RFC 2673 (rfc2673) - Page 1 of 7

Binary Labels in the Domain Name System

Network Working Group                                        M. Crawford
Request for Comments: 2673                                      Fermilab
Category: Standards Track                                    August 1999


                Binary Labels in the Domain Name System

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (1999).  All Rights Reserved.

1.  Introduction and Terminology

   This document defines a "Bit-String Label" which may appear within
   domain names.  This new label type compactly represents a sequence of
   "One-Bit Labels" and enables resource records to be stored at any
   bit-boundary in a binary-named section of the domain name tree.

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [KWORD].

2.  Motivation

   Binary labels are intended to efficiently solve the problem of
   storing data and delegating authority on arbitrary boundaries when
   the structure of underlying name space is most naturally represented
   in binary.

3.  Label Format

   Up to 256 One-Bit Labels can be grouped into a single Bit-String
   Label.  Within a Bit-String Label the most significant or "highest
   level" bit appears first.  This is unlike the ordering of DNS labels
   themselves, which has the least significant or "lowest level" label
   first.  Nonetheless, this ordering seems to be the most natural and
   efficient for representing binary labels.






Crawford                    Standards Track