Considerations from the Service Management Research Group (SMRG) on Quality of Service (QoS) in the IP Network
RFC 3387

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Network Working Group                                            M. Eder
Request for Comments: 3387                                    H. Chaskar
Category: Informational                                            Nokia
                                                                  S. Nag
                                                          September 2002

    Considerations from the Service Management Research Group (SMRG)
             on Quality of Service (QoS) in the IP Network

Status of this Memo

   This memo provides information for the Internet community.  It does
   not specify an Internet standard of any kind.  Distribution of this
   memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2002).  All Rights Reserved.

Abstract

   The guiding principles in the design of IP network management were
   simplicity and no centralized control.  The best effort service
   paradigm was a result of the original management principles and the
   other way around.  New methods to distinguish the service given to
   one set of packets or flows relative to another are well underway.
   However, as IP networks evolve the management approach of the past
   may not apply to the Quality of Service (QoS)-capable network
   envisioned by some for the future.  This document examines some of
   the areas of impact that QoS is likely to have on management and look
   at some questions that remain to be addressed.

1. Introduction

   Simplicity above all else was one of the guiding principles in the
   design of IP networks.  However, as IP networks evolve, the concept
   of service in IP is also evolving, and the strategies of the past may
   not apply to the full-service QoS-capable network envisioned by some
   for the future.  Within the IP community, their exists a good deal of
   impetus for the argument that if the promise of IP is to be
   fulfilled, networks will need to offer an increasing variety of
   services.  The definition of these new services in IP has resulted in
   a need for reassessment of the current control mechanism utilized by
   IP networks.  Efforts to provide mechanisms to distinguish the
   service given to one set of packets or flows relative to another are
   well underway, yet many of the support functions necessary to exploit
   these mechanisms are limited in scope and a complete framework is

Eder, et. al.                Informational                      [Page 1]
RFC 3387        IP Service Management in the QoS Network  September 2002

   non-existent.  This is complicated by the fact that many of these new
   services will also demand some form of billing framework in addition
   to a control one, something radically new for IP.

   This document intends to evaluate the network and service management
   issues that will need to be addressed, if the IP networks of the
   future are going to offer more than just the traditional best effort
   service in any kind of significant way.

2. Background

   The task of defining a management framework for QoS will be difficult
   due to the fact that it represents a radical departure from the best
   effort service model that was at the core of IP in the past, and had
   a clear design strategy to have simplicity take precedence over
   everything else [1].  This philosophy was nowhere more apparent than
   in the network and service management area for IP [2].  Proposed
   changes to support a variety of QoS features will impact the existing
   control structure in a very dramatic way.  Compounding the problem is
   the lack of understanding of what makes up a "service" in IP [3].
   Unlike some other network technologies, in IP it does not suffice to
   limit the scope of service management simply to end-to-end
   connectivity, but the transport service offered to packets and the
   way the transport is used must also be covered.  QoS management is a
   subset of the more general service management.  In looking to solve
   the QoS management problem it can be useful to understand some of the
   issues and limitations of the service management problem.  QoS can
   not be treated as a standalone entity and will have its management
   requirements driven by the general higher level service requirements.
   If the available transport services in IP expand, the result will be
   the further expansion of what is considered a service.  The now
   de-facto inclusion of WEB services in the scope of IP service, which
   is remarkable given that the WEB did not even exist when IP was first
   invented, illustrates this situation well.  This phenomenon can be
   expected to increase with the current trend towards moving network
   decision points towards the boundary of the network and, as a result,
   closer to the applications and customers.  Additionally, the argument
   continues over the need for QoS in IP networks at all.  New
   technologies based on fiber and wavelength-division multiplexing have
   many people convinced that bandwidth will be so inexpensive it is not