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rfc:rfc1346

Network Working Group P. Jones Request for Comments: 1346 Joint Network Team, UK

                                                             June 1992
           Resource Allocation, Control, and Accounting
                  for the Use of Network Resources

Status of this Memo

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

0. MANAGEMENT SUMMARY

 This paper gives reasons for wanting better sharing mechanisms for
 networks.  It concludes that the challenge of sharing network
 resources (and for example intercontinental link resources) between
 groups of users is neither well understood, nor well catered for in
 terms of tools for those responsible for managing the services.  The
 situation is compared with other fields, both inside and outside IT,
 and examples are cited. Recommendations for further work are made.
 The purpose of this RFC is to focus discussion on particular
 challenges in large service networks in general, and the
 International IP Internet in particular.  No solution discussed in
 this document is intended as a standard.  Rather, it is hoped that a
 general consensus will emerge as to the appropriate solutions,
 leading eventually to the adoption of standards.
 The structure of the paper is as follows:
    1. Findings
    2. Conclusions
    3. Recommendations

1. FINDINGS

 Issues arising from contention in the use of networks are not
 unusual.  Once connectivity and reliability have been addressed to a
 reasonable level, bandwidth becomes (or appears to become?) the main
 issue.  Usage appears to have a strong tendency to rise to fill the
 resources available (fully in line with the principles of Parkinson's
 Law).  Line-speed upgrades have an effect, but with no guarantee of
 permanently alleviating the problem.  Line-speeds are increasing as
 technology improves over time, but the variations on matters like
 availability and funding are wide, and users remain avaricious.

Jones [Page 1] RFC 1346 Resource Allocation, Control, and Accounting June 1992

 Often the situation can appear worse than having to survive in a
 jungle, in the sense that the strong (even if "good") seem to have
 little advantage over the weak.  It may seem that it is the
 determined person rather than the important work that gets service.
 Most people will have experienced poor service on an overloaded
 network at some time. To help the end-users, it seems on the face of
 it that one must help the IT Service Manager he relates to.  Examples
 relating to the relationship between the network manager and his
 customers, IT Service Managers at institutions connecting to his
 network, include the following:
 (a) If the IT Service Manager finds his link to the Network Manager's
 network overloaded, he may be offered a link upgrade, probably with a
 cost estimate.  He might prefer control mechanisms whereby he can say
 that department X deserves more resources than department Y, or that
 interactive terminal use takes preference over file transfers, or
 that user U is more important than user V.
 (b) Where an IT Service Manager is sharing a link, he will commonly
 get more than his institution's share of the link, and often get very
 good value-for-money compared to using a dedicated link, but he has
 no guarantee that his end-users' usage won't get swamped by the use
 of other (perhaps much larger) partners on the shared link.  This
 could be seen as wishing to have a guaranteed minimum share according
 to some parameter(s).
 (c) On a shared link as under (b), the Network Manager may wish to
 ensure that usage of the link (which might be a high-performance
 trunk line on a network or an international link for example) by any
 one partner is "reasonable" in relation perhaps to his contribution
 to the costs.  In contrast to (b), the Network Manager is wishing to
 impose a maximum value on some parameter(s).  He may be happy if the
 width of the IT Service Manager's access link is not greater than his
 share of the shared link (assuming the measure agreed on is "width"),
 but this will commonly not be the case.  To be able to reach
 agreement, the Network Manager and the IT Service Manager may need
 options on the choice of parameters, and perhaps a choice on the
 means of control, as well as being able to negotiate about values.
 In circumstances where the Network Manager can exercise such controls
 over his customers, the IT Service Managers may say with some feeling
 and perhaps with justification, that if they are going to be
 controlled can the Network Manager please provide tools whereby they
 can arrange for the onward sharing of the resource they have, and
 thence onwards down the hierarchy to the end-users.

Jones [Page 2] RFC 1346 Resource Allocation, Control, and Accounting June 1992

 (d) It may be Network Manager A has a link that Network Manager B
 would like to use on occasion, perhaps as back-up on access to a
 third network.  Network Manager A might well wish to be
 accommodating, perhaps as examples because of financial benefit or
 perhaps because of the possibility of a reciprocal arrangement.
 However, the fear of overload affecting normal use and the lack of
 control over the usage militates against arrangements that the
 parties could be quite keen to make.
 Such challenges are very far from being unique to networking.
 Government and both public and private organisations and companies
 allocate budgets (and resources other than money), control and
 account for usage, recognising the possibility of overdrawing and
 borrowing.  In times of shortage, food is rationed.  I haven't
 checked this out, but it would surprise me if Jerry Hall wasn't
 guaranteed a ticket for any Rolling Stones concert, should she wish
 to attend.
 The charging factor influences use but does not control it (except
 perhaps in unusual circumstances where say payment was expected in
 advance and usage was cut off when the money ran out).
 In the IT world, multi-user hosts have filestore control systems; one
 that I use has an overdraft facility with no penalty for not having a
 prior arrangement!  There are also system designs and implementations
 for sharing host processor time with more sophistication than just
 counting seconds and chopping people off; this problem seems to me to
 be reasonably well understood.  (Library catalogue searches under
 author "John Larmouth" should provide some references for those who
 require convincing.)  Some multi-user hosts have controls of sorts on
 terminal connections.  On the other hand, I am not aware of any
 control system in operation that can guarantee multi-user host
 response time even outside the network context among directly
 connected terminals.
 The various roles bring different interests to bear.  A provider will
 not necessarily see it in his interests to control usage, or (perhaps
 even more likely) to provide customers with control tools, since the
 lack of these may encourage - or even oblige - the customer to buy
 more.  Even if the IT Service Manager can deal with the issue of who
 or what is important, and the issues of the relative importance of
 allocating resources against requests, other issues like social
 acceptability may arise to complicate his life.  For example it may
 be generally agreed (and perhaps the network manager instructed) that
 "everyone" must be able to do a small amount of work at any time,
 perhaps to do some housekeeping or seek information.

Jones [Page 3] RFC 1346 Resource Allocation, Control, and Accounting June 1992

 Time is an important factor.  Network resources, like computer
 processor time and unlike filestore, vanish if they are not used.
 People will in general prefer resources during prime shift to those
 in the middle of their night; however, in global terms the middle of
 their night can be during prime shift somewhere along their path of
 usage.
 What's to do?  Splitting lines with multiplexers is rather
 inflexible, and may well militate against the benefits of resource-
 sharing that give rise commonly to link-sharing arrangements.  Some
 technologies:
  1. have the ability to treat (or at least mark) traffic as of high

priority, for example where it gives emergency or status

      information;
  1. (in the case of X.25(84), I understand from my JNT colleague Ian

Smith,) have throughput class (section 6.13) and transit delay

      (section 6.27).  (Ian tells me that it is in his view far from
      clear how practical these facilities are);
  1. may be able to discriminate between traffic on grounds of

network source address;

  1. may be able to discriminate between traffic on grounds of

network destination address;

  1. may be able to discriminate between traffic on grounds of

application protocol, perhaps giving preference to interactive

      terminal traffic, or making a choice between preference for
      email and for file transfer traffic;
  1. may be able to discriminate between traffic on grounds of other

facets of network protocol or traffic.

 In practice, one may well not have adequate tools in these or other
 terms, and one may well have to ignore the challenges of resource
 control, and either ignore the issue or refuse service.

2. CONCLUSIONS

    2.1 There seems to be a lack of tools to enable the controlling
    and the sharing of networks and links.  This is militating against
    the cooperative sharing of resources, and restricting the ability
    of organisations to do business with one another.
    2.2 Further, the definition of what constitutes a share, or what
    parameter of service one would try to measure and control (or what

Jones [Page 4] RFC 1346 Resource Allocation, Control, and Accounting June 1992

    the choices are if any), is not clear.
    2.3 Following from that, it is then not clear whether what is
    needed is new or enhanced protocols/services, new or enhanced
    procurement specifications or profiles, or new or enhanced
    networking products or tools.
    2.4 Service providers (more likely the public carriers or but also
    some Network Managers) may see it as against their interests to
    provide controlling tools if they see them as tending to constrain
    usage and hence reducing income.  If so, they may not support, and
    may even oppose, progress in the area.  However, they might be
    persuaded that the provision of such tools might give them
    competitive edge over their rivals, and therefore to support
    appropriate projects and developments.

3. RECOMMENDATIONS

 There seems scope for one or more studies to:
  1. restate and refine the definition of the problems;
  1. collect, catalogue and relate relevant experience in both the

networking and non-networking fields;

  1. make recommendations as to what areas (e.g., among those

suggested in 2.3 above) projects should be undertaken;

  1. outline possible projects, indicating the timescale on which

improved sharing of production network service resources is

      likely to be achieved, and recommending an order of priority
      among the suggested projects.

FOOTNOTES:

 Gender issues - where appropriate, the male embraces the female and
 vice versa.
 Dramatis Personae:
    Jerry Hall is a close associate of Mr. M. Jagger, formerly of the
    London School of Economics in the University of London, and now
    Chairman and Chief Executive of an internationally prominent and
    successful commercial musical operation.
    Others mentioned in this paper are assumed to prefer to remain
    anonymous, although the standard is to give contact information
    for the author (see Author's Address section).

Jones [Page 5] RFC 1346 Resource Allocation, Control, and Accounting June 1992

Security Considerations

 Security issues are not discussed in this memo.

Author's Address

 Phil Jones
 JNT
 RAL, Chilton, Didcot, OXON  OX11 0QX
 Voice: +44-235-446618
 Fax:   +44-235-446251
 Email: p.jones@jnt.ac.uk  or c=gb;a= ;p=uk.ac;o=jnt;i=p;s=jones;

Jones [Page 6]

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