RFC 1809 (rfc1809) - Page 1 of 6

Using the Flow Label Field in IPv6

Network Working Group                                       C. Partridge
Request for Comments: 1809                  BBN Systems and Technologies
Category: Informational                                        June 1995



                   Using the Flow Label Field in IPv6


Status of this Memo

   This memo provides information for the Internet community.  This memo
   does not specify an Internet standard of any kind.  Distribution of
   this memo is unlimited.

Abstract

   The purpose of this memo is to distill various opinions and
   suggestions of the End-to-End Research Group regarding the handling
   of Flow Labels into a set of suggestions for IPv6.  This memo is for
   information purposes only and is not one of the IPv6 specifications.
   Distribution of this memo is unlimited.

Introduction

   This memo originated as the report of a discussion at an End-to-End
   Research Group meeting in November 1994.  At that meeting the group
   discussed several issues regarding how to manage flow identifiers in
   IPv6.   A report of the meeting was then circulated to the IPv6
   community.  Feedback from that community resulted in changes to this
   memo and in changes to the IPv6 specification to fix some minor
   problems the End-to-End Group had raised.

   While many of the ideas in this memo have found their way into the
   IPv6 specification, the explanation of why various design decisions
   were made have not.  This memo is intended to provide some additional
   context for interested parties.

Brief Description of the Flow Label

   The current draft of the IPv6 specification states that every IPv6
   header contains a 24-bit Flow Label.  (Originally the specification
   called for a 28-bit Flow ID field, which included the flow label and
   a 4-bit priority field.  The priority field is now distinct, for
   reasons discussed at the end of this memo).






Partridge                    Informational