Signaled Preemption Priority Policy Element (RFC3181)

Network Working Group S. Herzog Request for Comments: 3181 PolicyConsulting.Com Obsoletes: 2751 October 2001 Category: Standards Track

Signaled Preemption Priority Policy Element

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 (2001). All Rights Reserved.

Abstract

This document describes a preemption priority policy element for use by signaled policy based admission protocols (such as the Resource ReSerVation Protocol (RSVP) and Common Open Policy Service (COPS).

Preemption priority defines a relative importance (rank) within the set of flows competing to be admitted into the network. Rather than admitting flows by order of arrival (First Come First Admitted) network nodes may consider priorities to preempt some previously admitted low priority flows in order to make room for a newer, high- priority flow.

This memo corrects an RSVP POLICY_DATA P-Type codepoint assignment error in RFC 2751.

Herzog Standards Track [Page 1]

RFC 3181 Signaled Preemption Priority Policy Element October 2001

Table of Contents

1 Introduction .....................................................2 2 Scope and Applicability ..........................................3 3 Stateless Policy .................................................3 4 Policy Element Format ............................................4 5 Priority Merging Issues ..........................................5 5.1 Priority Merging Strategies ...................................6 5.1.1 Take priority of highest QoS .................................6 5.1.2 Take highest priority ........................................7 5.1.3 Force error on heterogeneous merge ...........................7 5.2 Modifying Priority Elements ...................................7 6 Error Processing .................................................8 7 IANA Considerations ..............................................8 8 Security Considerations ..........................................8 9 References .......................................................9 10 Author’s Address ...............................................9 Appendix A: Example ...............................................10 A.1 Computing Merged Priority ....................................10 A.2 Translation (Compression) of Priority Elements ...............11 Full Copyright Statement ..........................................12

1 Introduction

This document describes a preemption priority policy element for use by signaled policy based admission protocols (such as [RSVP] and [COPS]).

Traditional Capacity based Admission Control (CAC) indiscriminately admits new flows until capacity is exhausted (First Come First Adm...