Data Does Networking |-------------------------------------| | Paper presented at CAUSE92 | | December 1-4, 1992, Dallas, Texas | |-------------------------------------| DATA DOES NETWORKING! Gene T. Sherron, D.B.A. Professor of Information Studies Florida State University ABSTRACT Since the beginning of computing back in the 50s, weÕve been doing data. But, my, have times changed! Today, data moves at 100 megabits (Whatever that is!) and everybody is doing his own LANs. Driven by the garage-born micro, the users are extending the power of computing into the workplace by doing much of their own ÒnetworkingÓ with a child-like faith that they ought to be able to do data as easily as making phone calls. Well, why not? The purpose of this paper is to present current information, in laymanÕs terms, about networking and data communicationsÑthe range of options open to us and indications of what campuses are doing with this communications technology. It is not designed as a techie paper. In January 1990, CAUSE published a voice communications professional paper entitled An Information Technology ManagerÕs Guide to Campus Phone Operations. In some respects this is a ÒsequelÓ except for the fact that it is data-oriented. So, look to learn about topology, media, compatibility, LAN software, and like stuff. Experts need not attend! I. INTRODUCTION Networking in the Latter Years of the Information Age. It has been a long-standing need of man to communicate. Forget the drums, bonfires, semaphores, and flashing mirrors of years gone bye. Today, managers rely on phones as the prime instruments for communications. They are simple, fast, ubiquitous, and geographically boundless. Yet, depending on which statistic you wish to accept, somewhere between 50 and 90 percent of business phone calls go unanswered on the first try. This annoyance, plus a general interest in reducing paperwork, has caused all sorts of people to be eager to try electronic mail (e-mail). Its acceptance is making it second only to the phone as essential office equipment. By the way, does it register in our minds that FAXing is electronic mail? And even today, few people understand all of the technical aspects of connecting people electronically, but managers know what they want-- "everything is connected to everything."[1] Yet, it is one thing for the president to tell us to get connected, and quite another to be implemented. So, how do we get our arms around these issues? Perhaps, what we need is a quick cram course on e-mail and its associated technology. The techie stuff includes such things as local area networks (LANs) to hook-up the offices and the software (operating systems and protocols) to drive these systems. Thus, we end up with a bit more on our plate, but at least a half a dozen topics are critical to our understanding of LANs, networking, and data communications. II. NETWORKING Some defining--Doing some networking? Whether we call it networking or local area networks (LANs), selecting the scheme for your campus is no simple task. Today's networking/LAN marketplace is crowded with at least fifty different vendors, all claiming that their product is THE one you need. Further confusion occurs because there are few standards in networking, de facto or otherwise. Nonetheless, you may be sure that the simple, small LAN you install today will turn into a large, multifloor, multibuilding, or multicampus network in the not too distant future. In terms of size, the network will only grow. The multivendor approach will likely become more multi. The applications we run across the network will continue to vary in diversity. And, the unpredictable usage will be the norm. In a formal sense, a network is one or more communications circuits and associated equipment that establish connections between nodes (users).[2] (Unfortunately, you'll have to wait until later in the paper to fully appreciate some of the words in this definition.) In terms of the technology that makes a local area network, it can be said that a LAN consists of some hardware, software, cabling, and connectors. The hardware is typically a PC and some added internal electronics. The software comes to us from dozens of vendors that provide a LAN operating system and applications software products. The cabling can be twisted pairs, coax, and/or fiber. And, connectors-- such as interface cards, transceivers, and cable connectors-- provide the linkages between the nodes and the medium. LANs have proven their value in organizations that range in size from small offices to far flung university campuses. By definition, most local area networks connect users within a single building. Yet, as they become more and more popular in an organization, LANs expand to adjacent buildings. And before you know it, connections are needed beyond the LAN to a city or metropolitan area network (MAN) or even to national and international networks or wide area networks (WANs). Rational behind LANs--A well-designed LAN can deliver many important benefits. First, it allows users to share organizational resources such as databases, graphic devices, high-speed laser printers, and mass storage devices. Such sharing can increase the use of scarce resources, improve individual productivity, and promote efficiency. It might even allow us to place less emphasis on making and filing paper copies and, as attitudes change, may even reduce intraoffice paperwork. Now, let's get into the details. III. TOPOLOGY As networking progressed, it became evident that names would have to be given to the different methods of getting all these users wired together. You'll hear people refer to these grand designs as network architecture, or the more functional title of network topology, or cabling configurations--as some prefer. More frequently, people like the phrase wiring topologies, so that will be our title for this section. The basic topologies are: bus, ring, and star. However, in practice, we find a number of wiring schemes that are mixtures of these basic topologies. Networks with the bus topology sometimes are called backbone networks because they connect each device to a central cable called the backbone. IV. MEDIA Our LAN's electronic transmissions move over highways of cables. These cables are the different media. We usually think of cabling as copper wires, but more recently, glass (optical fiber), is gaining popularity as a LAN medium. LANs are typically cabled with copper and it comes in many varieties. But, one observation at the outset: There is no one best cable for LANs!. As suggested earlier, the medium for your campus may be a matter of historical consequence or thoughtfully chosen, based on present and long-term requirements for data, text, graphics, voice, image, and video. Media selection is a very important aspect of LAN development. If you choose incorrectly, the LAN may not be able to support future loads or may introduce reliability problems. Some of us get "stuck" with an existing cable plant that would cost millions to dig-up and replace. This wire that stretches from the wiring closet to the end user, or the horizontal wiring, represents about 85 percent of the cost of any rewiring program. So, with so much of it already in place for the phone system, you can bet that unshielded, twisted-pair copper will remain the horizontal medium of choice during the coming years. V. NETWORKING STANDARDS The Need for Standards--Back in the 1950s there were no rules, let alone standards, for data to be communicated. In fact, the need for one computer to talk to another computer just did not exist. But, over the years and decades, networks and telecommunications systems evolved, people in the business realized that each system should continue to be unique and specially developed. LAN Standards (The 802 Committee)--Because our LANs tend to spill over into national and international networks, several professional organizations have initiated efforts to standardize various aspects of networking. The work of the Institute of Electrical and Electronics Engineers (IEEE) 802 Committee is the best known for LAN standardization efforts. Since it was founded in 1980, the 802 Committee has approved a standard family for LANs and established several different network access protocols. A few of the more significant ones are highlighted below: 1. 802.3 CSMA/CD and Ethernet This standard addresses a variety of CSMA/CD architectures that are generally based on Ethernet. One of the early subcommittees, it began with 1BaseT and is progressively working on other developments: ++ 1BaseT -- The early one is referred to as 1Base5, which means 1 Mbps across a baseband medium with a maximum length of 500 meters. This standard encompasses the more commonly known implementation named Starlan by AT&T. ++ 10Base2 -- Gaining recent popularity is Thinnet or Cheapernet, or a 10 Mbps baseband segment of up to 200 meters. ++ 10BaseT -- The renaissance of copper twisted pairs has been sparked by this standard of 10 Mbps baseband signals. 2. 802.5 Token Ring Token-Ring is IBM's LAN methodology which features a single, baseband ring topology. It operates over twisted pairs, but can accommodate more PCs if data-grade cabling (coax or fiber) is used. IBM began its token-ring running at a speed of 4 Mbps. Today, you can buy either 4 Mbps or 16 Mbps Token-Ring. Shielded twisted pair (STP) type cable is the most robust installation and is preferred for all new rings. However, many cable manufacturers insist that 16 Mbps run just fine over unshielded twisted pair (UTP). A Standard Interconnection Internationally, in order to facilitate linking systems, a model was developed the International Standards Organization (ISO) which, along with several telecommunications vendors and CCITT, that became known as open systems interconnection (OSI) reference model. Since 1978, work has been underway to convert the model into a set of standards by precisely defining each part of the layers of the model. The architects of the ISO-OSI model had as their primary objective to provide a basis for interconnecting dissimilar systems for information interchange. The idea being, if they defined the rules or protocols of communication, and if followed, incompatible systems made by different manufacturers would be able to "talk" to each other. As open systems have risen to the forefront in networking, standards are currently evolving from two directions Open Systems Interconnection (OSI) and Internet. The Open Systems Interconnection Model CCITT X.200 is the designation for Open Systems Interconnection (OSI) which is referred to as the Basic Reference Model for open-systems type of networking architecture. Announced in 1978, the OSI model uses a layered approach, with each layer representing a component of the total process of communicating. One way to view this model is view hardware on the bottom or layer 1. At the top is software or layer 7. In between are varying amounts of each. All of the layers in-between describe the standards that handle the necessary elements of control. The bottom three layers--Physical Link, Data Link, and Network Control--of the OSI model are well-defined. Standards have been written and agreed to. The combination of the first three layers is the X.25 standard for data transmission used in packet switching networks. As one moves on up the scale of the layers, the complexity seems to grow. Many standards are required to address all of these areas and the work will go on for years. Future Directions With less than two percent market penetration, OSI's future does not appear bright. Adopting certain parts of OSI will provide added value to users; and for some even full OSI implementation will be of value. The lower layers of the OSI model have provided for better multi- vendor connectivity and internetworking. And such standards as X.400-- the de facto standard for electronic mail--and the emerging X.500 may become THE standard for directory services. VI. LAN ARCHITECTURES Ethernet--As discussed earlier, Ethernet, is one of the three oldest architectures--token bus, token ring, and Ethernet. The original implementation was with coax or thick Ethernet. Today, in addition to shielded "thick" coax, which supports devices up to 500 meters, Thinnet or Cheapernet coax is about half the size of regular coax. However, it reaches out only about 185 meters. The two sizes of coax offer the advantage of using thick coax for a backbone application, with "skinny" coax being used as spurs to buildings. Still the dominant LAN architecture, Ethernet's growth is directly tied to the price of adapter cards (network interface cards) which has run at 40 percent a year for several years. AppleTalk--Second in popularity in campus LAN architecture, AppleTalk is increasing in numbers in the workplace. To facilitate this occurrence, Apple builds its Macs with internal network interface cards and the software to support what it calls AppleTalk. Using either Apple-provided twisted pairs or coax, this unique "standard" supports up to 32 Macs or printers at a relatively slow speed of 230 Kbps. Designed with a CSMA/CD type of access protocol, its workstations can be arranged in a bus or star configuration. Interfaces also exist that allow Macs to connect to LANs having IBM PCs or clones. Token-Ring--Growing almost as fast as Ethernet, IBM's LAN product is token-ring. It dominates market share in the sale of IBM token-ring adapter cards. These cards generally conform with IEEE 802.5 using baseband transmission on either shielded or unshielded twisted pairs. A network interface card (NIC) is used to connect the workstation to the token ring on one end. A multi-station access unit (MAU) is used to interconnect 4, 6, or 16 users to the network. ARCnet--As mentioned earlier, ARCnet was developed to connect minicomputers. It uses a token passing bus or star architecture but does not conform with the IEEE 802.4 standard. The reason is simple. It came in to being almost a decade before standards were even developed. ARCnet is one of the more popular LANs because of its early availability for PC-based LANs, relative low cost, flexibility, and well-recognized de facto standard. Starlan--Starlan has been standardized by the IEEE 802.3 subcommittee under the 1Base5 standard. Using the CSMA/CD access protocol, it can support an unspecified number of nodes on a cable up to 500 meters long. Starlan is an AT&T methodology, star-oriented, and provides l Mbps speed. One early advantage of Starlan is that the scheme uses plain old twisted-pair telephone lines that are already in most buildings. Also, it uses the CSMA/CD scheme and accepts multiple operating systems to include MS-DOS and UNIX. Future Directions--One need not look too far to find evidence of the effect that unshielded twisted pairs of copper has had on the LAN marketplace. Recent market reports show that over 60 percent of all new Ethernet sales are using UTP cable. Imagine, over 6 million Ethernet connections will be made this year. The 10BaseT standard has worked its way ahead of Token Ring with price driving the buying decision. 10BaseT can be purchased for approximately $275 per port, compared to $500 to $700 per port for Token Ring.[3] FDDI networks operating over copper or Copper Distributed Data Interface (CDDI) at 100 Mbps are predicted to throw traditional Ethernet and Token Ring networks from their current leading market position by 1997. Spurring the takeover are faster PCs and resource-hungry applications such as imaging and full-motion video. The acceptance of copper versus fiber is a matter that it is cheaper, and most people already have lots of copper. At issue is how long it will take the American National Standards Institute (ANSI), which has been working for copper standards since mid-1990, to provide an ANSI-standard for product development. Expect it in 1993.[4] VII. LAN OPERATING SYSTEMS The issue in systems management in LANs is that of determining what level of service is required/desired. That is, do we need a network for occasional e-mail use, or are we dealing with more complex database management processes and need tightly coupled overall control because the applications span many departments and machines? In either case, we need to meet the range of user needs in a cost-effective manner. Over the past decade or so of growing complexity in networking, users have quietly hoped for network control that doesn't appear to "control." But rest assured, the more usage and users, the more control will be needed. A LAN, or network operating system (NOS), provides a certain transparent "manager" of the system's resources. Novell's NetWare--The dominant leader in the NOS business is Novell's NetWare. Novell offers at least seven network operating systems (NOSs), as well as custom server hardware on which those NOSs run. Five of these run on IBM/IBM-compatible systems, one is for Macintoshes, and one for DEC VAX systems. One significant feature of Novell is its system fault tolerance (SFT) that provides an environment in which, if certain hardware failures occur, the network does not necessarily go down. For almost two years, IBM has been selling "NetWare for IBM" which gives users a Big Blue direction for now. Banyan Vines--Banyan Vines is recognized for its support for large networks and network interconnections. One of the very few to run on Unix-based servers, Banyan has a distinct advantage in the market place because many WANs contain nodes that run Unix operating systems. Few can match Banyan's multi-user, Unix-based machines support. IBM's LAN Server & OS/2--Although slow in coming, it appears that IBM wants you to do your data communications, multi-tasking, and presentation services via its latest versions of IBM's operating system or OS/2. So, mark LAN Server "out" and OS/2 as "in." However, IBM versions support only IBM token rings, not IEEE standards. An extended OS/2 version has enhanced capabilities such as the LAN Server and a communications manager. Microsoft's LAN Manager--In 1991, we noted that Microsoft was failing to resuscitate LAN Manager. This year it is apparent that the Microsoft emphasis is on Windows Workgroups and NT. Whether these products will or can take a bite out of Novell's huge market share will be based on market acceptance of these new products. 3COM's 3+ & 3+OPEN--Founded by the inventor of Ethernet, 3Com has been a leader in LANs from its very beginning. The latest 3Com offering, LAN Manager, runs under Microsoft's OS/2. 3Com's 3+Open is the OS/2-LAN Manager product sold directly by 3Com. Microsoft also provides its own version of LAN Manager. 3+Open goes beyond just supporting Ethernet and handles token ring architecture as well. Like Novell, LAN Manager provides fault tolerance via mirrored disk drives. And, like Banyan Vines, 3Com has announced a name directory service. DEC's Pathworks--For years, DEC has offered its own NOS, but competition has been stiff. Consequently, Digital has quietly introduced a product called Pathworks that walks the fine line between a NOS and DECnet. Pathworks ties into high-level services provided by DECnet and builds bridges to other PC-focused NOSs such as Novell's NetWare, Banyan's Vines, and 3Com's 3+Open. Using client and server software, Pathworks accomplishes this balancing act on the client side with PCs, Macs, and ULTRIX users getting basic mail application, network transport software, terminal emulation, and VMS application support. Server software provides users with print, file and mail services and support for TCP/IP, DECnet, and OSI. And, the server can be VMS, UNIX, or OS/2 based. The Digital strategy with Pathworks is to provide a corporate NOS to integrate all popular LAN technology and support all standards.[5] Future Directions--Have you considered that the lines between general- purpose operating systems, such as DOS, Apple's System 7, and OS/2, and network operating systems, such as Microsoft's Windows Workgroups, are blurring as each acquires attributes of the other? As the number of LAN- connected PCs rises along with the network-intrinsic applications, the division between operating systems and networking operating systems is becoming less and less. Perhaps, by the year 2000, we will have merged OS and NOS! VIII. PEER-TO-PEER LAN OPERATING SYSTEMS Peer-to-peer networking enables users to share files and printers without a file server. Products to serve this market have been provided by about a dozen vendors for years. For a number of years, LANtastic, 10Net, Web, and TOPS have been the bread-and-butter lines for peer-to- peer networking. Apple's System 7 was the first major vendor to make peer networking capabilities inherent in an operating system. Novell recently jumped into the peer networking bandwagon with NetWare Lite, a low-end, peer- to-peer version of its flagship server-based NetWare NOS. In late 1992, Microsoft became the newest player to enter this market with its built- in peer networking capabilities in Windows for Workgroups. Critics are quick to point out that Microsoft is not providing another peer network operating system but merely adding simple file and print capabilities to Windows. Additionally, it does not support any "clients" except Window's clients. In contrast, all major peer NOSs support DOS, Windows, OS/2, and Apple's Macintosh. However, for current Windows users, upgrading to Workgroups may be a good step.[6] IX. NETWORK-TO-NETWORK CONNECTIONS Transmission Control Protocol/Internet Protocol (TCP/IP)--In the 1970s, Transmission Control Protocol/Internet Protocol (TCP/IP) was developed by ARPA to connect incompatible computers used by military suppliers and researchers. It is a set of protocols that are compatible with the ISO/OSI reference model. Today, TCP/IP is emerging as the protocol of choice for interconnecting LANs. And, it has achieved the promise of open systems as today's de facto standard for open networking.[7] Often referred to as the TCP/IP suite of protocols, the suite comprise a set of protocols that define a variety of network applications, for example, file transfer and virtual terminals. While NetWare has a dominant position in the LAN-server marketplace, TCP/IP is the de facto standard for internetworking between diverse computing systems. One needs to consider interoperability implications between the choices of TCP/IP protocol and NetWare's IPX/SPX communications environment to appreciate the magnitude of this problem. Repeaters--A repeater is used when a cable needs to be extended beyond its recommended maximum length. Because the signal becomes weakened the further it travels, a repeater is employed to amplify and retransmit the signal. Bridges--A bridge is a device that can link two or more LANs to form one extended LAN that can span many miles. Bridges eliminate the distance restrictions and maximum-number-of-stations limit of LANs In addition, bridges act as packet filters and forward data that is intended only for remote LANs. Locally destined data remains local. Gateways--A module, or set of modules, that transforms the conventions of one network into the conventions of another (a gizmo that allows you connect one person's LAN with a different type of LAN). A gateway acts as a language translator and allows two disparate networks operating under different protocols to communicate. Routers--A router is used in internets (between networks) where more selective decision-making intelligence is required to select the most efficient path for the "data's" intended destination. It ensures faster traffic flow and can automatically provide for detours if a connection is broken along the path. Brouters--Synchronous line bridges, or brouters, forward packets from one LAN to another across bandwidths up to 2 Mbps. It is invisible to most protocols, so the entire extended LAN looks like one LAN. Hubs--To wrap up this section, a few words about hubs. Hubs range from simple, passive devices at the low-end to multifunction devices that include integrated bridging and routing at the high-end. To qualify as a hub, it must be capable of receiving a data signal and repeating it simultaneously to multiple wires through connections call "ports." Future Directions--The latest happenings in the internetworking area is what is going on with hubs. Price cutting is crating a buyer's market at the low end, while vendors focus on advanced features at the high end. Hewlett-Packard, 3Com, and Ungermann-Bass have cut prices such that cost per port is in the $100 to $200 range, with many offerings favoring the lower price. With 70 percent of the Fortune 500 companies using both Ethernet and token-ring networks, the vendors have responded with 10BaseT, low-cost hubs. Many vendors are incorporating bridging and routing modules into their hubs rather than require customers to by separate units. In terms of media, all major media choices are covered in today's product offerings. And, Simple Network Management Protocol (SNMP) has pretty much become the de facto standard for hub management. To describe its operation, in simple terms, SNMP agents capture device and network information and forward that data to conveniently located SNMP management stations for processing and display. Although it is greatly criticized as a light-weight protocol, it is easily implemented and requires the minimum resources to operate.[8] One of the hottest topics in today's LAN hub discussions is asynchronous transfer mode (ATM). Utilizing 53-byte fixed-cell relay transport technology, ATM is a transfer mode for switching and transmission that efficiently and flexibly organizes information into cells. It can be used in both LANs and WANs to provide high-speed (150 Mbps+) seamless integration of wide-area, campus, and desktop-LAN transport. But, for now ATM is a "future" technology. Over the next several years, expect Ethernet, token-ring, and FDDI to continue to dominate communications to the network users. X. CLOSING THOUGHTS The economic proof of the value of adopting and sticking to a certain LAN architecture is desirable but often difficult to illustrate. Typically, each campus unit seeks to install a network at the lowest possible cost. However, the sum of these unit costs often add up to a sum greater than the whole. If we end up with separate and not interoperable or adaptable LANs, the campus can lose out. "LANarchy" costs big bucks through lost opportunities. In closing, let us consider, "What makes networking successful?" There is downsizing, restructuring, and destructing going on everywhere. One thing is constant--people make systems work! First, no matter where "networking" is located in your organization, one needs to give the networking techie the executive clout to carry out this important function. Secondly, the more direct the line from that networking guru to the organization's top technologist or manager, the greater the possibility of successful networking. Nationally, there are over one hundred network users for every technical support person. And, when we think of their typical day, most of their time putting out "fires" and the rest of the catching their breaths. Operating in crisis mode, we need to help the networking staff to make time to grow and develop their skills and abilities. Unless we help them grow in breadth and depth, job hopping will occur. One day, we might just develop structure and positions so networkers will have normal patterns of promotion and career-pathing. We are all too familiar with the saying that can be adapted to our networking staff. "Techies do not necessarily managers make." So, as we work to develop good networks, let us adopt the slogan--"support your local techie!" People DO make a difference! NOTES [1] John F. Akers, President of IBM, Communications (Chicago: Time-Life Books, 1986), p. 8. [2] Stanford H. Rowe, II, Business Telecommunications, 2nd ed., (New York: Macmillian Publishing Company, 1991), p. 365. [3] Gary A. Howard & Frank X. Mara, "Design a Copper Network for PDS and LANs Using UTP," Cabling Business, October 1992, p.10. [4] Lynda Radosevich, "FDDI Over Copper Will Shake Down Ethernet," Computerworld, October 26, 1992, p. 50. [5] Kimberly Patch, "Digital's New Path for Pathworks," Datamation, June 1, 1992, pp. 73-76. [6] Caryn Gillooly, "Microsoft Marches Into Peer Net Market," Network World, November 2, 1992. [7] Marshall T. Rose, "Network Management is Simple: You Just Need the 'Right' Framework!" Integrated Network Management, II, (New York: Elsevier Science Publishers, 1991), pp. 9-23. [8] Salvatore Salamone, "The Hubbub About Hubs," Network World, June 1, 1992, pp. 47-50.