Network Working Group K. Holtman
Request for Comments: 2296 TUE
Category: Experimental A. Mutz
Hewlett-Packard
March 1998
HTTP Remote Variant Selection Algorithm -- RVSA/1.0
Status of this Memo
This memo defines an Experimental Protocol for the Internet
community. It does not specify an Internet standard of any kind.
Discussion and suggestions for improvement are requested.
Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (1998). All Rights Reserved.
ABSTRACT
HTTP allows web site authors to put multiple versions of the same
information under a single URL. Transparent content negotiation is a
mechanism for automatically selecting the best version when the URL
is accessed. A remote variant selection algorithm can be used to
speed up the transparent negotiation process. This document defines
the remote variant selection algorithm with the version number 1.0.
TABLE OF CONTENTS
1 Introduction...............................................2
2 Terminology and notation...................................2
3 The remote variant selection algorithm.....................2
3.1 Input....................................................2
3.2 Output...................................................3
3.3 Computing overall quality values.........................3
3.4 Definite and speculative quality values..................5
3.5 Determining the result...................................6
4 Use of the algorithm.......................................7
4.1 Using quality factors to rank preferences................7
4.2 Construction of short requests...........................8
4.2.1 Collapsing Accept- header elements.....................8
4.2.2 Omitting Accept- headers...............................9
4.2.3 Dynamically lengthening requests.......................9
4.3 Differences between the local and the remote algorithm..10
4.3.1 Avoiding major differences............................11
4.3.2 Working around minor differences......................11
Holtman & Mutz Experimental