Re: Call for presentations

[Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp>]

Kurt;

> With this mail I would like to ask for presentations for the first slot 
> of the multi6 WG.
> 
> Please send me
> 
> - - Presenters name
Masataka Ohta
> - - Draft name
draft-ohta-multihomed-isps-00.txt (just submitted)
> - - Rough time estimate needed
10 min.

The draft is attached.

						Masataka Ohta






INTERNET DRAFT                                                   M. Ohta
draft-ohta-multihomed-isps-00.txt          Tokyo Institute of Technology
                                                               June 2003

                   Multihomed ISPs and Policy Control

Status of this Memo

   This document is an Internet-Draft and is subject to all provisions
   of Section 10 of RFC2026.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-
   Drafts.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet- Drafts as reference
   material or to cite them other than as "work in progress."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/1id-abstracts.html

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html

Abstract

   Policy control of next level ISPs, delegated address spaces from top
   level ISPs, is discussed.

   While global policy coodination requires top level aggregators, local
   policy can be controlled with next level aggregators.

1. Introduction

   Considering that some people has been arguing to have 4 byte AS
   numbers, the number of ISPs will grow indifinitely

   On the other hand, having small number of TLIs will make full routing
   table small that it can be expected that most hosts has full routing
   table, reducing the problems with destination and source address
   selection.

   An obvious solution is to have layers of ISPs, as was specified in
   IPv6 to have TLA (Top Level Aggregator) and NLA (Next Level
   Aggregator) that they can be allocated to TLIs (Top Level ISPs) and



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   NLIs (Next Level ISPs, correspondingly.

   The probelm, however, is whethere and how the number of TLIs can be
   controlled.

2. Robustness

   An essential property of ISPs is robustness of its service that it is
   almost mandately that NLIs are multihomed to multiple TLIs.

   It is, then, expected that some sites are multihomed to multiple TLIs
   and/or NLIs.

   It is expected that NLIs have multiple prefixes each belonging to
   multiple TLAs, all of which is delegated to sites.

3. BGP Policy Control

   BGP Policy is controlled by identifying ISPs not by address prefix
   but by AS numbers.

   Thus, a next level ISP not having its own TLA can still fully control
   its policy.

   Moreover, neighbour ISPs can adjust their policy using the full
   prefix of the ISP.

   However, to limit the size of global routing table, an AS and
   prefixes of the next level ISP at the distance must be discarded or
   merged with its TLA.

   But, it is better than a current multihoming practice that prefix of
   a multihomed site is propagated locally to give robustness against
   local failures, because multiple TLAs give robustness against global
   failures.

   Thus, it is not essential that ISPs have their own TLAs.

4. Limiting the Number of TLAs.

   There should be hard upper bound on the number of TLAs in the
   Internet.

   For example, some TLA may be supplied from RIRs with bidding.

   Some TLA may be allocated to each country (proportional to the
   population of the country) and delivered with the countrie's policy.




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   The proper number of TLAs, it seems to the author, should be
   somewhere between 1024 and 8192.

5. Author's Address

   Masataka Ohta
   Graduate School of Information Science and Engineering
   Tokyo Institute of Technology
   2-12-1, O-okayama, Meguro-ku, Tokyo 152-8552, JAPAN

   Phone: +81-3-5734-3299
   Fax: +81-3-5734-3299
   EMail: mohta@necom830.hpcl.titech.ac.jp






































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