- INTRODUCTION
-
- ------------
-
This note is a statement of our views on service cen- ter
- standards. It is an input to the service center panel discussion of
-
- the October Network meeting. Some areas are identified for
-
- consideration in intra-network standardiza- tion. We do not describe
-
- a methodology for analyzing com- puter systems; however, such analysis
-
- may be appropriate for solving the problems. We also do not enumerate
-
- the spectrum of services that may be required. We merely enu- merate
-
- areas where commonality of appearance and function can be of immediate
-
- value to a network user.
-
- CAVEAT
-
- ------
-
It is assumed that service centers will conform to official
- network standard protocols. This is essential for service centers
-
- since the effects of their practices are generally more wide-spread
-
- and are crucial to the effectiveness of minimal hosts such as TIPs.
-
- JUSTIFICATION
-
- -------------
-
The generation of network standards for service centers is of
- value to a very important class of people--the ultimate user
-
- community. We have such a community at Rand that is composed of
-
- research scientists and their support programmers. Certainly such
-
- users exist elsewhere, and a goal of the net- work must be to
-
- encourage their use. In the past, these researchers have relied
-
- solely on programmers to buffer them from computer detail.
-
- Standardization of services is cer- tainly a great value in expanding
-
- the community of users and eliminating the buffer.
-
Additionally, standards will be of benefit to those persons
- responsible for implementation of resource access programs. Instances
-
- and areas of standardization are cited below to support both of these
-
- statements.
-
[Page 1]
-
- -------------------------
-
Each host installation has its own standards for pro- gramming
- and operational procedures. From a network point of view, we are only
-
- interested in standards affecting external performance--primarily
-
- required operations and documentation of procedures. Intra-network
-
- standards should allow a user to plan his network use effectively to
-
- improve the performance of his tasks and take advantage of savings in
-
- both time and money.
-
- Remote Job Entry
-
- ----------------
-
One immediately apparent area for standardization is in the
- access to network resources. For example, there are two remote job
-
- entry (RJE) facilities on the network at present with two different
-
- data protocols. The UCSB facility was developed early to provide
-
- timely access to their resources. The UCLA facility was developed
-
- after the Telnet and Data Transfer protocols and takes advantage of
-
- them. If these two services appeared alike to the user and to the
-
- using process, two significant advantages would be obtained. First,
-
- the using system would need only one module to access both facilities.
-
- And secondly, a user could select either facility on a dynamic basis
-
- using the conditions influencing him at any given moment without any
-
- additional knowledge of the specific site.
-
- Login Procedures and Subsystem Access
-
- -------------------------------------
-
A more global example of common access to resources is the login
- procedure to remote systems. All systems require basically the same
-
- information--password, identification, account number. Yet the
-
- formats are syntactically inconsis- tent. An extension to the logger
-
- generally exists at these sites in the form of a "line scanner" for
-
- the network. In general, this module also performs other
-
- transformational functions. It would certainly be reasonable for this
-
- module to translate a network standard login into whatever format was
-
- required at the site. Perhaps to a lesser extent, a similar approach
-
- could be taken to constructing a uniform access to subsystems from the
-
- supervisor. In like fashion, a network standard interrupt could be
-
- translated into the escape (e.g., control C) of the serving host to
-
- return from a subsystem.
-
- Charging Algorithms and Accounting Protocol
-
- -------------------------------------------
-
To accurately forecast costs, a normalized formula for machine
[Page 2]
-
- easily added at the subnet and/or NCP levels--the relevant information
-
- is the same for all nodes, thus the Net charges are readily determined
-
- by any node. More difficult is the prediction and comparison of host
-
- charges. Like the login procedure example, each host uses the same
-
- ingredients, namely storage, I/O, connect time, and CPU resources
-
- expended. Again, like the login procedure the information is handled
-
- slightly dif- ferently in each case such that estimations are
-
- difficult. For example, some charge algorithms represent I/O as
-
- counts of I/O transactions where others clock I/O time. Without
-
- significantly perturbing anyone's local accounting proce- dures, it is
-
- desirable to normalize the charge components as a step toward
-
- reasonable cost comparisons and forecast- ing.
-
- Off-Line Services
-
- ----------------- .
-
Procedures need to be established for off-line services where
- they are offered as a service or are an integral part of a service.
-
- Such services are graphic hardcopy, large quantities of printer
-
- output, tape or disc facilities, etc. How are such items transmitted?
-
- What guarantees or state- ments should be made about turnaround times?
-
- How should they be specified--in terms of invocation and communication
-
- with operations staffs?
-
- Job Scheduling, Priorities and Status Information
-
- -------------------------------------------------
-
Extrapolating from the above rather static cost com- parisons
- that a normalized formula allows, envision a small but useful process,
-
- i.e., a throughput query service, that allows the user to dynamically
-
- determine the most cost ef- fective location for a job. (Such a
-
- service is technically reasonable since some systems now offer status
-
- data such as a core map and job queues display.) Imagine the user's
-
- situation. "Let's see, I need these numbers by 4:00 and I'm willing
-
- to pay a slight dollar premium to get them; the job will run on any
-
- Tenex machine, where should I run it?" The user would like to query
-
- Tenex systems, providing as input the requirements of his program, and
-
- get answers like probable turn-around time and cost vectors for dif-
-
- ferent priorities. (Incidentally, our non-programmer users are
-
- familiar with their job parameters (time, core space, etc.) since this
-
- information is normally part of the out- put stream.)
-
Most of the necessary elements for such a service are readily
- available in systems with which we are concerned. The query service
-
- would be a utility for users. This is the kind of a problem we should
-
- address concerning services vis-a-vis exporting Network concepts.
-
[Page 3]
-
- -----------
-
In addition to the above items, the user community could
- immediately benefit from standards in: documentation formats and
-
- distribution, operating schedules, the extent and availability of
-
- consulting services, data transmission and storage facilities,
-
- techniques for communication with operations staffs, and abnormal
-
- procedures such as system or program failures.
-
Some of the above items should be described in a standard format
- rather than the services themselves being standardized across the
-
- network. For example, schedules obviously vary in different time
-
- zones and each system has a different magnitude and policy for on-line
-
- storage capabilities.
-
To some extent these items are covered in the Resource Notebook.
- It should either be expanded to become a service center standards
-
- notebook or a separate item to fulfill that function should be
-
- created. For example, a site might have resources that it wished to
-
- offer on a limited or special arrangement basis to the network
-
- community and should be included as such in the Resource Notebook.
-
- However, that site might not wish to or have the staff to conform to
-
- network service center standards. Hence, the service center notebook
-
- would describe standards for a much more rigor- ously conforming
-
- community.
-
- SUMMARY
-
- -------
-
The theme of this note is that without classifying ser- vices and
- analyzing operations at service nodes, there are a number of areas
-
- that can be standardized to some extent throughout the network. What
-
- is needed is a manual of service center standards and a collection of
-
- documentation on services. Perhaps the latter is the Resource
-
- Notebook.
-
Service centers who intend to attract a significant network user
- community should be prepared to adopt a psychol- ogy appropriate to
-
- the market-oriented requirements for providing service. In the
-
- network at large, with our re- search orientation, personnel tend to
-
- have a different approach to computing than that required by a service
-
- bureau.
-
[ This RFC was put into machine readable form for entry ]
[ into the online RFC archives by BBN Corp. under the ]
[ direction of Alex McKenzie. 12/96 ]
[Page 4]
-