RFC 2227 (rfc2227) - Page 1 of 37

Simple Hit-Metering and Usage-Limiting for HTTP

Network Working Group                                           J. Mogul
Request for Comments: 2227                                        DECWRL
Category: Standards Track                                       P. Leach
                                                               Microsoft
                                                            October 1997


            Simple Hit-Metering and Usage-Limiting for HTTP

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 (1997).  All Rights Reserved.

ABSTRACT

   This document proposes a simple extension to HTTP, using a new
   "Meter" header, which permits a limited form of demographic
   information (colloquially called "hit-counts") to be reported by
   caches to origin servers, in a more efficient manner than the
   "cache-busting" techniques currently used.  It also permits an origin
   server to control the number of times a cache uses a cached response,
   and outlines a technique that origin servers can use to capture
   referral information without "cache-busting."

TABLE OF CONTENTS

   1 Introduction                                                      2
        1.1 Goals, non-goals, and limitations                          3
        1.2 Brief summary of the design                                4
        1.3 Terminology                                                5
   2 Overview                                                          5
        2.1 Discussion                                                 7
   3 Design concepts                                                   8
        3.1 Implementation of the "metering subtree"                   8
        3.2 Format of the Meter header                                10
        3.3 Negotiation of hit-metering and usage-limiting            10
        3.4 Transmission of usage reports                             14
        3.5 When to send usage reports                                15
        3.6 Subdivision of usage-limits                               16




Mogul & Leach               Standards Track