Produced by the Computer Board And Research Councils' Joint Network Team and Network Executive.
Dr Peter Linington has been appointed as the new head of the Joint Network Team and Network Executive. Peter gained his PhD while working at the Cavendish Laboratory and worked in the Computing Service at Cambridge from 1971 to 1982. He was seconded for 3 years during this period to the Data Communications Protocols Unit of the Department of Industry. In 1982 he joined the SERC as coordinator for the Universe project concerned with research into high speed communications using Cambridge Rings and a broadcast satellite network. Peter formally assumed his new post on 1 November.
Ian Smith has been appointed as Principle Scientific in the Network Executive. Ian has worked at Laboratory since 1966 and for the last 7 years in the field of network development and operations. Keith Mainwaring has also joined the Network Executive from the Rutherford Appleton Laboratory Network Operations Group, Ian and Keith have already started work both formally and in the sense that they were both members of the temporary executive.
Further positions in the JNT and Executive are as yet unfilled.
Networkshop 12 will be held on 16-18 April 1984 at the University of Bath. It is planned to adopt a similar style to the Networkshop at Royal Holloway College with the conference running from midday on the Monday to midday on Wednesday and with a session of parallel discussion groups. Unfortunately there is a limit on the number of participants that can be accommodated and the demand is likely to substantially exceed this figure. Invitations will be sent out early with a firm closing date of January 31st so that a fair level of representation from all institutions can be ensured. This will mean that it will not be possible to give a description of the programme in the invitation letter.
The University of York have been developing software to provide an X25 networking capability for ICL PERQ running PNX. The software is essentially the same as York are supplying for PDP11 and VAX UNIX except that the front end LSI-11 which handles the X25 and X29 protocols is connected to the host system via an asynchronous rather than a parallel link. The project is seen as a quick way of providing the PERQ with X25 and coloured book software. The cost of the hardware for the front end is about £2000 and the software is free to academic community customers.
The software is now on field test at Rutherford Appleton Laboratory and Queen Mary College, London. General release is expected to coincide with the next release of PNX from ICL. Further details may be obtained from Ken Robinson at RAL on 0235-446491 (SERC customers) or Carol Hirst at QMC on 01-980-4811 ext 3222 (Computer Board customers) or Steve Smith at York on 0904-59861 ext 5941.
The Executive has been given the task of replacing the present diverse wide-area arrangements in the Academic and Research Council community with a unified X25-based network. This is to be achieved by evolution, not revolution, using the existing SERC wide-area switches as a basis for expansion. Full responsibility for the operation of the network will be assumed by the Executive on 1 April 1984, but in the meantime we are working closely with the existing SERC management committees.
Let me make it clear from the outset that this is not simply a paper exercise shifting responsibility from SERC to the Computer Board. The Executive is committed to improving the network service (subject, of course, to whatever budgetary restraints are placed upon it) and already a programme of enhancements has been proposed to the Board for 1984/85. These are outlined below. It is our intention to keep the service under constant review, and to propose further enhancements as usage patterns dictate.
The SERCNET switches which the Executive will take over next year at present run software developed by the Rutherford Appleton Laboratory. It is planned to move to using software supplied by GEC by the end of financial year 1984/85, at the latest Additional switches at Belfast, SWURCC and UMRCC will run GEC software from the outset. A phased transition is planned on the SERCNET switches, involving at least one intermediate step and additional memory has already been purchased to allow this to proceed. In addition. 4000 Series machines will need to be upgraded to 4100 Series machines to support the new product lines that GEC are proposing. This implies a great deal of work over the next 18 months or so, but there is much to be gained as the GEC product will give us management capabilities which we do not have with the present SERC software and without which a high level of user service cannot be guaranteed.
Present connections are almost entirely based on Tariff T circuits utilising multiplexing modem with an overall maximum throughput of 9.6Kbps. British Telecom is now offering a digital service called Kilostream, which can be utilised at up to 48Kbps with our present GEC hardware, at prices which compare favourably with existing Tariff T costs. We have already ordered six 48Kbps lines, to interconnect the switches at UMRCC, ULCC, Daresbury and Rutherford Appleton Laboratories. Because Kilostream is not available immediately in all parts of the country, only the UMRCC-ULCC line can be installed now, but we anticipate that links to RAL will be available early in the new year, and we are pressing British Telecom to make provision for Daresbury as well in the near future. Further such enhancements are planned for 1984/85.
The JANET switches will be operated on behalf of the Executive by locally employed staff at the various Network Operations Centres (NOCs). Discussion involving all potential NOC sites are already underway, and sub-groups have been set up to discuss contracts for the NOCs and to define procedures for handling faults.
It is planned to have regional user meetings which will be attended by Executive members' and for representatives of the appropriate NOCs. These will provide users with a forum for airing their views, grievances etc, although I hope that they will be constructive rather than destructive. Representatives from these meetings will attend a National meeting whose Chairman will represent users' views on the Network Advisory Committee which the Computer Board has set up to overview the work of both the Executive and the JNT.
Finally, let me stress that the Executive is a service group. Its function is to provide the best possible service for its users, and to this end I appeal to you to let us know what you want and like as well as what you do not want and dislike. If we are to keep ahead of demand, we need to know well in advance what your needs are likely to be.
There is a high degree of interest in Ethernet networks and many sites within the Community are engaged in or planning some activity.
However, the situation with regard to protocols is rather confused and we have now had our second Ethernet liaison meeting to attempt to reach a level of consensus within the community.
As a result of the first meeting our brief was to study the IEEE 802 and Information Technology Standards Unit (ITSU) documents which, whilst helping to focus our attention on a smaller range of solutions, do not have absolute recommendations to make at all the protocol layers required to offer a network service.
At our second meeting the protocol discussions resulted in three main areas of interest.
Option 1: To follow the ECMA recommendations and implement CLASS 4 Transport protocol with an offered service equivalent to Yellow Book Transport Service (YBTS) so as to allow the current high-level protocols to be used. This proposal has the advantage that some implementations of the ECMA protocols already exist.
Option 2: To implement IEEE 802 logical Link Control type 2 procedures with a modified X25 Level 3 above and through this to YBTS. However a full set of recommendations for the X25 modifications do not exist and current implementations are not known.
The third area of interest was in a datagram service and this was agreed to be an additional requirement for the future and not an option to be considered against the other two.
The majority of the sites represented at the meeting were prepared to accept option 1 as a solution until the situation on international standards is much clearer, but one or two sites will implement option 2.
The meeting agreed that it was essential to monitor the progress of both implementations and that interested sites in each case would hold collaboration meetings and try to avoid duplication of valuable effort by sharing the work to be done where possible. John Thomas from SWURCC is to host the first meeting for those interested in option 1 and RAL have been invited to consider holding the meeting for option 2. Progress on datagram techniques will be monitored by the whole group.
At a lower level we agreed to adopt IEEE 8023 specification as the standard for equipment to be purchased in the future.
It was also agreed we should take account of the present higher level products being planned under the CR82 Ring programme and where possible use and contribute towards these initiatives.
The next full meeting is planned for February/March 1984 and a further report and discussion is hoped to be included in the next Networkshop.
Editor's -note : Ted Owen from Daresbury Laboratory is organising the Ethernet discussions on behalf of the JNT and provided the above article.
The JNT keeps a stock of all the coloured books but requests for multiple copies of any book should be addressed to the official source. These are now:-
Exeter University will continue to run Practical X25 Networking courses every vacation. The next course will be held from 12th to 15th December. Information and application forms may be obtained from Mrs Jackie Beard at:-
The Computer Unit, University of Exeter, EXETER EX4 4QE, Telephone (0392) 77911 ext 759
The following has been, produced for the Rutherford Appleton Laboratory's Forum newsletter:
The Joint Network Team has been in existence for over 4 years and the networking programme which it established has now yielded substantial results. These have been achieved partly through the funds which have been directed towards achieving the goals of the programme but mostly through the willingness of the academic community to pool its efforts and work together.
The strategy adopted is based on the principles of Open System Interconnection and the corresponding non-proprietary protocols which are used to ensure interworking between computers from different vendors. The JNT has recommended the use of certain protocols throughout the community with the intention of ensuring that any terminal or computer can communicate with any other for the purposes of terminal access, file or mail transfer and job shipment. The strategy also proposes unifying communications arrangements so as to simplify topologies, improve flexibility, increase reliability and reduce costs.
The JNT has two main programmes. The development programme seeks to augment the efforts of the community and manufacturers by funding the production of host computer protocol packages or network components for widespread use throughout the community. The installation programme provides funds to university sites for the purchase of campus networks and host computer interfaces. In addition to this, the recently established Network Executive is seeking to integrate wide-area communications to provide a single X25 packet-switched network for the academic community (JANET).
The table below shows the types of host systems where packages are now available to support the recommended protocols. The development programme is not complete and not all the systems listed support all the protocols. A system is included provided at least one of the user services (terminals, files, mail, jobs) is available.
| Company | System | Facility | Supplier |
|---|---|---|---|
| CDC | CYBER/NOS | TF | M |
| DEC | DEC-10/TOPS 10 | TFM | JU |
| DEC | VAX/VMS | TFM | JMU |
| DEC | VAX/UNIX | TFM | JU |
| DEC | PDP-11/UNIX | TFM | JU |
| DEC | PDP-11/RSX11M | TF | JMU |
| DEC | PDP-11/RT-11 | TF | JU |
| DEC | LSI-11/RT-11 | TF | JU |
| GEC | 4000/OS4000 | TF | M |
| Prime | PRIMOS | T | M |
| Honeywell | GCOS | TF | JU |
| Honeywell | MULTICS | TF | JM |
| IBM | MVS | T | M |
| ICL | 1900/GEORGE 3 | T | JM |
| ICL | 2900/VME | T | M |
| ICL | 1PERQ/PNX | TFM | JU |
The above list only covers packages which are available now as products with ongoing maintenance support (university suppliers are funded through the JNT to provide support). Further packages exist, for example for GEC and Prime systems, which are either not available as documented products or where there is no commitment to ongoing support for customers throughout the academic community. In many cases, these will be available soon from the manufacturer. The JNT believes in general that commercial rather than university supply and support is to be preferred and is pressing manufacturers to adopt products.
Development is continuing and other packages are in the pipeline. Job shipment can currently be achieved through an enhancement to the file transfer mechanism but will be available soon through a sophisticated Job Transfer and Manipulation Protocol.
Host computers are either connected to a wide-area network such as JANET or the public packet-switched network (PSS) or to a campus network. These networks are normally interconnected so that connection to one ensures communication with all other systems. The JNT installation programme provides funds to universities to implement campus network plans. Funds are provided to purchase components off the shelf rather than to enable local development.
Most existing campus networks use X25 packet-switching technology. This is primarily because work is more advanced than with the higher-speed Local Area Network technologies where a complete set of protocol standards or products are not yet available. About 35 university sites have now installed or have ordered networks based on GEC 4000 Campus Packet-Switching Exchanges and JNT Packet Assembler/Disassemblers (PADs or terminal concentrators). This means that over half of UK universities have a local medium-speed networking capability.
Higher-speed Cambridge Ring technology is also starting to come into use. The Computer Centres on 4 sites offer a Ring network service and a further 3 are planned. This is in addition to the large number of Rings installed for research purposes. Many sites are also considering plans for networks based on Ethernet technology.
Almost every university in the country now has some kind of access to the wide-area network. In some cases this may only be through a departmental machine provided for research purposes or may only be for terminal access. However, the population which can gain access is growing steadily and the quality of the connections is improving. The task of the Network Executive is to enhance the capacity of JANET, to provide general access to it by making connections available through university computer centres, and to rationalise the network topology.
Much progress has been made in the last four years and a large part of the academic community now benefits from the facilities available for Open System communications. However, much work remains to be done particularly in the area of Job submission and in the high-speed Local Area Network technologies. The emphasis is likely to shift in the next few years with more development done by manufacturers rather than universities as the outside world catches up and international protocol standards become available.
A meeting to discuss networking micros was convened by the London Network Team on behalf of the JNT and held on 6 June. Many installations already have networking facilities on micros through the use of terminal emulation techniques. The objective of the meeting was to discuss the provision of more sophisticated facilities using the Asynchronous Transport Service (ATS) protocol defined by the Transport Service Implementors' Group and the community's high-level protocols, in particular the Blue Book File Transfer Protocol.
The London School of Economics has produced an implementation of ATS in Z80 Assembler. This work has demonstrated the adequacy of the specification and has given a feel for the amount of effort involved and the space requirements. Alan Chambers of Bristol University is producing a reference implementation of ATS in a high-level language. He is also producing a specification of a standard procedural Transport Service interface to reduce the work in mounting high-level protocol software over ATS implementations.
Westfield College have produced a Pascal implementation of FTP to run under CP/M. The next stage in this work is to mount it over the LSE ATS.
Camtec Electronics are producing a proposal for providing an ATS capability on the JNT PAD. This would allow ATS systems to switch through the PAD and allow the micro's FTP to interwork with systems throughout the community. Provision of an ATS capability on an existing PAD may require a hardware upgrade to provide the greater memory capacity needed.
A second meeting to discuss progress is planned but has not yet been scheduled. Further details can be obtained from John Seymour, LNT, c/o ULCC, 20 Guilford Street. London WC1N 1DZ. telephone 01-405-8400.
Network News is published every four months and provides news for those interested in networking activities in the Research Council and university community. It is also circulated to polytechnics and interested manufacturers. Requests for copies or items for inclusion should be addressed to the editor.
Editor: B J Charles, Joint Network Team
