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