Internet Research Task Force                                  M. Eder
   Internet Draft                                             H. Chaskar
   Document: draft-irtf-smrg-ipsmf-00.txt                          Nokia
                                                                  S. Nag
   Category: Experimental                                   July 11, 2001



                 IP Service Management in the QoS Network


   Status of this Memo

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   Copyright Notice

   Copyright (C) The Internet Society (2001).  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 QoS-capable network envisioned by some for the
   future.   We examine some of the areas of impact QoS is likely to
   have on management and look at some questions that remain to be
   addressed.












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  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 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 paper 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 these new services represent 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].  IP, in
   contrast to other network technologies, does not limit the scope of
   service management simply to end-to-end connectivity, but combines
   service management with regards to transport with the management of
   the actual applications and how they are using the network.  If the
   available transport services in IP expand, this will result in 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

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   technologies based on fiber and wavelength-division multiplexing
   have many people convinced that bandwidth will be so inexpensive it
   is not going to be necessary to offer QoS. However uneconomical it
   is to engineer a network for peak usage, a major argument in this
   debate certainly is the cost of developing operational support
   systems for a QoS network and deploying them in the existing
   networks.  Just the fact that customers might be willing to pay for
   additional service may not be justification for implementing
   sweeping architectural changes that could seriously affect the
   Internet as it is known today.  The IP community must be very
   concerned that the equality that characterized the best effort
   Internet may be sacrificed in favor of a service that has a
   completely different business model. If the core network started to
   provide services that generated more revenue, its could easily come
   at the expense of the less revenue generating best effort service.

  3. IP Management Standardization

   Management standardization efforts in the IP community have
   traditionally been concerned with what is commonly referred to as
   "element management" or "device management".  Recently, new efforts
   in IP management have added the ability to address service issues
   and to look at the network in more abstract terms. These efforts
   which included a logical representation of services as well as the
   representation of resources in the network, combined with the notion
   of a user of a service, has made possible the much talked about
   concept of 'policy'.  Notable among these efforts are the Policy
   work in the IETF and the DMTF work on CIM and DEN.  Crucial elements
   of the service management framework are coming into perspective, but
   point to a trend in IP that is a quite radical departure from the
   control mechanisms of the past.  As the service model evolves from
   being what was sufficient to support best effort to being able to
   support variable levels of service, a trend towards a centralized
   management architecture has become quite apparent.

   This is becoming increasingly apparent for two reasons.  QoS
   mechanisms need network wide information [4], and for them to
   succeed, they must not require a tremendous amount of support from
   the core network.  It is becoming increasingly accepted that only at
   the edge of the network will there be sufficient resources to
   provide the mechanisms necessary to admit and control various QoS
   flows.

  4. Telecommunications Service Management

   One place to start an effort to define service management in IP
   networks is by looking at what was been done previously in
   telecommunications networks.  The telecommunications standards have
   not been very successful in defining an industry accepted service
   management framework even in an environment in which the service is
   fairly constrained.  Yet regulation has made it necessary for

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   network operators to open their networks sufficiently to allow for
   multiple vendor participation in providing the service.  This
   indicates that some formalized boundaries exist or the markets are
   sufficiently large to justify the development of interfaces.
   International telecommunications management standards look at the
   complete management problem by dividing it into separate but highly
   related layers.  Much of the terminology used to describe the
   management problem in IP has diffused from the telecommunications
   standards [5].  These standards were designed specifically to
   address telecommunications networks, and it is not clear how
   applicable they will be to IP networks.  Service management is
   defined in terms of the set of services found in telecommunications
   networks and the management framework reflects the hierarchical
   centralized control structure of these networks.  The framework for
   service management is based on the Telecommunications Management
   Network (TMN) layered approach to management.  Current IP standards
   are heavily weighted towards the element management layer and
   especially towards the gathering of statistical data with a
   decentralized approach being emphasized.  In TMN a dependency exists
   between layers and clear functions at their boundaries are defined.
   To what extent service management, as defined in the TMN standards,
   can be applied to IP which is lacking a network layer that supports
   a Logical Layered Architecture must be further investigated [5].

   TMN concepts must be applied carefully to IP networks because
   fundamental differences exist.  Control of IP networks is highly
   distributed especially in the network layer.  Management is non-
   hierarchical and decentralized with many peer-to-peer relationships.
   A formal division of management into layers, where management
   dependencies exist at the borders of these layers, may not be
   applicable to IP. Any effort to define service management in IP must
   be constantly vigilant that it does not assume the
   telecommunications concepts can be applied directly to IP networks.
   The most basic abstraction of the network management problem into
   element, network, and service management has as its origins in the
   telecommunications industry's standardization work.  The IP
   management framework might not have made even these distinctions if
   it where not for the telecommunications legacy.


  5. IP Service Management: Problem Statement

   In defining the Service Management Framework for IP, the nature of
   services that are going to need to be managed must be addressed.
   Traditionally network management frameworks consist of two parts, an
   informational framework and the proper framework architecture to
   enable management information to be distributed in the network
   environment.  The informational framework appears to be the easier
   problem to address and the one that is principally being focused on
   by the IP community.


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   Efforts by organizations such as the DMTF with their CIM and DEN
   initiatives are currently trying to define network, and to a lesser
   extent service, information models.  These efforts show a surprising
   similarity to those of the telecommunications industry to define
   information models [6].  What has not emerged is a clear framework
   for defining how the network management functionality will exist and
   how the information within the network domain and between domains
   will be exchanged.  Clearly the size of these networks will require
   this information to be highly distributed.

   There is a good deal of disagreement on this subject, but one would
   expect that highly distributed directories would be a prime
   candidate for the information that is of a static nature.  For
   information that is of a dynamic nature the problem becomes far more
   complex and has yet to be satisfactorily addressed.  Policy
   management is a logical extension of having distributed directories
   services available in the network.  The IETF and DMTF are looking to
   Policy management to be the framework by which certain service
   management issues can be addressed, primarily concentrating on those
   concerning access and traffic prioritization within a single
   administrative domain [7].

   Many of the current policy efforts are focused on classifying
   traffic flows and enforcing policies at the edge with the intent of
   focusing on admission issues, without addressing the end-to-end
   nature of the problem.  The full scope of problems associated with
   providing a commodity service that will need to be verifiable have
   not been addressed. A second issue with current policy efforts is
   the static nature in which they have been architect. Policies are
   not going to be functional if they cannot accommodate the dynamic
   nature of the network and its users.

   Standardization efforts need to concentrate on the management
   problems that are multi-domain in character.  The test for multi-
   domain often centers around there being a many-to-one or a one-to-
   many relationship requiring the involvement of two or more distinct
   entities.  Domains could reflect the administrative domain, routing
   domain, or include agreements between domains.   Element or device
   management does not meet the requirements for being multi-domain
   because the scope is primarily that of the device manufacturer.
   This may partially explain why it is proving to be not a very
   worthwhile candidate for standardization.  The implementation of
   element management systems standards have varied depending on the
   nature of the hardware and been pretty dependent on a particular
   manufacturers implementation.

   The problem with the domain model as it relates to IP networks is
   that so much of the traffic is likely to traverse multiple domains
   under separate administrative control.  Unlike the
   telecommunications network in which traffic traverses only a
   relatively small number of domains, IP traffic may traverse many

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   separately administered networks.  Further complicating the
   situation is, that unlike the telecommunications network many of
   these domains will be highly competitive in nature, offering and
   accommodating varying service level agreements.  Telecommunications
   traffic, even with deregulation, passes from the access providers
   network to a core network and then, if it is an international call,
   across international boundaries.  To be successful IP will need to
   model the domain problem in a way that reduces the complexity.

   A service management framework must address the business processes
   that operate when providing a service [5].  The processes a service
   framework must address can be separated into two fundamental
   divisions for any service.  The first is the definition of the
   service and the second is the management of an embodiment of the
   service.  While this division is intuitive, a formal process needs
   to be in place if management of the service is to be actually
   realized.

   In specifying a service, the service architecture must first be
   mapped onto the capabilities of the underlying network architecture.
   The service needs to be specified in an unambiguous way so that the
   mechanisms can be put in place to enable the control of the service.
   It can be a useful tool to view the relationship of the definition
   of a service to an instance of that service to the relationship
   between the definition of an object to the instantiation of that
   object in object oriented modeling.  Increasingly, as networks
   evolve it is going to be necessary to logically describe the network
   capabilities to the service.  As the IP networks become more
   fragmented it will be increasingly the case that specific service
   classifications will need to be made available.  A method that will
   allow for the logical definition of the network from a service
   perspective would allow for greater control of the network by the
   service management systems.   An ever increasing number of service
   specific devices are being added to the network.  These devices are
   often designed with management capabilities consistent with the
   services they offer.  It has been recognized that there exists a
   requirement for the user to have as much control over the management
   of the service as possible.  As the number and type of service
   specific devices increase in the network it will become important to
   provide management access to these devices over well understood
   methods.  IP services will need to be highly customizable
   necessitating that the management of the service be with the user to
   the extent possible.

   Paramount to the success of any service is determining how that
   service will be billed.  The process of billing must take place at
   the service inception.   It is here that the network support
   necessary for billing should be addressed.  Analogously, security
   must also be addressed  in the most early stages of the service
   definition.   It is not practical to assume that the billing and the
   security services will be hosted by the same provider as the service

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   itself or that it will be possible to have the billing and security
   functions specifically designed for every service.  These functions
   will have to be a generic part of the network.

   Given the limited success of telecommunications efforts to formalize
   the relationship between different management support functions it
   is highly suspect that such efforts would have any chance of
   succeeding in IP networks which have a more diverse concept of
   network and services.  If the IP network is to be made up of peer
   domains of equal dominion it will be necessary to have management
   functionality that is able to traverse these domains.   Of course
   the perspective of where management responsibility lies is largely
   dependent on the reference point.  A centric vantage point indicates
   responsibility shared equally among different domains.   From within
   any particular domain management responsibility exists within that
   domain and that domain only.   For a management framework to succeed
   in IP networks logical management functions will have to be
   identified along with an extremely flexible definition language to
   define the interface to these management functions.   The more the
   management functionality will have to cross boundaries of
   responsibility, the more the network management functions have to be
   distributed throughout the network.

  6. Core Inter-domain Functions

   The service management paradigm for IP must address management from
   a perspective that is a combination of technical solutions as well
   as a formula for representing vendor business relationships.
   Currently services that need support between domains require that
   the service level agreements (SLAs) be negotiated between the
   providers.   At some point these agreements will likely become
   unmanageable, if the number of agreements becomes very large and/or
   the nature of the agreements is highly variable. This will result in
   their being sufficient need for standardization or regulation to
   control these agreements resulting in it becoming no longer
   acceptable to make individual arrangements.

   Bandwidth Brokers have been conceived as a method for dealing with
   many of the problems between the domains relating to traffic from a
   business perspective. The premise of the Bandwidth Brokers is to
   insure agreement between the network domains with regards to
   traffic, but security and billing issues, that are not likely to be
   as quantifiable, will also need to be addressed.  Service providers
   have traditionally been reluctant to use bandwidth broker or SLA
   types of functions since they consider that such tools expose their
   weaknesses to competitors and customers.  While this is not a
   technical problem, it does pose a real practical problem in managing
   a service effectively.

   Looking at the basic requirements of the QoS network of the future
   two competing philosophies become apparent.  The network providers

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   are interested in having more control over the traffic to allow them
   to choose what traffic gets priority especially in a congested
   environment.  Users desire the ability to identify a path that has
   the characteristics very similar to a leased line [8].  In either
   situation as IP bandwidth goes from being delivered on a basis equal
   to all, to being delivered based on a particular authorities
   formula, there will become a need to provide authentication and
   validation.  This will include the ability to measure that service
   specified is being provided, to define the exact parameters of the
   service, and to verify that only an authorized level of service is
   being provided.

   Some of the earlier work on an architectural framework for mixed
   traffic networks has suggested that the only method that will work
   between administrative domains is that of bilateral agreement [9].
   Multilateral agreements may indeed be complex to administer, but
   another type of multilateral agreements exists that is not so
   complex.  This is the multilateral agreements mandated by means of
   national or international regulation.  Bilateral agreements will not
   scale well and if the traffic needs to traverse many administrative
   domains it will be hard to quantify the end-to-end service being
   provided. If the current instability in the ownership and
   administration of domains continues this will also limit the
   usability of bilateral agreements.  Only through a regulated process
   will it be possible to eliminate the effects competitive pressures
   will have on these types of agreements and make it possible to get a
   truly open environment.  Much pressure of a non-technical nature
   exists today to discourage this scenario.  If traffic agreements
   between the boundaries of networks is not mandated or standardized a
   continuing consolidation of network providers will result. Providers
   unable to induce other providers to pair with them will lose
   business if QoS networks become commonplace.  This result would be
   especially visible in its effects on small and midsize service
   providers.

   The majority of contemporary activity on higher level management
   functions for IP networks have been restricted to the issue of
   differentiating QoS with regards to transport.  Many service issues
   still remain to be resolved with respect to the current best effort
   paradigm and many more can be expected if true QoS support is
   realized.  Authentication, authorization and accounting services
   still inadequate for the existing best effort service will need
   additional work to support QoS services.

   It is reasonable that services can be classified into application
   level services and transport level services.  Transport services are
   the services that the network provides independent of any
   application. These include services such as Packet Forwarding and
   Routing, QoS, Traffic Engineering, RSVP/Intserv, Diffserv and MPLS.
   These might also include such functions as security (Ipsec) and
   Directory services.  In IP networks, QoS transport services can be

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   viewed as end-to-end (RSVP) or per-hop (Diffserv).  Transport level
   services tend to be unalterable requiring application level services
   to fit into the transport framework.  An application that needs a
   new transport level service will need to be a mass-market
   application where the investment in new infrastructure can be
   justified.  Because of the effort in altering transport services,
   applications that need new ones will have a longer time to market.
   The effort and cost to develop a framework necessary to support new
   transport services should not be underestimated.

   Application level services are those specific to the application.
   Many service management functions occur between the application
   supplier and  the application consumer which require no knowledge or
   support by the existing network.  By keeping service management
   functions at this level time to market and costs can be greatly
   reduced.  The disadvantages are that many applications need the same
   functionality causing inefficient use of the network resources.
   Transport services are able to be built more robustly and can
   provide additional functionality, by virtue of having access to
   information that applications can not, providing additional benefit
   over application level services.  An example of an application level
   service that could benefit from a transport service is the AAA
   paradigm for E-Commerce.  Sometimes application level service
   requirements have the disadvantages of both transport service and
   application service level.  For instance, in IP telephony, this may
   include services provided by a gateway or other network device
   specific to IP telephony to support such services as call forwarding
   or call waiting.  The mass appeal of IP telephony made it possible
   to suggest considerable infrastructure changes, but the nature of
   this kind of change has contributed to the slow penetration of IP
   telephony applications.

  7. A New Service Management Architecture

   An overview of the new management architectures shows a clear need
   for a consolidated framework.  Transport level QoS will demand
   traffic engineering that has a view of the complete network that is
   far more comprehensive than what is currently available via the
   Routing protocols, including network dynamics and network congestion
   information in the networks at a given instant of time, for the
   network administrator to take appropriate actions at any given
   instant.  The current existing best-effort transport control plane
   may become more of a hindrance to new services and may be of
   questionable value if the IP network will truly become a full
   service QoS network.  Both IntServ and DiffServ QoS schemes require
   network administrators to provision their networks to support QoS
   within a particular domain  and to establish SLAs for traffic
   traversing domains.  In reality, very few administrators would be
   able to understand the complexities of such a task and would simply
   accept the factory default settings with the expectation that these
   would provide adequate operations.  Policy management, object

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   oriented information models, and domain gateways are leading to a
   need for a more centralized management structure that is no less
   automated than the infrastructure of the past but provides an
   approach able to insure full service throughout the network and
   across domains. Given the probable cost and complexity of such a
   system failure to come up with a standard, even if it is a de facto
   standard, will have serious implications for the Internet in the
   future.

   For the current trends in QoS to succeed, there will need to be
   harmonization across the new and existing control structures.  By
   utilizing a structure very similar to the existing routing control
   structures, it should be possible develop functionality, not in the
   data path, that can allocate traffic within a domain and use inter-
   domain signaling to distribute between domains.   Additional
   functionality, necessary to support QoS-like authorization and
   authentication functions for edge devices admitting QoS traffic and
   administering and allocating traffic between administrative domains
   could also be supported.  While meeting the requirements for a
   bandwidth broker [9], additional functionality of making more
   general policy decisions and QoS routing could also be performed.
   Given that these tasks are interrelated it makes sense to integrate
   them if possible.

   The architecture is based on a centrally located functionality
   responsible for allocating traffic within a particular
   administrative domain and capable of signaling traffic requirements
   across domains.  This would be accomplished by redirecting routing
   messages to the central functionality which would then calculate
   paths based on the entire network and the transport requirements.
   Routing messages, very similar in content to the existing ones,
   would provide information sufficient to support the traffic
   engineering requirements without changing the basic forwarding
   functions of the devices.  Having routes computed centrally would
   simplify the network devices and release them from performing
   computationally intensive routing related tasks.

   Given the growth of the Internet, for scalability reasons the core
   can not know about flow states [10], and this information can be
   known only in the edge routers.  As the information needed to
   forward traffic through the network becomes more and more related to
   complex parameters that have nothing to do with the forwarding of
   packets, which routers do best, it makes less and less sense to have
   the determination of routes as a component of a routers functions.
   In a QoS network routing decisions become increasingly dependent on
   information not easily discernable from the data that routers can
   logically share between themselves.  This will necessitate the need
   for additional functionality to determine the routing of data
   through the network and further suggests that all the information
   needed to allow a router to forward packets might not be better
   provided external to the routers functions.

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   At the edges of the network where the traffic is admitted it will be
   necessary to have mechanisms that will insure the traffic is within
   the bounds of what has been specified.  To achieve this
   functionality, it will be necessary to buffer and control the input
   traffic.  Second the traffic would need to be marked so the other
   network elements would be aware that this was the preferred traffic.
   Conversely, a path could be chosen for this traffic that was
   dedicated to the level of service being requested.  Some combination
   of these two would be possible.  In fact these two methods are more
   similar than they first appear from a management perspective.  Both
   are really identical in that one is just a virtual path based on the
   handling of the packets by the device in the network and the second
   would be more a pre-configured path through the network.  It can not
   be expected that the existing best effort routing will provide the
   optimum routes for these new levels of service.  To achieve this it
   would be necessary to have either routing protocols that supported
   optimum path discovery or mechanisms to configure paths necessary to
   support the required services.

   There are implications of providing shaping at the network
   boundaries.  Shaping would include both rate and burst parameters.
   Having to provision services, that cannot be over subscribed, would
   present both major business and technical problems. By definition,
   packet data is bursty in nature and there exist long periods of
   idleness during the session.  It is not practical to expect a
   consumer paying a premium for a service would not check that the
   service was truly available.  Such a service model seems to be
   filled with peril for the existing best effort Internet if any
   significant amount of the bandwidth was reserved for exclusive use.

   Clearly with respect to traffic within the network itself there will
   be the need to pre-configure routes and to provide the ability to
   have routes be dynamically configured.  Each is complex in itself.
   Some of the problems with pre-configured traffic include it's basic
   inconsistency with the way traffic is currently engineered through
   the Internet and the difficulty in developing arrangements between
   administrative domains.  The current Internet has been developed
   with one of the most egalitarian yet simplistic methods of sharing
   bandwidth.  Supporting the existing best effort service, in an
   unbiased way, while at the same time providing for other classes of
   service could potentially add a tremendous amount of complexity to
   the QoS scheme.  On the other hand, if the reserved bandwidth is not
   shared it could result in a significant impact on the availability
   of the bandwidth in the Internet as we know it today.  QoS could
   potentially contribute more to their being insufficient bandwidth,
   by reserving bandwidth within the network that can not be used by
   other services, even though it can be expected that this bandwidth
   will be underutilized for much of the time.  Add to that the
   motivation of the service providers in wanting to sell commodity


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   bandwidth, and that could be tremendous pressures on the
   availability of Internet bandwidth.

   Current work within the IP community on defining mechanisms to
   provide QoS have centered on a particular few architectures and a
   handful of new protocols.  In the following sections, we will
   examine some of the particular issues with regards to the current IP
   community efforts as they relate to the previous discussions.  It is
   not the goal of this paper to serve as a tutorial on these efforts
   but rather to identify some of the support issues related to using
   particular technologies that support some form of classifiable
   service within an IP network.

  8. The DiffServ Architecture

   The DiffServ management problem is two pronged.  First there is the
   management within the administrative domain that must be addressed,
   and then the management between the domains.  The second is
   certainly easier to address because there has been little actual
   work on this aspect of the architecture.  What work there has been
   anticipates that service level agreements will be reached between
   the administrative domains, and that end-to-end service will be a
   concatenation of these various service level agreements.  This is
   problematic for many reasons.  From the business perspective, it
   presumes that agreements reached bilaterally could be concatenated
   and continue to provide a level of end-to-end service the customer
   would be willing to pay a premium for.  Market conditions mentioned
   earlier with trying to maintain large numbers of these agreements
   between competitive networks would also apply.

   Guaranteeing a class of service on a per hop basis is in no way a
   guarantee of the service on an end-to-end basis.  It is not likely
   that a customer would be willing to pay for an improved level of
   service if it did not include guarantees on the bandwidth and the
   quantitative bounds on delay and error rates guaranteed end-to-end.
   While it is very likely that an initial attempt at providing this
   kind of service will specify only a particular ingress and egress
   border, for robustness and flexibility it will be desirable to have
   a network that can support such service without such limitations.
   The Intserv approach, as opposed to the DiffServ architecture, would
   require too much per flow and overhead information in the core
   network and not be scaleable [10].  A DiffServ type architecture,
   with a limited number of service classes, could be pre-provisioned,
   and as network circumstances warranted, be modified to support the
   actual dynamics of the network.

   The high level functional requirements for edge routers has been
   quite well defined in the DiffServ architecture, but the true scope
   of the effort to implement this functionality has not been well
   recognized.  While interesting differences exist between the QoS
   architecture of the Internet and the circuit switched network used

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   for telecommunications much of the lessons learned in
   telecommunications should, even if they might do little else,
   provide some insight into the level of effort needed to implement
   these kinds of requirements.  Ironically, given the Internet
   community in the past has rejected the level of standardization that
   was proposed for management of telecommunications networks, it may
   be the full service internet where it becomes actually imperative
   that such requirements be completed if the desired services will
   ever be offered.

  9. Common QoS Functional Areas

   The management of QoS will need to provide functionality to the
   application and/or at the access, at the core, and at the boundaries
   to administrative regions.

   QoS traffic functions will need to include admission control,
   authentication and authorization, and billing.  Verification that
   traffic is within agreed parameters and programmatic interfaces to
   advise when the service is outside the agreed limits.  Interfaces
   that provide service verification, fault notification, and re-
   instantiation and termination will also be necessary.

   Core functions will include traffic engineering, network device
   configuration, fault detection, and recovery.  Network devices will
   need to inform the management system of their available resources
   and the management system will need to tell devices how and where to
   forward data.

   Between administrative regions accounting, service signaling,
   service verification will be needed.  At the administrative
   boundaries of the network functions similar to those provided at the
   edge will be necessary.  Peer entities in different administrative
   domains would signal their needs across the boundary.  Verification
   at the boundary could then occur consistent with the verification at
   the edge.  Actual traffic through the boundaries could be measured
   and billing information be transferred between the domains.  The
   central management function would be responsible for re-routing
   traffic in the event of a failure or to better utilize the existing
   network resources.


  10.    Summary

   The paradigm for service management in IP networks has been adopted
   from that of telecommunications networks.  Basic differences between
   the service models of these networks call into question if this is
   realistic.  Further analysis is needed to determine what is the
   proper paradigm for IP service management and to define a common
   vocabulary for it.


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   The IP community is currently very active in solving problems
   relating to transport QoS issues.  These activities are illustrated
   by the work of the Diffserv, Intserv, and Policy working groups.  In
   contrast not enough effort is being focused on service issues
   relating to applications.  The present solution is for applications
   to build in their own service management functionality.  This is
   often an inefficient use of network resources, but more importantly
   will not provide for access to transport level services and the
   functionality that only those services will offer.

   The IP community needs to focus on adding service functionality that
   is flexible enough to be molded to specific application needs, yet
   will have assess to transport information that will be necessary to
   provide superior application functionality.  Principal needs to be
   addressed relate to developing transport level services for billing
   and security.  Directory services and extending the work done to
   define AAA services are promising starting points for developing
   this needed functionality.

  11.    Authors

   Michael Eder
     Nokia Research Center
     5 Wayside Road
     Burlington,  MA  01803
     Phone:    +1-781-993-3636
     Fax:      +1-781-993-1907
     E-mail:   Michael.eder@nokia.com

   Sid Nag
     PO Box 104
     Holmdel, NJ 07733
     Phone:    +1-732-687-1762
     E-mail:   thinker@monmouth.com

   Hemant Chaskar
     Nokia Research Center
     5 Wayside Road
     Burlington,  MA  01803
     Phone:    +1-781-993-3785
     Fax:      +1-781-993-1907
     E-mail:   hemant.chaskar@nokia.com










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  12.    References


   [1]   Laurent Mathy, Christopher Edwards, David Hutchison, "The
   Internet: A Global Telecommunications Solution?", IEEE Network,
   July/August 2000.

   [2]   Barry M. Leiner, Vinton G. Cerf, et. al., ôA Brief History of
   the Internetö version 3.31, revised 4 Aug 2000

   [3]   J. Strassner and E. Ellesson, "Terminology for describing
   network policy and services", draft-ietf-policy-terms-02.txt, June
   1999.

   [4]   Yoram Bernet, "The Complementary Roles of RSVP and
   Differentiated Services in the Full-Service QoS Network", IEEE
   Communications Magazine, February 2000

   [5]   Recommendation M.3010 (02/00) - Principles for a
   telecommunications management network, ITU-T

   [6]   Recommendation M.3100 (07/95) - Generic network information
   model, ITU-T

   [7]   B. Moore, et. al., "Policy Core Information Model -- Version
   1 Specification", IETF, RFC 3060, February 2001

   [8]   Van Jacobson, Differentiated Services for the Internet,
   Internet2 Joint Applications/Engineering QoS Workshop

   [9]   K. Nichols, V. Jacobson, L. Zhang, A Two-bit Differentiated
   Services Architecture for the Internet, RFC 2638, July 1999

   [10]  Mankin, A., Baker, F., Braden, R., O'Dell, M., Romanow, A.,
   Weinrib, A. and L. Zhang, "Resource ReSerVation Protocol (RSVP)
   Version 1 Applicability Statement", RFC 2208, September 1997.















   Eder, Nag, Chaskar                                              15