Tony Li tli@cisco.com David Marlow dmarlow@relay.nswc.navy.mil Randy Miyazaki randy@lantron.com Doug Montgomery dougm@osi.ncsl.nist.gov Dennis Morris morris@altair.disa.mil Ismat Pasha ipasha@icm1.icp.net Alex Reijnierse a.a.l.reijnierse@research.ptt.nl Allen Rochkind Allen_Rochkind@3com.com Greg Ruth gruth@gte.com Dallas Scott scott@fluky.mitre.org Frank Solensky solensky@ftp.com Thuan Tran thuan@xylogics.com Scott Williamson scottw@nic.ddn.mil Jean Yao yao@cup.hp.com