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Network Working Group                                           P. JonesRequest for Comments: 1346                        Joint Network Team, UK                                                               June 1992Resource Allocation, Control, and Accountingfor the Use of Network ResourcesStatus 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. Recommendations1. 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:      - have the ability to treat (or at least mark) traffic as of high        priority, for example where it gives emergency or status        information;      - (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);      - may be able to discriminate between traffic on grounds of        network source address;      - may be able to discriminate between traffic on grounds of        network destination address;      - 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;      - 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 whatJones                                                           [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:      - restate and refine the definition of the problems;      - collect, catalogue and relate relevant experience in both the        networking and non-networking fields;      - make recommendations as to what areas (e.g., among those        suggested in 2.3 above) projects should be undertaken;      - 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 1992Security 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]