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The Architecture of the Common Indexing Protocol (CIP) (RFC2651) Disclosure Number: IPCOM000003240D
Original Publication Date: 1999-Aug-01
Included in the Prior Art Database: 2019-Feb-11
Document File: 19 page(s) / 27K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

J. Allen: AUTHOR [+1]

Related Documents

10.17487/RFC2651: DOI


This document describes the CIP framework, including its architecture and the protocol specifics of exchanging indices. [STANDARDS-TRACK]

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 8% of the total text.

Network Working Group J. Allen Request for Comments: 2651 WebTV Networks Category: Standards Track M. Mealling Network Solutions, Inc. August 1999

The Architecture of the Common Indexing Protocol (CIP)

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.


The Common Indexing Protocol (CIP) is used to pass indexing information from server to server in order to facilitate query routing. Query routing is the process of redirecting and replicating queries through a distributed database system towards servers holding the desired results. This document describes the CIP framework, including its architecture and the protocol specifics of exchanging indices.

1. Introduction

1.1. History and Motivation

The Common Indexing Protocol (CIP) is an evolution and refinement of distributed indexing concepts first introduced in the Whois++ Directory Service [RFC1913, RFC1914]. While indexing proved useful in that system to promote query routing, the centroid index object which is passed among Whois++ servers is specifically designed for template-based databases searchable by token-based matching. With alternative index objects, the index-passing technology will prove useful to many more application domains, not simply Directory Services and those applications which can be cast into the form of template collections.

Allen & Mealling Standards Track [Page 1]

RFC 2651 The CIP Architecture August 1999

The indexing part of Whois++ is integrated with the data access protocol. The goal in designing CIP is to extract the indexing portion of Whois++, while abstracting the index objects to apply more broadly to information retrieval. In addition, another kind of technology reuse has been undertaken by converting the ad-hoc data representations used by Whois++ into structures based on the MIME specification for structured Internet mail.

Whois++ used a version number field in centroid objects to facilitate future growth. The initial version was "1". Version 1 of CIP (then embedded in Whois++, and not referred to separately as CIP) had support for only ISO-8895-1 characters, and for only the centroid index object type.

Version 2 of the Whois++ centroid was used in the Digger software by Bunyip Information Systems to notify recipients that the centroid carried extra character set information. Digger’s centroids can carry UTF-8 encoded 16-bit Unicode characters, or ISO-8859-1 characters, determined by a field in the headers.

This specification is for CIP version 3. Version 3 is a major overhaul to the protocol. However, by using of a short negotiation sequence, CIP version 3 servers can int...