Networks at Syracuse University John M. Wobus Communications & Development Computing & Network Services Syracuse University February 28, 1989 Document Number: SUNETS-3 (c) Syracuse University Computing & Network Services 1989. Copy- ing, in whole or in part, is permitted only for educational pur- poses and copies must include this copyright notice. Copying or republishing for commercial advantage is prohibited. For permis- sion to republish or distribute, write to: Director of Computing & Network Services, Syracuse University, Skytop Office Building, Syracuse NY 13244. ABSTRACT This paper describes the various data-communications networks at Syracuse University, with an emphasis on those that directly serve teaching or research. This paper is for the general read- er, but does include some more technical information to allow it to also serve the technician who needs an overview of the sub- ject. Abstract ii CONTENTS Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . ii Networks at Syracuse University . . . . . . . . . . . . . . . . 1 Syracuse University's Networks . . . . . . . . . . . . . . . 1 ACSNET . . . . . . . . . . . . . . . . . . . . . . . . . 1 DECCS-LAN . . . . . . . . . . . . . . . . . . . . . . . . 2 The Internet . . . . . . . . . . . . . . . . . . . . . . 2 Microcomputer-Cluster Networks . . . . . . . . . . . . . 3 PC-Cluster Networks . . . . . . . . . . . . . . . . . 3 Macintosh-Cluster Networks . . . . . . . . . . . . . . 3 Departmental Networks . . . . . . . . . . . . . . . . . . 4 FASTNET . . . . . . . . . . . . . . . . . . . . . . . . . 4 BITNET . . . . . . . . . . . . . . . . . . . . . . . . . 4 DECnet . . . . . . . . . . . . . . . . . . . . . . . . . 5 Administrative Information Systems IBM 327X Network . . . 5 Academic Computing IBM 327X Network . . . . . . . . . . . 5 Current Networking Projects . . . . . . . . . . . . . . . . 6 Science and Technology Building . . . . . . . . . . . . . 6 Workstation Cluster . . . . . . . . . . . . . . . . . . . 6 Other Future Goals . . . . . . . . . . . . . . . . . . . 7 Managing the Complexity . . . . . . . . . . . . . . . . . . 7 The Problems . . . . . . . . . . . . . . . . . . . . . . 7 The Solution . . . . . . . . . . . . . . . . . . . . . . 8 Appendix A: Some Terminology . . . . . . . . . . . . . . . . . 9 Types of Cable . . . . . . . . . . . . . . . . . . . . . . . 9 Low-level Protocols or Networks . . . . . . . . . . . . . 10 Full Networks or protocols . . . . . . . . . . . . . . . . 11 Networks at Syracuse University iii NETWORKS AT SYRACUSE UNIVERSITY Syracuse University has a number of networks. They developed independently because: * Applications for data communications networks are not all alike: some applications cannot be served by some types of networks and often the difference in cost between serving an application with one or another type of network is very large. Some networks are nearly 'universal' but such net- works are very expensive for at least some network applica- tions. * Many computer vendors have developed their own proprietary networks. Such networks are generally very easy to install and operate when they serve their vendor's own computers.(1) In those cases where it is advantageous, the University's net- works have been joined together so the users of one network get the benefits of other networks. This paper describes these net- works, their current uses, and plans for future expansion. SYRACUSE UNIVERSITY'S NETWORKS ACSNET ACSNET is a low-speed network that provides low-cost connec- tions between large computers and terminals or personal computers anywhere in the classroom or research buildings on campus. It serves over 1500 terminals and personal computers, providing them with direct access to 5 large computers and 2 other networks. It is built around an Imaginet IDX-3000 network switch, and can be easily expanded to handle 2000 terminals and personal computers. A terminal or personal computer is attached to the network through ordinary telephone wire using short-haul line drivers. In each building, time-division multiplexors multiplex the data to just two twisted-pair per every 24 devices, thus reducing inter-building wiring. The large computers can be located any- --------------------- (1) Thus the proliferation of networks thus reflects the prolif- eration of computers. Two of the major reasons why different kinds of computers have proliferated on campuses are: differ- ent departments and people on campus need different types of software whereas all computers don't offer the same software; and an academic department often depend upon exchanging soft- ware or data with analogous academic departments at other universities, making it very advantageous to choose the type of computer most common to their own type of department. Networks at Syracuse University 1 where on campus and special hardware makes attachment of Digital Equipment Corporation VAX computers easier and less expensive. ACSNET also can provide dedicated channels for purposes other than terminal sessions, such as inter-computer communications (with the help of suitable software) or remote printing. ACSNET grew out of the University's need to provide computer service to thousands of people at a low cost. DECCS-LAN DECCS-LAN is a service provided by New York Telephone (Syra- cuse's local telephone operating company). It is very similar to the service provided by ACSNET, but is available over a wider area (including much of the city of Syracuse). It is based upon an ATT Datakit network switch located at New York Telephone's central office for the city of Syracuse. It uses line drivers which can share the same wires as ordinary voice telephones. It has two advantages over dialing in to ACSNET through a dialup modem: it is faster, and you can use the telephone at the same time as you use the attached terminal or personal computer. DECCS-LAN gives its subscribers the ability to connect to ACSNET, thus offering them exactly the same set of services. The University finds this service useful not only to serve points off campus but to serve some points on campus which are difficult to wire for ACSNET service. The Internet The Internet is a world-wide network made up of hundreds of interconnected smaller networks acting cooperatively. It includes university campus networks, nation-wide networks, regional networks, corporate networks, and government networks, all operating at different speeds. They all use a common proto- col (TCP/IP) which is designed to make connected networks act as one large network. For example, to sign on to a computer at another university that's on that university's network, one needs only that computer's official "Internet" name. Routing the data to and from that computer through any number of intervening net- works is handled automatically. The Internet offers three basic services between the comput- ers: electronic mail; transferring files of data; and interac- tive sessions (i.e. if one sign on to one computer in the Inter- net, then one can sign on to another computer on the Internet just as if their terminal or PC were directly attached to it). With appropriate software, computers on the Internet can also offer and use other services such as file sharing between differ- ent computers and the operation of graphics terminals at other locations. Networks at Syracuse University 2 Syracuse University's Ethernet departmental networks and FASTNET are all part of the Internet. They presently serve 24 large computers and about 300 PCs and workstations. In addition to allowing these computers access to the world, it offers them a uniform way to communicate with each other through Syracuse Uni- versity's fastest networks. Microcomputer-Cluster Networks Syracuse University Academic Computing Services operates five "microcomputer clusters", basically rooms filled with microcom- puters for the use of the University community. They include IBM-PC compatible or Apple Macintosh computers. Each cluster is built around a high-speed network so its computers can share ser- vices. PC-Cluster Networks There are five PC-Cluster networks, which are based upon Novell Netware software and ARCnet hardware. All the PCs in the cluster can share file and printing services. This combination of hardware and software inexpensively provides excellent service to IBM-compatible PCs within a single room, but would require special building wiring to serve PCs that are more scattered than that. The PC-clusters are all interconnected through a series of ARCnet links to facilitate file backups, etc. Macintosh-Cluster Networks There are five Macintosh-cluster networks, which are based upon Appletalk, Apple's proprietary network protocol using Pho- neNET, Farallon's Appletalk hardware. All the Macintosh comput- ers can share printing and file services. PhoneNET serves Macin- tosh computers with a combination of low cost and flexible configuration through ordinary telephone-style wiring. The Macintosh cluster networks are interconnected using FASTNET, and a Campus-wide file-server makes data and programs available to all the cluster networks as well as departmental Macintosh net- works. The SUACS Microcomputer Clusters grew out of Syracuse Univer- sity's need to offer the use of personal computers for classwork at a reasonable cost to the University. Networks at Syracuse University 3 Departmental Networks Many departments at Syracuse University, both academic and administrative, have private high-speed local-area networks. These typically span a building or a portion of a building. They include the following types: * Networks of IBM-compatible personal computers. These are generally based upon Ethernet, ARCnet, or IBM Token Ring hardware and either Novell or IBM software. * Networks of Apple Macintosh computers. These are generally PhoneNET or Localtalk. Some of these networks are connected to other Macintosh networks on campus and to the Internet. * Networks of technical workstations. Generally, they networks of Sun workstations, tied together using TCP/IP running over Ethernets. FASTNET FASTNET is a network that spans the campus of Syracuse Univer- sity, interconnecting several departmental networks. This links together all of the major academic computers and almost all workstation-type computers (such as Sun workstations). FASTNET consists of 10 "network gateways" located in 8 different build- ings tied together via high-speed communications lines. These gateways are built by Proteon Corporation and Cisco Corporation and are capable of interconnecting various kinds of networks and moving data between them. Ethernets in these eight buildings are tied to FASTNET via the gateways. Seven additional buildings are served through fiber-optic Ethernet repeaters. FASTNET carries Internet and DECnet data traffic between the Ethernets. BITNET BITNET is a world-wide cooperative network of academic comput- ing centers of universities. It supports electronic mail and file transfer between large computers. It is based upon IBM's non-SNA software and protocols for interconnecting mainframes. It uses NJI/NJE protocol running over BSC lines, IBM CTCA adaptors, and piggyback over TCP/IP or DECnet. Under VM/370 and its successors, it uses the RSCS networking software and under OS/VS2 Release 2 and its successors, it uses JES2 or JES3. BITNET members have created software implementing one of these protocols to allow other computers to join BITNET (JNET for Digi- tal Equipment Corporation VAX computers; and UREP for computers running Unix). Networks at Syracuse University 4 Syracuse University has four computers in BITNET. Syracuse University uses this network for intra-campus mail and file transfer as well as that with other universities. Syracuse University joined BITNET because it was the largest of the cooperative inter-University networks and because Syracuse University's use of IBM mainframe software minimized the effort to join. DECnet A DECnet is the collective name for the software and hardware products sold by Digital Equipment Corporation and that use the DNA communications protocol, a protocol invented by Digital Equipment Corporation. The name "DECnet" is also used to desig- nate any network that uses DNA. Syracuse University's DECnet interconnects Syracuse Universi- ty's academic-oriented Digital Equipment Corporation VAX computer systems. It provides electronic mail, file transfer, remote file applications, and remote terminal sessions between these comput- ers. DECnet communications links can be run over synchronous lines, asynchronous lines, Ethernets, X.25 packet switched networks, or the "CI bus" which is Digital Equipment Corporation's bus for handling disk and tape systems shared between VAX computers. Syracuse University's DECnet uses Ethernets, FASTNET. Syracuse University uses DECnet because it is easy and inex- pensive to install and maintain and provides excellent service when used to tie together Digital Equipment Corporation's VAX/VMS computer systems. Administrative Information Systems IBM 327X Network The Administrative Information Systems IBM 327X Network pro- vides access to Syracuse University's online administrative applications to administrators and departments located throughout the campus. It is based upon IBM's 3270-type terminals and com- patible remote concentrators. It grew out of the University's need for a separate, more secure network for administrative applications, and the compatibility of this type of terminal net- work with the administrative applications software. Academic Computing IBM 327X Network The Academic Computing IBM 327X Network delivers the timeshar- ing services of an IBM mainframe (with the VM operating system) Networks at Syracuse University 5 to nearby offices. It is built around IBM's hardware for locally attached 3270-type terminals. It grew out of Academic Computing Service's requirement for maintaining and developing software as efficiently as possible for the IBM mainframes, and the fact that IBM mainframe software supports 3270-type terminals better than any other type. This network is a cost-effective alternative to ACSNET where a user uses VM exclusively and is located near the mainframe (same or adjacent building). CURRENT NETWORKING PROJECTS Syracuse University, like many other universities, is in a period of rapid network growth. Existing networks are growing, they are being integrated more closely, and entirely new networks are being planned. Some of the most striking expansion during 1988: * Installation of fiber optic cable between over 20 major cam- pus buildings. * Upgrading much of the telephone intrabuilding distribution cable, with extra telephone wire reserved and ready for data communications applications. * Instigation of DECCS-LAN service. * Rapid expansion of Internet service throughout the Universi- ty, making it available to about 300 computers of all types. * Rapid expansion of a campus-wide Appletalk networking service providing Macintosh users with central file and printing ser- vices. Below are some networking projects currently in various stages of planning and installation: Science and Technology Building Syracuse University is building a building devoted to that part of engineering and the sciences that are highly computer- ized. The building will be prewired for state-of-the-art data communications and will also have ready-made paths for installing any future wiring that will be needed. It will include several state-of-the-art departmental networks. Workstation Cluster Syracuse University is opening a workstation cluster, analo- gous to the microcomputer clusters except that it will be built Networks at Syracuse University 6 around Sun workstations rather than IBM PCs or Apple Macintosh computers. This will offer faculty, staff, and students consid- erably more computing and graphics capability than the microcom- puters. It will be located in the Science and Technology Build- ing. It will be tied together by an Ethernet, which will, in turn, be connected to FASTNET. Other Future Goals * Practical electronic mail service available to all types of computers on campus. * Adoption of standard types of networks: ISO/OSI for high- speed networks and ISDN for low-speed networks. * Replacement of ProNET-10 with FDDI, a standard network cur- rently under development with 10 times the throughput over the same cable. MANAGING THE COMPLEXITY The Problems It is clear that the University now has many different types of networks. Where a the choice of a specific type of network might have an overwhelming advantage to a particular department, the proliferation of types of networks creates some problems to the University as a whole: * Networks grow out of the need to exchange data: when the users of one network later discover they need to exchange data with the users of another, connecting the networks will be much easier if the networks are of the same type. Con- necting networks of different types often means purchasing and installing special options or third party products; these range from being inexpensive and easy to being unreliable, impossibly expensive, or non-existent. Furthermore, using these "special network connections" almost always requires additional knowledge. * Provision of a computer consulting service to the entire cam- pus is much more difficult when it has to take into account all the different types of networks. * Overall physical planning and budget planning requires more specialized knowledge. Networks at Syracuse University 7 * Troubleshooting of problems requires more specialized knowl- edge.(2) The Solution There is no instant solution. The hope is that the future will bring sufficient standardization of the data communications industry (and a critical degree of acceptance of these standards) that any network the University acquires will be readily attacha- ble to any other network. This laudable goal has not been achieved, but is currently being pursued by the International Standards Organization (ISO) and many data communications equip- ment vendors. Defining standards at the international level takes years, and though the ISO has been working for at least ten years on the project, they still have years to go. The Universi- ty continually monitors such standards and market developments to take advantage of them. Some ways the University is pursuing this are: * Some of the types of standard cable have been specified. The University looks for ways of using standard cables when plan- ning new networks. * Some of the standard "low-level" protocols have been speci- fied. Once again, where a choice presents itself, the Uni- versity looks for ways to use the standard protocol. * Some networking equipment is "adaptable", i.e. can be made change the way it works by changing software rather than replacing the hardware. The University looks for equipment which will can be adapted to future standards via future software upgrades. In the mean time, the University tries to make do with what is available. Some types of networks are readily connected togeth- er, or good products are available to do so. And different types of networks vary in how many different types of computers they can serve and how well they can serve them. The current "champi- on" type of network is TCP/IP (which is the basis for the Inter- net), which has gained large acceptance by being the choice of a large customer (the U.S. Government) and by being included in the Berkeley Unix systems software, which is used on many different types of workstations and large computers. --------------------- (2) This list of disadvantages is formidable enough to make one wonder why such a proliferation shouldn't be prevented by fiat. See the beginning of this document for the counterba- lancing reasons for the proliferation. Networks at Syracuse University 8 Appendix A SOME TERMINOLOGY TYPES OF CABLE Example: telephone wire (unshielded, twisted-pair copper cable). Once cable of a particular type has been installed, its use can be varied by switching the electronics and software that use it. The differences in the way it is used may be a change in the format and procedures for exchanging data (probably control- led by software running on the computers) or it may actually be physically-related like a change in the voltages used to carry data. Some terms used when describing cable: trunk Cable between buildings. riser Cable between floors of buildings. distribution Cable from one site of a hallway (the "telephone clos- et") to a particular room on the hallway where it is attached to a computer (or telephone). Types of cable: Telephone Also known as (unshielded) twisted-pair cable. In trunk and riser cables, it is usually bundled into some large number of pairs of conductors, so a single cable supports many data communications connections or tele- phone connections. Distribution cables typically sup- port only a small, fixed number of connections (one to four). It is the lowest cost cable, but has the least capacity. For this reason, and because it also serves telephones, it is installed "nearly wherever possible" even if no need for data communications is perceived yet at a particular site. Note that nearly any low- level protocol can be run over telephone wire. Vendors have made sure their protocols can use it because so many of their customers already have telephone wire installed. However, there are almost always trade- offs: sometimes the distance is severely limited, some- times there is costly electronics that needs to be placed at each end of the telephone wire, and sometimes there is a danger of such circuits "interfering" with each other when run in adjacent circuits. Fiber Most often used for trunk cable, can also be used for riser or distribution. Like telephone wire, it is often "bundled" when installed as trunk cable. The University has a system of multi-fiber trunk cables Networks at Syracuse University 9 between over 20 major buildings. It is 62.50 micron which is the "best guess" as a future standard. RG62 Coaxial Most often used within buildings, but is used as trunk cable too. Standard Ethernet Cable Also known as Thickwire. Most often used under raised floors (in computer rooms) or as riser cables. Can also be used for trunking or distribution. Thinwire Ethernet Cable Most often used for distribution. Shielded, twisted pair Most often used for distribution. The usual cable for Token Ring. LOW-LEVEL PROTOCOLS OR NETWORKS Example: Ethernet. This is a level that the user usually doesn't have to deal with except when choosing the appropriate hardware and software to plug into a network. A particular low- level network can make use of various types of cable and provide fast, but rudimentary data transfer capability. Changing your computer to use another low-level protocol typically means using different hardware interfaces to attach the computer to the cable. Often, it requires changing (or reconfiguring) some of the software too. A single cable can support only one low-level protocol at any one time--all computers attached to the cable must agree. However, a cable running a particular low-level pro- tocol can often support more than one full protocol simultaneous- ly. Some computer vendors have advanced their own low-level pro- tocols, but they often choose one already in use, and the industry has been fairly successful in agreeing upon standards (as compared to the area of full protocols). Ethernet Can be run over either type of Ethernet coaxial or fiber. Can also be run over telephone wire with some disadvantages. A favorite of DEC, SUN, and Xerox. Localtalk Uses special "Localtalk" cable. Invented by Apple for the Macintosh. See PhoneNET. PhoneNET An improved version of Localtalk which uses ordinary telephone wire. Though the cable and electrical char- acteristics are different, it works with anything that works with Localtalk. ARCNet Uses RG62 Coaxial or fiber. Invented by ARC, but used most for Novell networks. Some Terminology 10 3270-coaxial Uses RG62 Coaxial, or telephone wire. ProNET-10 Ring A proprietary protocol of the Proteon Corporation. Typically, fiber is used between buildings and shielded-twisted pair is used within buildings. Asynchronous Serial Uses telephone wire. Used for low-speed communications by Asynchronous-ASCII terminals and personal computers communicating with large computers. Synchronous Serial Uses telephone wire. It is not standard to the degree that equipment made by two vendors will be able to com- municate just for using synchronous serial. Among the vendors with different standards are: * Proteon * CISCO * IBM (with two, known as SDLC and BSC) Token Ring Developed by IBM but now a standard. Generally uses shielded-twisted pair, but can use telephone wire. FULL NETWORKS OR PROTOCOLS Example: DEC's DECnet. This turns the "rudimentary data transfer capability" into services the user is likely to ask for: moving a datafile from one computer to another; sending electron- ic mail to another computer user; etc. The choice of full proto- col is nearly always determined by the software running on the computers. Most computer vendors have developed their own full protocol (some have developed more than one) and some network vendors have developed their own. Adapting computer X to use full protocol Y has become a significant amount of the software work done by the computer industry (thus a significant cost to the users). Standardized, non-proprietary protocols are gaining popularity with users, and even vendors. One peculiar (and sometimes confusing) fact is that one full network may be made to use another full network as if it were a low-level network ("piggyback" would be an appropriate phrase). TCP/IP Also know as "internet" or "the internet suite". Developed by research contracts of the Department of Defense. As a government-sponsored protocol, widely used by the Department of Defense, most computers have been adapted to use it. Other users have made the most Networks at Syracuse University 11 of this, adopting it for their own use. Hardware and software is available to make virtually any computer use it. TCP/IP can run over Ethernet, ProNET-10, Pro- teon's synchronous serial, and CISCO's synchronous serial protocols. The Internet is an example of a TCP/IP network. Novell Netware A proprietary protocol developed by Novell. It has been very popular for connecting IBM PCs (and compati- bles). They have recently adapted it for Macintosh computers too. It can run over ARCnet, Token Ring, Ethernet, and ProNET-10. Appletalk A proprietary protocol developed by Apple specifically for the Macintosh. A version of it has been developed for Unix to make a Unix system serve as a "file server" for numerous Macintosh computers. It can run over Localtalk, PhoneNET, or Ethernet. It can also piggy- back on any TCP/IP network. DECnet A proprietary protocol developed by Digital Equipment Corporation. Generally, only computers sold by DEC support it. It can run on Ethernet, ProNET-10, Pro- teon's synchronous serial and CISCO's synchronous seri- al protocols. 3270 A protocol IBM invented to attach their terminals to their mainframe computers. Can run on 3270-coaxial or IBM's BSC. as well as piggyback on TCP/IP, Appletalk, or SNA. Software for various microcomputers and work- stations can make them act like IBM terminals. ASCII Asynchronous Used by most vendors other than IBM to attach their terminals to their mainframe computers or minicomput- ers. Can run on telephone wire, and through the dialup-telephone system (off campus). Can also piggy- back on TCP/IP or DECnet. ACSNET is an example of an ASCII Asynchronous network. SNA A proprietary protocol of IBM designed to interconnect large computers. Runs on IBM's SDLC. NJI/NJE A proprietary protocol of IBM originally designed to attach mainframes to remote line printers and card readers. IBM developed SNA to replace it. Runs on IBM's BSC. BITNET is an example of an NJI/NJE network. Chaosnet A protocol developed by MIT for workstations. Used by Lisp Machines. Runs on Ethernet. Kermit A protocol designed to run piggyback over ASCII Asynch- ronous, which can move files between computers. Some Terminology 12