Network Working Group                                    Barry M. Leiner
Request for Comments: 1017                                         RIACS
                                                             August 1987

              Network Requirements for Scientific Research

              Internet Task Force on Scientific Computing

STATUS OF THIS MEMO

   This RFC identifies the requirements on communication networks for
   supporting scientific research.  It proposes some specific areas for
   near term work, as well as some long term goals.  This is an "idea"
   paper and discussion is strongly encouraged.  Distribution of this
   memo is unlimited.

INTRODUCTION

   Computer networks are critical to scientific research.  They are
   currently being used by portions of the scientific community to
   support access to remote resources (such as supercomputers and data
   at collaborator's sites) and collaborative work through such
   facilities as electronic mail and shared databases.  There is
   considerable movement in the direction of providing these
   capabilities to the broad scientific community in a unified manner,
   as evidence by this workshop. In the future, these capabilities will
   even be required in space, as the Space Station becomes a reality as
   a scientific research resource.

   The purpose of this paper is to identify the range of requirements
   for networks that are to support scientific research.  These
   requirements include the basic connectivity provided by the links and
   switches of the network through the basic network functions to the
   user services that need to be provided to allow effective use of the
   interconnected network.  The paper has four sections.  The first
   section discusses the functions a user requires of a network.  The
   second section discusses the requirements for the underlying link and
   node infrastructure while the third proposes a set of specifications
   to achieve the functions on an end-to-end basis.  The fourth section
   discusses a number of network-oriented user services that are needed
   in addition to the network itself.  In each section, the discussion
   is broken into two categories.  The first addresses near term
   requirements: those capabilities and functions that are needed today
   and for which technology is available to perform the function.  The
   second category concerns long term goals: those capabilities for
   which additional research is needed.

   This RFC was produced by the IAB Task force a Scientific Computing,

   which is chartered to investigate advanced networking requirements
   that result from scientific applications.  Work reported herein was
   supported in part by Cooperative Agreement NCC 2-387 from the
   National Aeronautics and Space Administration (NASA) to the
   Universities Space Research Association (USRA).

1.  NETWORK FUNCTIONS

   This section addresses the functions and capabilities that networks
   and particularly internetworks should be expected to support in the
   near term future.

Near Term Requirements

   There are many functions that are currently available to subsets of
   the user community.  These functions should be made available to the
   broad scientific community.

User/Resource Connectivity

   Undoubtedly the first order of business in networking is to provide
   interconnectivity of users and the resources they need.  The goal in
   the near term for internetworking should be to extend the
   connectivity as widely as possible, i.e. to provide ubiquitous
   connectivity among users and between users and resources.  Note that
   the existence of a network path between sites does not necessarily
   imply interoperability between communities and or resources using
   non-compatible protocol suites.  However, a minimal set of functions
   should be provided across the entire user community, independent of
   the protocol suite being used.  These typically include electronic
   mail at a minimum, file transfer and remote login capabilities must
   also be provided.

Home Usage

   One condition that could enhance current scientific computing would
   be to extend to the home the same level of network support that the
   scientist has available in his office environment.  As network access
   becomes increasingly widespread, the extension to the home will allow
   the user to continue his computing at home without dramatic changes
   in his work habits, based on limited access.

Charging

   The scientific user should not have to worry about the costs of data
   communications any more than he worries about voice communications
   (his office telephone), so that data communications becomes an
   integral and low-cost part of our national infrastructure.  This

   implies that charges for network services must NOT be volume
   sensitive and must NOT be charged back to the individual.  Either of
   these conditions forces the user to consider network resources as
   scarce and therefore requiring his individual attention to conserve
   them.  Such attention to extraneous details not only detracts from
   the research, but fundamentally impacts the use and benefit that
   networking is intended to supply.  This does not require that
   networking usage is free.  It should be either be low enough cost
   that the individual does not have to be accountable for "normal"
   usage or managed in such a manner that the individual does not have
   to be concerned with it on a daily basis.

Applications

   Most applications, in the near term, which must be supported in an
   internetwork environment are essentially extensions of current ones.
   Particularly:

      Electronic Mail

         Electronic mail will increase in value as the extended
         interconnectivity provided by internetworking provides a much
         greater reachability of users.

      Multimedia Mail

         An enhancement to text based mail which includes capabilities
         such as figures, diagrams, graphs, and digitized voice.

      Multimedia Conferencing

         Network conferencing is communication among multiple people
         simultaneously.  Conferencing may or may not be done in "real
         time", that is all participants may not be required to be on-
         line at the same time.  The multimedia supported may include
         text, voice, video, graphics, and possibly other capabilities.

      File Transfer

         The ability to transfer data files.

      Bulk Transfer

         The ability to stream large quantities of data.

      Interactive Remote Login

         The ability to perform remote terminal connections to hosts.

      Remote Job Entry

         The ability to submit batch jobs for processing to remote hosts
         and receive output.

         Applications which need support in the near term but are NOT
         extensions of currently supported applications include:

      Remote Instrument Control

         This normally presumes to have a human in the "control loop".
         This condition relaxes the requirements on the (inter)network
         somewhat as to response times and reliability.  Timing would be
         presumed to be commensurate with human reactions and
         reliability would not be as stringent as that required for
         completely automatic control.

      Remote Data Acquisition

         This supports the collection of experimental data where the
         experiment is remotely located from the collection center.
         This requirement can only be satisfied when the bandwidth,
         reliability, and predictability of network response are
         sufficient.  This cannot be supported in the general sense
         because of the enormous bandwidth, very high reliability,
         and/or guaranteed short response time required for many
         experiments.

   These last two requirements are especially crucial when one considers
   remote experimentation such as will be performed on the Space
   Station.

Capabilities

   The above applications could be best supported on a network with
   infinite bandwidth, zero delay, and perfect reliability.
   Unfortunately, even currently feasible approximations to these levels
   of capabilities can be very expensive. Therefore, it can be expected
   that compromises will be made for each capability and between them,
   with different balances struck between different networks.  Because
   of this, the user must be given an opportunity to declare which
   capability or capabilities is/are of most interest-most likely
   through a "type-of-service" required declaration.  Some examples of
   possible trade-offs: File Transport Normally requires high
   reliability primarily and high bandwidth secondarily. Delay is not as
   important.

      Bulk Transport

         Some applications such as digitized video might require high
         bandwidth as the most important capability.  Depending on the
         application, delay would be second, and reliability of lesser
         importance.  Image transfers of scientific data sometimes will
         invert the latter two requirements.

      Interactive Traffic

         This normally requires low delay as a primary consideration.
         Reliability may be secondary depending on the application.
         Bandwidth would usually be of least importance.

Standards

    The use of standards in networking is directed toward
    interoperability and availability of commercial equipment.  However,
    as stated earlier, full interoperability across the entire
    scientific community is probably not a reasonable goal for
    internetworking in the near term because of the protocol mix now
    present.  That is not to say, though, that the use of standards
    should not be pursued on the path to full user interoperability.
    Standards, in the context of near term goal support, include:

Media Exchange Standards

   Would allow the interchange of equations, graphics, images, and data
   bases as well as text.

Commercially Available Standards

   Plug compatible, commercially available standards will allow a degree
   of interoperability prior to the widespread availability of the ISO
   standard protocols.

Long Term Goals

   In the future, the internetwork should be transparent communications
   between users and resources, and provide the additional network
   services required to make use of that communications.  A user should
   be able to access whatever resources are available just as if the
   resource is in the office.  The same high level of service should
   exist independent of which network one happens to be on.  In fact,
   one should not even be able to tell that the network is there!

   It is also important that people be able to work effectively while at
   home or when traveling.  Wherever one may happen to be, it should be

   possible to "plug into" the internetwork and read mail, access files,
   control remote instruments, and have the same kind of environment one
   is used to at the office.

   Services to locate required facilities and take advantage of them
   must also be available on the network.  These range from the basic
   "white" and "yellow" pages, providing network locations (addresses)
   for users and capabilities, through to distributed data bases and
   computing facilities.  Eventually, this conglomeration of computers,
   workstations, networks, and other computing resources will become one
   gigantic distributed "world computer" with a very large number of
   processing nodes all over the world.

2.  NETWORK CONNECTIVITY

   By network connectivity, we mean the ability to move packets from one
   point to another.

   Note that an implicit assumption in this paper is that packet
   switched networks are the preferred technology for providing a
   scientific computer network.  This is due to the ability of such
   networks to share the available link resources to provide
   interconnection between numerous sites and their ability to
   effectively handle the "bursty" computer communication requirement.

   Note that this need not mean functional interoperability, since the
   endpoints may be using incompatible protocols.  Thus, in this
   section, we will be addressing the use of shared links and
   interconnected networks to provide a possible path.  In the next
   section, the exploitation of these paths to achieve functional
   connectivity will be addressed.

   In this section, we discuss the need for providing these network
   paths to a wide set of users and resources, and the characteristics
   of those paths.  As in other sections, this discussion is broken into
   two major categories.  The first category are those goals which we
   believe to be achievable with currently available technology and
   implementations.  The second category are those for which further
   research is required.

Near Term Objectives

   Currently, there are a large number of networks serving the
   scientific community, including Arpanet, MFEnet, SPAN, NASnet, and
   the NSFnet backbone.  While there is some loose correlation between
   the networks and the disciplines they serve, these networks are
   organized more based on Federal funding.  Furthermore, while there is
   significant interconnectivity between a number of the networks, there

   is considerable room for more sharing of these resources.

   In the near term, therefore, there are two major requirement areas;
   providing for connectivity based on discipline and user community,
   and providing for the effective use of adequate networking resources.

Discipline Connectivity

   Scientists in a particular community/discipline need to have access
   to many common resources as well as communicate with each other.  For
   example, the quantum physics research community obtains funding from
   a number of Federal sources, but carries out its research within the
   context of a scientific discourse.  Furthermore, this discourse often
   overlaps several disciplines.  Because networks are generally
   oriented based on the source of funding, this required connectivity
   has in the past been inhibited.  NSFnet is a major step towards
   satisfying this requirement, because of its underlying philosophy of
   acting as an interconnectivity network between supercomputer centers
   and between state, regional, and therefore campus networks.  This
   move towards a set of networks that are interconnected, at least at
   the packet transport level, must be continued so that a scientist can
   obtain connectivity between his/her local computing equipment and the
   computing and other resources that are needed, independently of the
   source of funds.

   Obviously, actual use of those resources will depend on obtaining
   access permission from the appropriate controlling organization.  For
   example, use of a supercomputer will require permission and some
   allocation of computing resources.  The lack of network access should
   not, however, be the limiting factor for resource utilization.

Communication Resource Sharing

   The scientific community is always going to suffer from a lack of
   adequate communication bandwidth and connections.  There are
   requirements (e.g. graphic animation from supercomputers) that
   stretch the capabilities of even the most advanced long-haul
   networks.  In addition, as more and more scientists require
   connection into networks, the ability to provide those connections on
   a network-centric basis will become more and more difficult.

   However, the communication links (e.g. leased lines and satellite
   channels) providing the underlying topology of the various networks
   span in aggregate a very broad range of the scientific community
   sites.  If, therefore, the networks could share these links in an
   effective manner, two objectives could be achieved:

      The need to add links just to support a particular network

      topology change would be decreased, and

      New user sites could be connected more readily.

   Existing technology (namely the DARPA-developed gateway system based
   on the Internet Protocol, IP) provides an effective method for
   accomplishing this sharing.  By using IP gateways to connect the
   various networks, and by arranging for suitable cost-sharing, the
   underlying connectivity would be greatly expanded and both of the
   above objectives achieved.

Expansion of Physical Structure

   Unfortunately, the mere interconnectivity of the various networks
   does not increase the bandwidth available.  While it may allow for
   more effective use of that available bandwidth, a sufficient number
   of links with adequate bandwidth must be provided to avoid network
   congestion.  This problem has already occurred in the Arpanet, where
   the expansion of the use of the network without a concurrent
   expansion in the trunking and topology has resulted in congestion and
   consequent degradation in performance.

   Thus, it is necessary to augment the current physical structure
   (links and switches) both by increasing the bandwidth of the current
   configuration and by adding additional links and switches where
   appropriate.

Network Engineering

   One of the major deficiencies in the current system of networks is
   the lack of overall engineering.  While each of the various networks
   generally is well supported, there is woefully little engineering of
   the overall system.  As the networks are interconnected into a larger
   system, this need will become more severe.  Examples of the areas
   where engineering is needed are:

   Topology engineering-deciding where links and switches should be
   installed or upgraded.  If the interconnection of the networks is
   achieved, this will often involve a decision as to which networks
   need to be upgraded as well as deciding where in the network those
   upgrades should take place.

   Connection Engineering-when a user site desires to be connected,
   deciding which node of which network is the best for that site,
   considering such issues as existing node locations, available
   bandwidth, and expected traffic patterns to/from that site.

   Operations and Maintenance-monitoring the operation of the overall

   system and identifying corrective actions when failures occur.

Support of Different Types of Service

   Several different end user applications are currently in place, and
   these put different demands on the underlying structure.  For
   example, interactive remote login requires low delay, while file
   transfer requires high bandwidth.  It is important in the
   installation of additional links and switches that care be given to
   providing a mix of link characteristics.  For example, high bandwidth
   satellite channels may be appropriate to support broadcast
   applications or graphics, while low delay will be required to support
   interactive applications.

Future Goals

   Significant expansion of the underlying transport mechanisms will be
   required to support future scientific networking.  These expansions
   will be both in size and performance.

Bandwidth

   Bandwidth requirements are being driven higher by advances in
   computer technology as well as the proliferation of that technology.
   As high performance graphics workstations work cooperatively with
   supercomputers, and as real-time remote robotics and experimental
   control become a reality, the bandwidth requirements will continue to
   grow.  In addition, as the number of sites on the networks increase,
   so will the aggregate bandwidth requirement.  However, at the same
   time, the underlying bandwidth capabilities are also increasing.
   Satellite bandwidths of tens of megabits are available, and fiber
   optics technologies are providing extremely high bandwidths (in the
   range of gigabits).  It is therefore essential that the underlying
   connectivity take advantage of these advances in communications to
   increase the available end-to-end bandwidth.

Expressway Routing

   As higher levels of internet connectivity occur there will be a new
   set of problems related to lowest hop count and lowest delay routing
   metrics. The assumed internet connectivity can easily present
   situations where the highest speed, lowest delay route between two
   nodes on the same net is via a route on another network.  Consider
   two sites one either end of the country, but both on the same
   multipoint internet, where their network also is gatewayed to some
   other network with high speed transcontinental links.  The routing
   algorithms must be able to handle these situations gracefully, and
   they become of increased importance in handling global type-of-

   service routing.

3.  NETWORK SPECIFICATIONS

    To achieve the end-to-end user functions discussed in section 2, it
    is not adequate to simply provide the underlying connectivity
    described in the previous section.  The network must provide a
    certain set of capabilities on an end-to-end basis.  In this
    section, we discuss the specifications on the network that are
    required.

Near Term Specifications

   In the near term, the requirements on the networks are two-fold.
   First is to provide those functions that will permit full
   interoperability, and second the internetwork must address the
   additional requirements that arise in the connection of networks,
   users, and resources.

Interoperability

   A first-order requirement for scientific computer networks (and
   computer networks in general) is that they be interoperable with each
   other, as discussed in the above section on connectivity.  A first
   step to accomplish this is to use IP.  The use of IP will allow
   individual networks built by differing agencies to combine resources
   and minimize cost by avoiding the needless duplication of network
   resources and their management.  However, use of IP does not provide
   end-to-end interoperability.  There must also be compatibility of
   higher level functions and protocols.  At a minimum, while commonly
   agreed upon standards (such as the ISO developments) are proceeding,
   methods for interoperability between different protocol suites must
   be developed.  This would provide interoperability of certain
   functions, such as file transfer, electronic mail and remote login.
   The emphasis, however, should be on developing agreement within the
   scientific community on use of a standard set of protocols.

Access Control

   The design of the network should include adequate methods for
   controlling access to the network by unauthorized personnel.  This
   especially includes access to network capabilities that are reachable
   via the commercial phone network and public data nets.  For example,
   terminal servers that allow users to dial up via commercial phone
   lines should have adequate authentication mechanisms in place to
   prevent access by unauthorized individuals.  However, it should be
   noted that most hosts that are reachable via such networks are also
   reachable via other "non-network" means, such as directly dialing

   over commercial phone lines.  The purpose of network access control
   is not to insure isolation of hosts from unauthorized users, and
   hosts should not expect the network itself to protect them from
   "hackers".

Privacy

   The network should provide protection of data that traverses it in a
   way that is commensurate with the sensitivity of that data.  It is
   judged that the scientific requirements for privacy of data traveling
   on networks does not warrant a large expenditure of resources in this
   area.  However, nothing in the network design should preclude the use
   of link level or end-to-end encryption, or other such methods that
   can be added at a later time.  An example of this kind of capability
   would be use of KG-84A link encryptors on MILNET or the Fig Leaf
   DES-based end-to-end encryption box developed by DARPA.

Accounting

   The network should provide adequate accounting procedures to track
   the consumption of network resources.  Accounting of network
   resources is also important for the management of the network, and
   particularly the management of interconnections with other networks.
   Proper use of the accounting database should allow network management
   personnel to determine the "flows" of data on the network, and the
   identification of bottlenecks in network resources.  This capability
   also has secondary value in tracking down intrusions of the network,
   and to provide an audit trail if malicious abuse should occur.  In
   addition, accounting of higher level network services (such as
   terminal serving) should be kept track of for the same reasons.

Type of Service Routing

   Type of service routing is necessary since not all elements of
   network activity require the same resources, and the opportunities
   for minimizing use of costly network resources are large.  For
   example, interactive traffic such as remote login requires low delay
   so the network will not be a bottleneck to the user attempting to do
   work.  Yet the bandwidth of interactive traffic can be quite small
   compared to the requirements for file transfer and mail service which
   are not response time critical.  Without type of service routing,
   network resources must sized according to the largest user, and have
   characteristics that are pleasing to the most finicky user.  This has
   major cost implications for the network design, as high-delay links,
   such as satellite links, cannot be used for interactive traffic
   despite the significant cost savings they represent over terrestrial
   links.  With type of service routing in place in the network
   gateways, and proper software in the hosts to make use of such

   capabilities, overall network performance can be enhanced, and
   sizable cost savings realized.  Since the IP protocol already has
   provisions for such routing, such changes to existing implementations
   does not require a major change in the underlying protocol
   implementations.

Administration of Address Space

   Local administration of network address space is essential to provide
   for prompt addition of hosts to the network, and to minimize the load
   on backbone network administrators.  Further, a distributed name to
   address translation service also has similar advantages.  The DARPA
   Name Domain system currently in use on the Internet is a suitable
   implementation of such a name to address translation system.

Remote Procedure Call Libraries

   In order to provide a standard library interface so that distributed
   network utilities can easily communicate with each other in a
   standard way, a standard Remote Procedure Call (RPC) library must be
   deployed.  The computer industry has lead the research community in
   developing RPC implementations, and current implementations tend to
   be compatible within the same type of operating system, but not
   across operating systems.  Nonetheless, a portable RPC implementation
   that can be standardized can provide a substantial boost in present
   capability to write operating system independent network utilities.
   If a new RPC mechanism is to be designed from scratch, then it must
   have enough capabilities to lure implementors away from current
   standards.  Otherwise, modification of an existing standard that is
   close to the mark in capabilities seems to be in order, with the
   cooperation of vendors in the field to assure implementations will
   exist for all major operating systems in use on the network.

Remote Job Entry (RJE)

   The capabilities of standard network RJE implementations are
   inadequate, and are implemented prolifically among major operating
   systems.  While the notion of RJE evokes memories of dated
   technologies such as punch cards, the concept is still valid, and is
   favored as a means of interaction with supercomputers by science
   users.  All major supercomputer manufacturers support RJE access in
   their operating systems, but many do not generalize well into the
   Internet domain.  That is, a RJE standard that is designed for 2400
   baud modem access from a card reader may not be easily modifiable for
   use on the Internet.  Nonetheless, the capability for a network user
   to submit a job from a host and have its output delivered on a
   printer attached to a different host would be welcomed by most
   science users.  Further, having this capability interoperate with

   existing RJE packages would add a large amount of flexibility to the
   whole system.

Multiple Virtual Connections

   The capability to have multiple network connections open from a
   user's workstation to remote network hosts is an invaluable tool that
   greatly increases user productivity.  The network design should not
   place limits (procedural or otherwise) on this capability.

Network Operation and Management Tools

   The present state of internet technology requires the use of
   personnel who are, in the vernacular of the trade, called network
   "wizards," for the proper operation and management of networks.
   These people are a scarce resource to begin with, and squandering
   them on day to day operational issues detracts from progress in the
   more developmental areas of networking.  The cause of this problem is
   that a good part of the knowledge for operating and managing a
   network has never been written down in any sort of concise fashion,
   and the reason for that is because networks of this type in the past
   were primarily used as a research tool, not as an operational
   resource.  While the usage of these networks has changed, the
   technology has not adjusted to the new reality that a wizard may not
   be nearby when a problem arises.  To insure that the network can
   flexibly expand in the future, new tools must be developed that allow
   non-wizards to monitor network performance, determine trouble spots,
   and implement repairs or 'work-arounds'.

Future Goals

   The networks of the future must be able to support transparent access
   to distributed resources of a variety of different kinds.  These
   resources will include supercomputer facilities, remote observing
   facilities, distributed archives and databases, and other network
   services.  Access to these resources is to be made widely available
   to scientists, other researchers, and support personnel located at
   remote sites over a variety of internetted connections.  Different
   modes of access must be supported that are consonant with the sorts
   of resources that are being accessed, the data bandwidths required
   and the type of interaction demanded by the application.

   Network protocol enhancements will be required to support this
   expansion in functionality; mere increases in bandwidth are not
   sufficient.  The number of end nodes to be connected is in the
   hundreds of thousands, driven by increasing use of microprocessors
   and workstations throughout the community.  Fundamentally different
   sorts of services from those now offered are anticipated, and dynamic

   bandwidth selection and allocation will be required to support the
   different access modes.  Large-scale internet connections among
   several agency size internets will require new approaches to routing
   and naming paradigms.  All of this must be planned so as to
   facilitate transition to the ISO/OSI standards as these mature and
   robust implementations are placed in service and tuned for
   performance.

   Several specific areas are identified as being of critical importance
   in support of future network requirements, listed in no particular
   order:

      Standards and Interface Abstractions

         As more and different services are made available on these
         various networks it will become increasingly important to
         identify interface standards and suitable application
         abstractions to support remote resource access.  These
         abstractions may be applicable at several levels in the
         protocol hierarchy and can serve to enhance both applications
         functionality and portability.  Examples are transport or
         connection layer abstractions that support applications
         independence from lower level network realizations or interface
         abstractions that provide a data description language that can
         handle a full range of abstract data type definitions.
         Applications or connection level abstractions can provide means
         of bridging across different protocol suites as well as helping
         with protocol transition.

      OSI Transition and Enhancements

         Further evolution of the OSI network protocols and realization
         of large-scale networks so that some of the real protocol and
         tuning issues can be dealt with must be anticipated.  It is
         only when such networks have been created that these issues can
         be approached and resolved.  Type-of-service and Expressway
         routing and related routing issues must be resolved before a
         real transition can be contemplated.  Using the interface
         abstraction approach just described will allow definition now
         of applications that can transition as the lower layer networks
         are implemented.  Applications gateways and relay functions
         will be a part of this transition strategy, along with dual
         mode gateways and protocol translation layers.

      Processor Count Expansion

         Increases in the numbers of nodes and host sites and the
         expected growth in use of micro-computers, super-micro

         workstations, and other modest cost but high power computing
         solutions will drive the development of different network and
         interconnect strategies as well as the infrastructure for
         managing this increased name space.  Hierarchical name
         management (as in domain based naming) and suitable transport
         layer realizations will be required to build networks that are
         robust and functional in the face of the anticipated
         expansions.

      Dynamic Binding of Names to Addresses

         Increased processor counts and increased usage of portable
         units, mobile units and lap-top micros will make dynamic
         management of the name/address space a must.  Units must have
         fixed designations that can be re-bound to physical addresses
         as required or expedient.

4.  USER SERVICES

   The user services of the network are a key aspect of making the
   network directly useful to the scientist.  Without the right user
   services, network users separate into artificial subclasses based on
   their degree of sophistication in acquiring skill in the use of the
   network.  Flexible information dissemination equalizes the
   effectiveness of the network for different kinds of users.

Near Term Requirements

   In the near term, the focus is on providing the services that allow
   users to take advantage of the functions that the interconnected
   network provides.

Directory services

   Much of the information necessary in the use of the network is for
   directory purposes.  The user needs to access resources available on
   the network, and needs to obtain a name or address.

White Pages

   The network needs to provide mechanisms for looking up names and
   addresses of people and hosts on the network.  Flexible searches
   should be possible on multiple aspects of the directory listing.
   Some of these services are normally transparent to the user/host name
   to address translation for example.

Yellow Pages

   Other kinds of information lookup are based on cataloging and
   classification of information about resources on the networks.

Information Sharing Services

      Bulletin Boards

         The service of the electronic bulletin board is the one-to-many
         analog of the one-to-one service of electronic mail.  A
         bulletin board provides a forum for discussion and interchange
         of information.  Accessibility is network-wide depending on the
         definition of the particular bulletin board.  Currently the
         SMTP and UUCP protocols are used in the transport of postings
         for many bulletin boards, but any similar electronic mail
         transport can be substituted without affecting the underlying
         concept.  An effectively open-ended recipient list is specified
         as the recipient of a message, which then constitutes a
         bulletin board posting.  A convention exists as to what
         transport protocols are utilized for a particular set of
         bulletin boards.  The user agent used to access the Bulletin
         Board may vary from host to host.  Some number of host
         resources on the network provide the service of progressively
         expanding the symbolic mail address of the Bulletin Board into
         its constituent parts, as well as relaying postings as a
         service to the network.  Associated with this service is the
         maintenance of the lists used in distributing the postings.
         This maintenance includes responding to requests from Bulletin
         Board readers and host Bulletin Board managers, as well as
         drawing the appropriate conclusions from recurring
         automatically generated or error messages in response to
         distribution attempts.

      Community Archiving

         Much information can be shared over the network.  At some point
         each particular information item reaches the stage where it is
         no longer appropriately kept online and accessible.  When
         moving a file of information to offline storage, a network can
         provide its hosts a considerable economy if information of
         interest to several of them need only be stored offline once.
         Procedures then exist for querying and retrieving from the set
         of offline stored files.

      Shared/distributed file system

         It should be possible for a user on the network to look at a

         broadly defined collection of information on the network as one
         useful whole.  To this end, standards for accessing files
         remotely are necessary.  These standards should include means
         for random access to remote files, similar to the generally
         employed on a single computer system.

      Distributed Databases and Archives

         As more scientific disciplines computerize their data archives
         and catalogs, mechanisms will have to be provided to support
         distributed access to these resources.  Fundamentally new kins
         of collaborative research will become possible when such
         resources and access mechanisms are widely available.

      Resource Sharing Services

         In sharing the resources or services available on the network,
         certain ancillary services are needed depending on the
         resource.

Access Control

   Identification and authorization is needed for individuals, hosts or
   subnetworks permitted to make use of a resource available via the
   network.  There should be consistency of procedure for obtaining and
   utilizing permission for use of shared resources.  The identification
   scheme used for access to the network should be available for use by
   resources as well.  In some cases, this will serve as sufficient
   access control, and in other cases it will be a useful adjunct to
   resource-specific controls.  The information on the current network
   location of the user should be available along with information on
   user identification to permit added flexibility for resources.  For
   example, it should be possible to verify that an access attempt is
   coming from within a state.  A state agency might then grant public
   access to its services only for users within the state.  Attributes
   of individuals should be codifiable within the access control
   database, for example membership in a given professional society.

Privacy

   Users of a resource have a right to expect that they have control
   over the release of the information they generate.  Resources should
   allow classifying information according to degree of access, i.e.
   none, access to read, access according to criteria specified in the
   data itself, ability to change or add information.  The full range of
   identification information described under access control should be
   available to the user when specifying access.  Access could be
   granted to all fellow members of a professional society, for example.

Accounting

   To permit auditing of usage, accounting information should be
   provided for those resources for which it is deemed necessary.  This
   would include identity of the user of the resource and the
   corresponding volume of resource components.

Legalities of Interagency Research Internet

   To make the multiply-sponsored internetwork feasible, the federal
   budget will have to recognize that some usage outside a particular
   budget category may occur.  This will permit the cross-utilization of
   agency funded resources.  For example, NSFnet researchers would be
   able to access supercomputers over NASnet.  In return for this, the
   total cost to the government will be significantly reduced because of
   the benefits of sharing network and other resources, rather than
   duplicating them.

Standards

   In order for the networking needs of scientific computing to be met,
   new standards are going to evolve.  It is important that they be
   tested under actual use conditions, and that feedback be used to
   refine them.  Since the standards for scientific communication and
   networking are to be experimented with, they are more dynamic than
   those in other electronic communication fields.  It is critical that
   the resources of the network be expended to promulgate experimental
   standards and maximize the range of the community utilizing them.  To
   this end, the sharing of results of the testing is important.

User-oriented Documentation

   The functionality of the network should be available widely without
   the costly need to refer requests to experts for formulation.  A
   basic information facility in the network should therefore be
   developed.  The network should be self-documenting via online help
   files, interactive tutorials, and good design.  In addition, concise,
   well-indexed and complete printed documentation should be available.

Future Goals

   The goal for the future should be to provide the advanced user
   services that allow full advantage to be taken of the interconnection
   of users, computing resources, data bases, and experimental
   facilities.  One major goal would be the creation of a national
   knowledge bank.  Such a knowledge bank would capture and organize
   computer-based knowledge in various scientific fields that is
   currently available only in written/printed form, or in the minds of

   experts or experienced workers in the field.  This knowledge would be
   stored in knowledge banks which will be accessible over the network
   to individual researchers and their programs.  The result will be a
   codification of scientific understanding and technical know-how in a
   series of knowledge based systems which would become increasingly
   capable over time.

CONCLUSION

   In this paper, we have tried to describe the functions required of
   the interconnected national network to support scientific research.
   These functions range from basic connectivity through to the
   provision for powerful distributed user services.

   Many of the goals described in this paper are achievable with current
   technology.  They require coordination of the various networking
   activities, agreement to share costs and technologies, and agreement
   to use common protocols and standards in the provision of those
   functions.  Other goals require further research, where the
   coordination of the efforts and sharing of results will be key to
   making those results available to the scientific user.

   For these reasons, we welcome the initiative represented by this
   workshop to have the government agencies join forces in providing the
   best network facilities possible in support of scientific research.

APPENDIX

                Internet Task Force on Scientific Computing


             Rick Adrion     University of Massachusetts
             Ron Bailey      NASA Ames Research Center
             Rick Bogart     Stanford University
             Bob Brown       RIACS
             Dave Farber     University of Delaware
             Alan Katz       USC Information Science Institute
             Jim Leighton    Lawrence Livermore Laboratories
             Keith Lantz     Stanford University
             Barry Leiner    (chair) RIACS
             Milo Medin      NASA Ames Research Center
             Mike Muuss      US Army Ballistics Research Laboratory
             Harvey Newman   California Institute of Technology
             David Roode     Intellicorp
             Ari Ollikainen  General Electric
             Peter Shames    Space Telescope Science Institute
             Phil Scherrer   Stanford University