RFC 4148 and the IPPM Metrics Registry are Obsolete
draft-morton-ippm-rfc4148-obsolete-02

Abstract

This memo recommends that RFC 4148, the IP Performance Metrics (IPPM) Registry be reclassified as Historic, and the IANA IPPM Metrics Registry itself be withdrawn from use. The current registry structure has been found to be insufficiently detailed to uniquely identify IPPM metrics. Despite apparent efforts to find current or even future users, no one has responded to the third quarter of 2010 call for interest in the RFC 4148 registry.

Requirements Language

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 RFC 2119 (Bradner, S., “Key words for use in RFCs to Indicate Requirement Levels,” March 1997.) [RFC2119].

Status of this Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at http://datatracker.ietf.org/drafts/current/.

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This Internet-Draft will expire on April 28, 2011.

Copyright Notice

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Table of Contents

1.  Introduction
2.  Recommendation to Reclassify RFC 4148 and Withdraw the corresponding IANA registry
3.  Security Considerations
4.  IANA Considerations
5.  Acknowledgements
6.  References
    6.1.  Normative References
    6.2.  Informative References
§  Author's Address

1.  Introduction

The IP Performance Metrics (IPPM) framework [RFC2330] (Paxson, V., Almes, G., Mahdavi, J., and M. Mathis, “Framework for IP Performance Metrics,” May 1998.) describes several ways to record options and metric parameter settings, in order to account for sources of measurement variability. For example, Section 13 of[RFC2330] (Paxson, V., Almes, G., Mahdavi, J., and M. Mathis, “Framework for IP Performance Metrics,” May 1998.) describes the notion of "Type P" so that metrics can be specified in general, but the specifics (such as payload length in octets and protocol type) can replace P to disambiguate the results.

When the IPPM Metric Registry [RFC4148] (Stephan, E., “IP Performance Metrics (IPPM) Metrics Registry,” August 2005.) was designed, the variability of the Type P notion, and the variability possible with the many metric parameters (see Section 4.1 of [RFC2679] (Almes, G., Kalidindi, S., and M. Zekauskas, “A One-way Delay Metric for IPPM,” September 1999.) ) was not fully appreciated. Further, some of the early metric definitions only indicate Poisson streams [RFC2330] (Paxson, V., Almes, G., Mahdavi, J., and M. Mathis, “Framework for IP Performance Metrics,” May 1998.) (see the metrics in [RFC2679] (Almes, G., Kalidindi, S., and M. Zekauskas, “A One-way Delay Metric for IPPM,” September 1999.), [RFC2680] (Almes, G., Kalidindi, S., and M. Zekauskas, “A One-way Packet Loss Metric for IPPM,” September 1999.), and [RFC3393] (Demichelis, C. and P. Chimento, “IP Packet Delay Variation Metric for IP Performance Metrics (IPPM),” November 2002.)), but later work standardized the methods for Periodic Stream measurements [RFC3432] (Raisanen, V., Grotefeld, G., and A. Morton, “Network performance measurement with periodic streams,” November 2002.), adding to the variability possible when characterizing a metric exactly.

It is not believed to be feasible or even useful to register every possible combination of Type P, metric parameters, and Stream parameters using the current structure of the IPPM Metric Registry.

The IPPM Metrics Registry is believed to have very few, if any users. Evidence of this provided by the fact that one registry entry was syntactically incorrect for months after [RFC5644] (Stephan, E., Liang, L., and A. Morton, “IP Performance Metrics (IPPM): Spatial and Multicast,” October 2009.) was published. The text ":=" was used for the metrics in that document instead of "::=". It took eight months before someone complained that a parser found the error. Even the original registry author agrees that the current registry is not efficient, and has submitted a proposal to effectively create a new registry [draft-stephan-ippm-registry-ext-00, work in progress].

Despite apparent efforts to find current or even future users, no one has responded to the third quarter of 2010 call for interest in the RFC 4148 registry. Therefore, the IETF could now declare the registry Historic without any further reservations.

When a registry is declared Historic, it simply prevents IANA from registering new objects, in this case new metrics. So, even if a registry user was eventually found, they could continue to use the current registry and its contents will continue to be available.

2.  Recommendation to Reclassify RFC 4148 and Withdraw the corresponding IANA registry

Due to the ambiguities between the current metrics registrations and the metrics used, and the apparent minimal adoption of the registry in practice, this memo RECOMMENDS that:

• the IETF reclassify [RFC4148] (Stephan, E., “IP Performance Metrics (IPPM) Metrics Registry,” August 2005.) as Historic
• the IANA withdraw the current IPPM Metrics Registry

It is assumed that parties who wish to establish a replacement registry function will work to specify such a registry.

3.  Security Considerations

This memo and its recommendations have no known impact on the security of the Internet (especially if there is a zombie apocalypse on the day it is published; humans will have many more security issues to worry about stemming from the rise of the un-dead).

4.  IANA Considerations

Metrics defined in IETF are typically registered in the IANA IPPM METRICS REGISTRY as described in initial version of the registry [RFC4148] (Stephan, E., “IP Performance Metrics (IPPM) Metrics Registry,” August 2005.). However, areas for improvement of this registry have been identified, and the registry structure has to be revisited when there is consensus to do so.

The current consensus is to withdraw the IPPM Metrics Registry, as originally described in [RFC4148] (Stephan, E., “IP Performance Metrics (IPPM) Metrics Registry,” August 2005.).

5.  Acknowledgements

Henk Uijterwaal suggested additional rationale for the recommendation in this memo.

6.  References

6.1. Normative References

6.2. Informative References

Author's Address