The following text is copyright 1993 by Network World, permission is hearby given for reproduction, as long as attribution is given and this notice is included.

Whither IP?

By: Scott Bradner

Back in August I wrote about the not quite impending end of the Internet due to address exhaustion. At the end of that column I said "Use of CIDR does not obviate the need to choose a new IP, but by postponing the deadline for the choice, it will allow a more measured decision process." Well, saying things like that can get a body in trouble. As some of you may have read I've now been appointed co-director of a new temporary area within the IETF that is charged with making a recommendation on 'IP: next generation' (IPng), as it is now known.

On November 1st at the IETF meeting in Houston Texas, Allison Mankin (the other co-director) and I presented the procedure that we will follow in making this recommendation. It seemed to be reasonable to take this opportunity to describe that procedure here.

During the first phase of the process there will be five concurrent activities.

a/ Ascertain available time frame: A new IETF working group (Address Lifetime Expectations (ALE) ) has been formed to make estimates of the remaining useful lifetime of the address space used by the existing version of IP. The estimate will be made taking into account the use of CIDR, the changing address assignment policies and the availability of additional procedural documentation showing how to make more efficient use of assigned space. This group will also develop an understanding of the development and deployment time inherent in a switch to a new IP.

b/ Determine IPng requirements and technology availability. A second working group is being formed that will determine the set of features and functions that a new IP should support. Since some of the desired features will require additional research and development, realistic estimates will be made for the availability timeframe for each of the features.

c/ Develop strategies to deal with testing, transition and coexistence. A third working group will be formed to develop an understanding of the operational issues involved in the migration of the Internet to a new internet protocol. Particular emphasis will be placed on planning a testing process. There may be bugs in the initial set of standards and almost certainly there will be interoperability problems with the initial implementations. It is very important that by the time the new IP is deployed in a production network that it be as reliable as it can be. Since it is reasonable to expect that additional features will be added to IPng as time goes by (as features were added to the current IP), this group will be charged to create generic plans rather than target the existing proposals.

d/ Insure the best proposals. An extensive review process is being set up to ensure that the proposals for IPng are as good as they can be. An IPng choice should not be influenced by unclear or incomplete specifications. Each of the proposal documents will be first reviewed for clarity and completeness with the reviewers giving specific suggestions for improvement. Once the documents have passed muster in this phase they will be reviewed for technical feasibility. Note that this technical review is done within the context of the proposal, i.e., a reviewer cannot request changes just because of a disagreement over the width of the address, for example.

e/ White papers. In a new process for the IETF, the IPng area is inviting the submission of white papers from the wider networking community. The papers fall into two categories: they can help define the requirements for an IPng or they can offer solutions to the problems. These documents must follow a specific outline and are reviewed following the same procedures outlined above. They are used as resource material for the requirement and transition working groups and as an information repository. Each of the IPng proposals will be described in a white paper.

The IPng process is managed by the area co-directors assisted by a directorate recruited from a variety of sources. The directorate includes J. Allard (Microsoft), Steve Bellovin (AT&T), Jim Bound (Digital), Ross Callon (Wellfleet), Brian Carpenter (CERN), Dave Clark (MIT), John Curran (NEARnet), Steve Deering (Xerox), Dino Farinacci (Cisco), Paul Francis (Bellcore), Eric Fleischmann (Boeing), Daniel Karrenberg (RARE ), Mark Knopper (MERIT), Greg Minshall (Novell), Paul Mockapetris (ISI), Rob Ullmann (Lotus) and Lixia Zhang (Xerox). In addition, an expert review panel is being assembled and will be announced in the near future.

The initial phase described above is scheduled to be completed in April 1994. At that time the results of the ALE and requirements working groups will be combined to determine the final selection criteria. The proponents of each of the proposals will be asked to produce a white paper detailing how their proposal will meet the requirements and the associated timeframe. Public comment will be invited on these documents.

The final IPng selection with whatever specific suggestions may be warranted will be made by the area co-directors and ratified by IESG after an extended public review process. The selection is currently due to be presented at the IETF meeting in Toronto in July 1994.

Disclaimer of the month is from me - The above opinions are mine alone. In no way should it be assumed that anyone at Harvard shares them. (Though you are welcome to if they fit your own predilections)

ps - the archive for the IPng documents is on in pub/ipng for anonymous ftp

pps - Just to insure that there is no chance of any conflict of interest, I will donate my fee for this column to charity.