An Overview of Networking for Physicians and Problems of Network Consulting in Remote Areas EBERHARD W. LISSE Department of Obstetrics and Gynecology Katutura State Hospital Windhoek, Namibia In 1987 I graduated from the medical school of the Technical University in Aachen, Germany, where I had been introduced to computer networking. Since 1988 I have been working in Namibia as a medical practitioner. I spent two years in the northern rural area of Ovamboland, six months in the coastal town Swakopmund, and since then have been working in the capital Windhoek. The University of Namibia has a small Department of Computer Science with which I have been working to develop and install a computer network that connects to the Internet. This paper provides an introduction to computer networking with particular regard to implementations in remote areas. NAMIBIA
Namibia is located on the western side of the horn of Africa and became independent in 1989 after having been administered by South Africa as South West Africa since the First World War. It has a territory of about 318,000 sq miles and, according to the preliminary figures of the 1990 census, about 1.4 million inhabitants.’ About half of the population lives in an area of less than 10% of the country (Windhoek and Ovamboland in the north). Before independence the population was divided along ethnic lines into so-called population groups, namely, whites, coloreds, and blacks, who were subdivided according to tribal lines. Education and health, for example, were assigned as “own affairs” to the representative authorities created for these groups, but funding for these groups was not assigned proportionally to the size of the groups. The homeland government of Ovamboland, for example, maintained about 40 clinics staffed by registered nurses and midwives with primary health care training, seven district hospitals (with 80 to 200 beds) of which only two were staffed with doctors, and a regional hospital with 800 beds in Oshakati.* Outside the homelands the Department of National Health contracted private general practitioners to be District Surgeons on a part-time (session) basis to run small district hospitals and supervise the primary health care clinics. It also maintained the central .Windhoek State Hospital as the main referral center. The Administration for Whites maintained separate facilities even if it meant having two hospitals in the same town. Since independence all affairs have reverted to the central government, and the fragmentation and duplication of services have been abandoned. Health care was and is available for a nominal charge to “state patients” earning below a monthly income of 500R (US $150) for single and l000R for married patients. Private general practitioners and specialists enjoy hospital privileges. There is an agreement with the 19
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University of Stellenbosch in Cape Town, Republic of South Africa (RSA), for referral of patients who are in need of specialized care not available in Namibia, such as cardiac surgery. Each year about 25 medical graduates from the RSA do their internship in Namibia, the majority in the Windhoek State Hospital.
COMPUTER NETWORKING Electronic Mail
Computer networking has developed within the last two decades, with important advances having been made in the last five years. The early mainframes were batch oriented. Each job consisted of “job cards” containing operating system commands, for example, JCL on IBM mainframes, the program in FORTRAN, COBOL or PL/I; and data cards containing the input to the program. These stacks of cards would then be fed into card readers, and the operating system would execute one job after the other. The programs would be compiled each time and executed on the data cards. The output usually resulted in varying numbers of printouts handed back with the cards. With the introduction of time-sharing operating systems (notably UNIX and its derivatives, VMS and VM/CMS),3 the users could now work on terminals and write their programs with more or less comfortable editors. Each user had his own disk space where he could keep files. Once programs worked they could be stored in executable form to be run without the compiling/linking steps. Because several people were sharing the same comfortable computer, ways to communicate with each other came into demand. On the UNIX system it was implemented in a simple but effective way by developing programs that would allow the users to compose messages which then would be stored in a central location in files called mailboxes that were only readable by the addressee (owner). These mail programs were installed in such a way that they afforded privileges to write to those files even if the sender of the mail did not have these privileges normally. A similar program was developed early on to write to other users’ terminals, also by way of special privileges awarded to the program rather than the user using it. The original programs that form part of the UNIX operating system (mail, write) are quite simple but sophisticated programs (efm,talk) and are available free of charge for almost all varieties of UNIX. VMS and VM/CMS have similar features.
UUCP (Unir-to-Unir-Copy) UNIX included early on software to connect to other UNIX systems. A special program uucico works in connection with a modulator/demodulator (modem) connected to a telephone, dialing the number of the neighboring computer that also has a modem installed which accepts incoming calls. A normal login sequence is initiated where the user-id and the password are transmitted as for any normal user; then the same special program is started on the other side. The two programs synchronize and exchange files that are waiting in queues destined for the other system. Even if the two computers are connected via direct (permanent) lines, UUCP only allows the transfer of files by “store and forward.” Therefore, for each mail message a special command file must also be transferred, which is then rcad by another program uuqr executed after the transfer session is finished. u q t feeds the mail messages into a mail transport program (mail) for either delivery (append-
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ing) to the addressee’s mailbox(-file) or moving it into a queue for further transport to another computer. This concept of “store and forward” also allows execution of programs on the remote host by way of transferring command files that are then executed on the remote system, if permitted. Implementations of UUCP became available as source code free of charge for MS-DOS4 and for UNIX.
TCP/tP (Transmission Control Protocolllnternet Protocol) Recently the TCP/IP protocol became widely implemented. It is a layered suite of protocols suited for use on top of ethernet and other local area network (LAN) circuits. Ethernet is a proprietary physical network that acts as a broadcast medium sending information in packets. Every machine on the network sees every packet even if it is destined for another machine. Each node (ethernet controller) has a unique address and should pay attention only to packets with its own address in the destination header. The IP protocol layered onto ethernct is concerned with getting datagrams to the correct destination, primarily by adding routing information to the packets. T C P provides the actual networking services such as keeping track of what has been sent, error chccking, splitting large files into datagrams (packets) and reassembling them on the other end. It interfaces with the applications on both sides in a manner transparent to the user. TCP/IP requires permanent circuits and thus offers realtime services such as electronic mail, file transfer, network database services, time services, remote printing, remote login, remote job execution, and real-time on-line communication with users on other computcrs. TCP/IP was developed by researchers of the ARPAnet, but is used worldwide on implementations for almost all operating systems including MS-DOS. Some implcmentations arc available free of charge. There arc implementations for serial lines and over special dial-up modems.
Other Networking Protocols VMS and VM/CMS use quite comfortable proprietary protocols for remote job cxccution, file transfer, mail, and, because they are run over permanent lines, also real-time on-line communication with users on other computers.
REQUIREMENTS
Hardware Basically, any two (or more) computer systems for which implementations of networking software exist can be connected. However, if network support is to be added onto cxisting systems occasionally vendor-specific hardware and software for the remotc centers are required. Any UNIX variant that can be used for UUCP as the load on the system imposed by the networking software is usually of short duration. Because T C P / I P is a real-time network and very comfortable for the users, the load is much higher. A powerful system with a 80386’ CPU, 4MB RAM, 120MB disk, a high resolution
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graphics card and monitor was quoted in Windhoek in early 1992 at about R6000. This is the equivalent of about US $2000 and approximately one-quarter of the price of a small car sold in Namibia. A typical UNIX graphics (RISC) workstation was offered locally for about R60,000 ($20,000) at the time of writing this paper. A high-speed modem (v32bis/v42) was quoted at R7500, whereas slower modems cost below R l W . Ethernet cards were quoted at around R1000. An uninterruptible power supply was quoted at R2000. An interesting aside is mentioned by Korpela6 who installed a medical record system at Obafemi Awolowo University Hospital, Ile-Ife, Nigeria in 1989 on a 80286 MS-DOS machine running a MUMPS-based medical records system, which originated from the Veterans Administration. It had two terminals, a large hard disk, and a tape drive. The costs for hardware were equivalent to two locally manufactured cars. Infrastructure
For an UUCP network the electricity supply must be reasonably stable but not necessarily continuous 24 hours per day. An Uninterruptible Power Supply (UPS) is essential to allow shutdown of the system in an orderly manner so as not to lose data in the event of a power failure. A telephone system with reasonable line quality and automatic exchange is required. Too much noise over the telephone lines will cause errors which will cause repeat transmissions. For TCP/IP the requirements are stricter. A stable, continuous, and uninterruptible power supply and a direct (leased) line to the neighboring computer must be available. A leased line was quoted by the Namibian Post Office at R3 per km per month. SopWare
Operating System An operating system is required on every computer to interact with the users, programs, and devices. It is also used to perform system administration functions and to maintain the integrity of data, etc. For the widely spread Intel range of processors MS-DOS is mainly used. It provides a single user, single tasking operating system for which add-on products exist to perform limited multitasking. UNIX and its derivatives are in very wide use. Versions of this multiuser, multitasking operating system exist for almost every computer brand. For the Intel processors several versions are available for less than $100 or totally free of charge (public domain) in varying states of completeness (Coherent? Mink, Linux, BSD, and Mach). Several commercial versions are quoted for less than $1000. Proprietary operating systems are usually bundled with the hardware as a package, and separate prices were not available.
Applications An immense range of commercial applications, programming tools, and free public domain software is available for MS-DOS, the latter often archived on computers connected to the computer networks?
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The following are required to connect a personal computer under MS-DOS to a network. UUCP. I use the above-mentioned implementation U U P Cwhich ,~ is available via the Internet from several software archives on an 80286. It includes all programs needed to dial up the remote computer via a modem connected to the serial port and to transfer files, mail and execute programs. It works best as a so-called leaf node where only one connection to a central backbone exists but can perform all routing functions of the original UUCP suite. The programs are manually started, but scheduling systems can easily be devised. UUPCincludes a mail program the user needs to compose messages; however, several compatible, more comfortable mail programs are available in the archives. There are at least two commercial UUCP versions for MS-DOS and at least two other public domain versions available. TCPIIP. The permanent connection to the network requires at least some programs (drivers) to be permanently loaded, thus reducing the availability of memory. At least two implementations in the public domain exist as well as several commercial ones. UNIX’s use of C as the programming language makes porting of programs written for one version to another comparatively easy. The application base is not as large as for MS-DOS, but programming tools and public domain software are also available via the networks. UUCP is part of the UNIX system and enhancements are available from the network. The individual programs are started by a scheduling system at regular intervals. There is at least one implementation available in the public domain (taylor-uucp‘”). TCP/IP is available for most UNIX systems. These programs run in the background continuously, interacting with the users’ programs and with the network. At least one implementation is available in the public domain.
Administrative
For each computer a unique name must be chosen. The system managers of all computers one wants to connect to via UUCP must configure their systems to allow login. Routing databases are not an absolute necessity as the complete route can be specified, but are more comfortable for the users. If the network is to be connected to the Internet, it must be registered with the Network Information Center (NIC) at ([email protected]). NIC ensures that the network domain name is unique; it updates the central database as to how to route to the new network. If connected via TCP/IP, unique network numbers are assigned. One computer on the new network maintaining a database for the network’s computers will be pointed to by the central database. If connected via other means (UUCP, for example), the central database has a “mail exchanger” entry that points to the TCP/IP-connected computer to which the new network connects via UUCP. If a user on the Internet wants to send mail to the new network, the address is passed to TCP/IP which can query the databases for the addressee’s or the mail exchanger’s unique network number and then route the mail. If a user on the new network wants to send mail to the Internet, it is forwarded to the mail exchanger which can resolve the addresses via queries of the central and regional databases.
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SuppoH
System Administration
Personal computers under MS-DOS can usually be run by anyone with the help of manuals or literature. However, experience is quite helpful. Installation of the uuPC package requires some knowledge of the network to which it is being connected and of the UUCP network itself. It can be installed within an hour especially if only one connection to a central backbone computer is needed. Once the basic system works, new connections can be installed easily by entering information in plain text files compatible with the original UUCP system. TCP/IP installation requires less time because only the network card needs to be connected, the host name needs to be entered, and the drivers need to be installed so as to load automatically on switching on of the system. To run a UNIX system or any multiuser system per se requires significantly more experience. The configuration of the UUCP system is quite similar to MS-DOS. Entries must be made in configuration files for each system to connect to. TCP/IP requires installation of the controller card and installation of the drivers and programs, which is usually handled by software.
Maintenance A hardware and software maintenance contract is mandatory if reliability is essential in a network. In the widespread MS-DOS systems, faulty components can usually easily be exchanged, but to enter 1000 patients’ records per day after several days waiting for a spare part can be a difficult undertaking.
PITFALLS tnfreslructure
In Namibia all district hospitals have electricity. Most hospitals are connected to the main power supply which is maintained reasonably well. Some have their own generators but usually do not run them the whole day. Most rural clinics are connected to the main power supply; few do not have electricity at all. All regional hospitals have a stable power supply and a backup generator that engages automatically. During my stay in Oshakati I have used my computer without an UPS for two years. Especially in the rainy season the power fluctuated occasionally, but I experienced no damage to the system. In the bigger towns the power supply is excellent. There is little noticeable fluctuation and the hospitals have uninterruptible power circuits and generator support. The mainframe running in the central laboratory, for example, has been stable since its installation in 1989. The main roads are tarred and in excellent condition. Gravel roads are used for local traffic and are in good to satisfactory condition. All towns and most villages can be reached with a normal car. The telephone system in urban areas is on the level of those in developed countries. Not all rural areas have automatic exchanges yet. Recently an automatic exchange has been installed in Oshakati in Ovamboland, and an optical cable has been laid over which packet-switched data communication is possible. The post office offers local phone numbers for packet switching in several
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towns with very favorable rates for connections within Namibia and to the RSA. The post office uses rail transport internally, and it usually takes three to five days for letters between Windhoek and the periphery. It is however very reliable.
Hardware
At the University of Namibia an 80386 compatible system with a 4MB RAM and 200MB disk capacity running SCO-XENIX" is used for student training and was set up as the network backbone. It supports eight terminals via a communication extension board. It performed very well and could handle UUCP calls even when all terminals were being used. A locally manufactured v22/v22bis modem with cables was donated after some lobbying with a local computer dealer. The modem did not work with the communication extension board, which does not support all required pins of the RS-232C. This, however, is essential for the modem to work. The modem has an unpredictable tendency to stop functioning, requiring it to be manually reset. This problem was solved by installing a timer switch to manually reset the modem on a regular basis without human intervention. After this software-related problem was solvcd, the modem has been working flawlessly. Rhodes University in Grahamstown, RSA, which is the mail exchanger (quagga.RU.ac.ZA), dials the machine during the lower rate periods rcgularily, and the transfers over 3000 km work very well. Currently there are three personal computers running uuPC under MS-DOS installed on the network without UPS systems and with three different v22/v22bis modems. No other hardware problems have been experienced yet.
Software Configurutiori
Configuration of the UUCP system on the XENIX system is done basically by way of installation scripts. It requires, however, prior experience with the operating system per sc and study of the system manuals and configuration files that have several examples.
UUCP The modem used at the University of Namibia uses by default the characters XON/XOFF to start and stop transmission via its proprietary error control software. These charactcrs are then not passed t o the computer. Under one condition of operation the UUCP communication program would fail with a cryptic error message. Extensive testing did not find the cause of this error. Several messages about similar problems experienced on other systems appearing on the Internet's news system prompted a comment on the lost character. It then took little time to find a manual for the modem and a way to install UUCP on the system so as to configure the modem to turn off its error controller. No other problems were encountered.
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Enhancements
Several public domain programs were obtained off the networks as C source code and installed: elm is one of several comfortable mail user agents (MUA) to compose and read electronic mail messages. It requires a configuration program to be run before installation which adapts the program as closely to the system as possible. smai12.5 is a mail transfer agent. It works beween the MUA (elm) and the transport layer (UUCP) and translates the addresses entered by the user into routes via one of the systems to which the computer is directly connected. UUCP itself is not concerned with addressing; it only transfers files between two computers. There is a default entry for unknown networks that could have been set to our mail exchanger. pathalias creates a database for use by smail which resolves for each known computer or network the complete path. To avoid unnecessary telephone fees to our mail exchanger caused by spelling errors in network names, a list of all networks known to a gateway between the Internet and another major network was used to create the database. The default entry in the database was not set.
These programs have been running since November 1991 without any problems. Slrpport
The problems mentioned above required prior experience with the UNIX operating system and still took time to solve. The local software dealer donating the modem was very helpful and competent in solving the cable problems with the communication extension board, which nevertheless took several visits. They could not help us with the UUCP software/modem problem. Training can only be given in Windhoek. Consider the following example: Oshakati lies 750 km from Windhoek by road. By plane it is about three hours. The x-ray department in Oshakati State Hospital has a service contract with a Windhoek-based company that sends technicians by plane in case of failures. This of course is reflected in the costs of the service contract. Plans Referrals
Currently, elective referrals from the peripheral hospitals to Windhoek State Hospital are handled by phone and telefax to a booking office that keeps track of bed occupancy and liaises with the attending physicians via the ward sisters. Electronic mail is less prone to misunderstanding than the telephone, and typed referral letters would improve decision making by the attending physicians. Contact is being established with the University of Stellenbosch via the network. Few actual consultations have taken place yet, but preliminary results are promising. Central Laboratory
The central laboratory in Windhoek uses a mainframe with a proprietary operating system to which most analyzers are connected. The results are maintained
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in databases for on-line access and printouts. It is also used to type and print histology and cytology reports. It functions to the satisfaction of the laboratory. The printouts are transported by courier to the main hospital building in Windhoek or sent by mail or with the scheduled ambulance runs to the peripheral hospitals. Printouts of urgent results are then phoned to the wards or faxed to the peripheral hospitals. This is an improvement over having to retype the results into a telex machine, but has the disadvantage that human intervention is still required. Thus far it has not been possible to connect terminals in the main hospital building because of lack of funds for modems. To feed results into a database on another computer will require significant funds for programming and networking hardware. Epidemiology Recently the Ministry of Health and Social Services has implemented a Health Information System. Data is entered onto counting sheets daily in all hospitals and clinics, and in intervals summary sheets are sent to the Ministry. Data that are collected locally can readily be entered into databases locally. A suitable system could be EpiInfolZfrom the Centers for Disease Control in Atlanta, Georgia, which is freely available from the network archives. It combines ease of operation with graphics capabilities, compatibility with industry standard databases and mainframe statistical systems. It is a simple task to program it to feed data into UUPC,for cxample, on a periodic basis to be forwarded to the central database. Reports can be returned in the same manner.
CONCLUSION Computer networking in remote areas of developing countries is possible. The only absolute requirement is an automatic exchange telephone system. Inasmuch as cost is the major factor, the minimum configuration is an uninterruptible power system, any MS-DOS computer with even a small hard drive and a modem that can be obtained for about US $2000. The networking software can be obtained free of charge from the networks. High technology solutions are not advisable in the periphery. Too many projects have resulted in expensive donated equipment becoming inoperable because of lack of maintenance, spare parts, or manuals." However, ideally at least one central site in each country should have a TCP/IP connection to the Internet to enable fast access to databases, software archives, the network news system, and co-workers in other countries. This seems to me a task suited for international agencies (such as UNDP, UNICEF, or the EEC).
SUMMARY For computer networking the most suitable operating systems are UNIX or MS-DOS. As networking software UUCP and TCP/IP are most common. Hardware requirements are derived from the operating system and from the networking software. Low-cost solutions, for example, UUPC,a public domain version of UUCP, require only an 8088 processor and a 2400-baud modem. TCP/IP fares better with
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more powerful processors and requires permanent lines between the connecting computers. In developing countries the introduction of computer networks is hampered by several factors: lack of foreign exchange, price of hardware and software, unreliable electricity and telephone lines, lack of hardware and software support, large distances to the nearest center, and incompatibilities between existing systems and the network. Important aspects for clinical networking in developing countries include appointment scheduling in the referral hospitals, access to laboratory and pathology results from the central laboratory, and primary health care information such as epidemiologic data. Advanced systems, for example, for image processing, are not yet feasible in developing countries. NOTES AND REFERENCES 1. Namibia is approximately 39 times the size of the state of Massachusetts and has approximately 7 million inhabitants. 2. WIITHUHN,L. 1987. Annual Report of the Department of Health. 22-28. 3. UNIX is a trademark of AT&T; VMS, a trademark of Digital Equipment Corporation; and VMKMS, a trademark of International Business Machines Corporation. 4. MS-DOS is a trademark of Microsoft Corporation. 5. 80386 is a trademark of Intel Corporation. 6. KORPEIA,M. 1990. The Ife Project Report 1989. University of Kupio. Kupio. 7. Coherent is a trademark of the Mark Williams Company. 8. wsmr-simtel20.army.MIL or its mirror sites. 9. UUPCis maintained by Drew Derbyshire ([email protected]). 10. taylor-uucp is maintained by Ian Taylor ([email protected]). 11. XENIX is a trademark of Microsoft Corporation. 12. Epilnfo is maintained by Karl Brendel ([email protected]).
Namibia is located on the western side of the horn of Africa and became independent in 1989 after having been administered by South Africa as South West Africa since the First World War. It has a territory of about 318,000 sq miles and, according to the preliminary figures of the 1990 census, about 1.4 million inhabitants.’ About half of the population lives in an area of less than 10% of the country (Windhoek and Ovamboland in the north). Before independence the population was divided along ethnic lines into so-called population groups, namely, whites, coloreds, and blacks, who were subdivided according to tribal lines. Education and health, for example, were assigned as “own affairs” to the representative authorities created for these groups, but funding for these groups was not assigned proportionally to the size of the groups. The homeland government of Ovamboland, for example, maintained about 40 clinics staffed by registered nurses and midwives with primary health care training, seven district hospitals (with 80 to 200 beds) of which only two were staffed with doctors, and a regional hospital with 800 beds in Oshakati.* Outside the homelands the Department of National Health contracted private general practitioners to be District Surgeons on a part-time (session) basis to run small district hospitals and supervise the primary health care clinics. It also maintained the central .Windhoek State Hospital as the main referral center. The Administration for Whites maintained separate facilities even if it meant having two hospitals in the same town. Since independence all affairs have reverted to the central government, and the fragmentation and duplication of services have been abandoned. Health care was and is available for a nominal charge to “state patients” earning below a monthly income of 500R (US $150) for single and l000R for married patients. Private general practitioners and specialists enjoy hospital privileges. There is an agreement with the 19
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University of Stellenbosch in Cape Town, Republic of South Africa (RSA), for referral of patients who are in need of specialized care not available in Namibia, such as cardiac surgery. Each year about 25 medical graduates from the RSA do their internship in Namibia, the majority in the Windhoek State Hospital.
COMPUTER NETWORKING Electronic Mail
Computer networking has developed within the last two decades, with important advances having been made in the last five years. The early mainframes were batch oriented. Each job consisted of “job cards” containing operating system commands, for example, JCL on IBM mainframes, the program in FORTRAN, COBOL or PL/I; and data cards containing the input to the program. These stacks of cards would then be fed into card readers, and the operating system would execute one job after the other. The programs would be compiled each time and executed on the data cards. The output usually resulted in varying numbers of printouts handed back with the cards. With the introduction of time-sharing operating systems (notably UNIX and its derivatives, VMS and VM/CMS),3 the users could now work on terminals and write their programs with more or less comfortable editors. Each user had his own disk space where he could keep files. Once programs worked they could be stored in executable form to be run without the compiling/linking steps. Because several people were sharing the same comfortable computer, ways to communicate with each other came into demand. On the UNIX system it was implemented in a simple but effective way by developing programs that would allow the users to compose messages which then would be stored in a central location in files called mailboxes that were only readable by the addressee (owner). These mail programs were installed in such a way that they afforded privileges to write to those files even if the sender of the mail did not have these privileges normally. A similar program was developed early on to write to other users’ terminals, also by way of special privileges awarded to the program rather than the user using it. The original programs that form part of the UNIX operating system (mail, write) are quite simple but sophisticated programs (efm,talk) and are available free of charge for almost all varieties of UNIX. VMS and VM/CMS have similar features.
UUCP (Unir-to-Unir-Copy) UNIX included early on software to connect to other UNIX systems. A special program uucico works in connection with a modulator/demodulator (modem) connected to a telephone, dialing the number of the neighboring computer that also has a modem installed which accepts incoming calls. A normal login sequence is initiated where the user-id and the password are transmitted as for any normal user; then the same special program is started on the other side. The two programs synchronize and exchange files that are waiting in queues destined for the other system. Even if the two computers are connected via direct (permanent) lines, UUCP only allows the transfer of files by “store and forward.” Therefore, for each mail message a special command file must also be transferred, which is then rcad by another program uuqr executed after the transfer session is finished. u q t feeds the mail messages into a mail transport program (mail) for either delivery (append-
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ing) to the addressee’s mailbox(-file) or moving it into a queue for further transport to another computer. This concept of “store and forward” also allows execution of programs on the remote host by way of transferring command files that are then executed on the remote system, if permitted. Implementations of UUCP became available as source code free of charge for MS-DOS4 and for UNIX.
TCP/tP (Transmission Control Protocolllnternet Protocol) Recently the TCP/IP protocol became widely implemented. It is a layered suite of protocols suited for use on top of ethernet and other local area network (LAN) circuits. Ethernet is a proprietary physical network that acts as a broadcast medium sending information in packets. Every machine on the network sees every packet even if it is destined for another machine. Each node (ethernet controller) has a unique address and should pay attention only to packets with its own address in the destination header. The IP protocol layered onto ethernct is concerned with getting datagrams to the correct destination, primarily by adding routing information to the packets. T C P provides the actual networking services such as keeping track of what has been sent, error chccking, splitting large files into datagrams (packets) and reassembling them on the other end. It interfaces with the applications on both sides in a manner transparent to the user. TCP/IP requires permanent circuits and thus offers realtime services such as electronic mail, file transfer, network database services, time services, remote printing, remote login, remote job execution, and real-time on-line communication with users on other computcrs. TCP/IP was developed by researchers of the ARPAnet, but is used worldwide on implementations for almost all operating systems including MS-DOS. Some implcmentations arc available free of charge. There arc implementations for serial lines and over special dial-up modems.
Other Networking Protocols VMS and VM/CMS use quite comfortable proprietary protocols for remote job cxccution, file transfer, mail, and, because they are run over permanent lines, also real-time on-line communication with users on other computers.
REQUIREMENTS
Hardware Basically, any two (or more) computer systems for which implementations of networking software exist can be connected. However, if network support is to be added onto cxisting systems occasionally vendor-specific hardware and software for the remotc centers are required. Any UNIX variant that can be used for UUCP as the load on the system imposed by the networking software is usually of short duration. Because T C P / I P is a real-time network and very comfortable for the users, the load is much higher. A powerful system with a 80386’ CPU, 4MB RAM, 120MB disk, a high resolution
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graphics card and monitor was quoted in Windhoek in early 1992 at about R6000. This is the equivalent of about US $2000 and approximately one-quarter of the price of a small car sold in Namibia. A typical UNIX graphics (RISC) workstation was offered locally for about R60,000 ($20,000) at the time of writing this paper. A high-speed modem (v32bis/v42) was quoted at R7500, whereas slower modems cost below R l W . Ethernet cards were quoted at around R1000. An uninterruptible power supply was quoted at R2000. An interesting aside is mentioned by Korpela6 who installed a medical record system at Obafemi Awolowo University Hospital, Ile-Ife, Nigeria in 1989 on a 80286 MS-DOS machine running a MUMPS-based medical records system, which originated from the Veterans Administration. It had two terminals, a large hard disk, and a tape drive. The costs for hardware were equivalent to two locally manufactured cars. Infrastructure
For an UUCP network the electricity supply must be reasonably stable but not necessarily continuous 24 hours per day. An Uninterruptible Power Supply (UPS) is essential to allow shutdown of the system in an orderly manner so as not to lose data in the event of a power failure. A telephone system with reasonable line quality and automatic exchange is required. Too much noise over the telephone lines will cause errors which will cause repeat transmissions. For TCP/IP the requirements are stricter. A stable, continuous, and uninterruptible power supply and a direct (leased) line to the neighboring computer must be available. A leased line was quoted by the Namibian Post Office at R3 per km per month. SopWare
Operating System An operating system is required on every computer to interact with the users, programs, and devices. It is also used to perform system administration functions and to maintain the integrity of data, etc. For the widely spread Intel range of processors MS-DOS is mainly used. It provides a single user, single tasking operating system for which add-on products exist to perform limited multitasking. UNIX and its derivatives are in very wide use. Versions of this multiuser, multitasking operating system exist for almost every computer brand. For the Intel processors several versions are available for less than $100 or totally free of charge (public domain) in varying states of completeness (Coherent? Mink, Linux, BSD, and Mach). Several commercial versions are quoted for less than $1000. Proprietary operating systems are usually bundled with the hardware as a package, and separate prices were not available.
Applications An immense range of commercial applications, programming tools, and free public domain software is available for MS-DOS, the latter often archived on computers connected to the computer networks?
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The following are required to connect a personal computer under MS-DOS to a network. UUCP. I use the above-mentioned implementation U U P Cwhich ,~ is available via the Internet from several software archives on an 80286. It includes all programs needed to dial up the remote computer via a modem connected to the serial port and to transfer files, mail and execute programs. It works best as a so-called leaf node where only one connection to a central backbone exists but can perform all routing functions of the original UUCP suite. The programs are manually started, but scheduling systems can easily be devised. UUPCincludes a mail program the user needs to compose messages; however, several compatible, more comfortable mail programs are available in the archives. There are at least two commercial UUCP versions for MS-DOS and at least two other public domain versions available. TCPIIP. The permanent connection to the network requires at least some programs (drivers) to be permanently loaded, thus reducing the availability of memory. At least two implementations in the public domain exist as well as several commercial ones. UNIX’s use of C as the programming language makes porting of programs written for one version to another comparatively easy. The application base is not as large as for MS-DOS, but programming tools and public domain software are also available via the networks. UUCP is part of the UNIX system and enhancements are available from the network. The individual programs are started by a scheduling system at regular intervals. There is at least one implementation available in the public domain (taylor-uucp‘”). TCP/IP is available for most UNIX systems. These programs run in the background continuously, interacting with the users’ programs and with the network. At least one implementation is available in the public domain.
Administrative
For each computer a unique name must be chosen. The system managers of all computers one wants to connect to via UUCP must configure their systems to allow login. Routing databases are not an absolute necessity as the complete route can be specified, but are more comfortable for the users. If the network is to be connected to the Internet, it must be registered with the Network Information Center (NIC) at ([email protected]). NIC ensures that the network domain name is unique; it updates the central database as to how to route to the new network. If connected via TCP/IP, unique network numbers are assigned. One computer on the new network maintaining a database for the network’s computers will be pointed to by the central database. If connected via other means (UUCP, for example), the central database has a “mail exchanger” entry that points to the TCP/IP-connected computer to which the new network connects via UUCP. If a user on the Internet wants to send mail to the new network, the address is passed to TCP/IP which can query the databases for the addressee’s or the mail exchanger’s unique network number and then route the mail. If a user on the new network wants to send mail to the Internet, it is forwarded to the mail exchanger which can resolve the addresses via queries of the central and regional databases.
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SuppoH
System Administration
Personal computers under MS-DOS can usually be run by anyone with the help of manuals or literature. However, experience is quite helpful. Installation of the uuPC package requires some knowledge of the network to which it is being connected and of the UUCP network itself. It can be installed within an hour especially if only one connection to a central backbone computer is needed. Once the basic system works, new connections can be installed easily by entering information in plain text files compatible with the original UUCP system. TCP/IP installation requires less time because only the network card needs to be connected, the host name needs to be entered, and the drivers need to be installed so as to load automatically on switching on of the system. To run a UNIX system or any multiuser system per se requires significantly more experience. The configuration of the UUCP system is quite similar to MS-DOS. Entries must be made in configuration files for each system to connect to. TCP/IP requires installation of the controller card and installation of the drivers and programs, which is usually handled by software.
Maintenance A hardware and software maintenance contract is mandatory if reliability is essential in a network. In the widespread MS-DOS systems, faulty components can usually easily be exchanged, but to enter 1000 patients’ records per day after several days waiting for a spare part can be a difficult undertaking.
PITFALLS tnfreslructure
In Namibia all district hospitals have electricity. Most hospitals are connected to the main power supply which is maintained reasonably well. Some have their own generators but usually do not run them the whole day. Most rural clinics are connected to the main power supply; few do not have electricity at all. All regional hospitals have a stable power supply and a backup generator that engages automatically. During my stay in Oshakati I have used my computer without an UPS for two years. Especially in the rainy season the power fluctuated occasionally, but I experienced no damage to the system. In the bigger towns the power supply is excellent. There is little noticeable fluctuation and the hospitals have uninterruptible power circuits and generator support. The mainframe running in the central laboratory, for example, has been stable since its installation in 1989. The main roads are tarred and in excellent condition. Gravel roads are used for local traffic and are in good to satisfactory condition. All towns and most villages can be reached with a normal car. The telephone system in urban areas is on the level of those in developed countries. Not all rural areas have automatic exchanges yet. Recently an automatic exchange has been installed in Oshakati in Ovamboland, and an optical cable has been laid over which packet-switched data communication is possible. The post office offers local phone numbers for packet switching in several
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towns with very favorable rates for connections within Namibia and to the RSA. The post office uses rail transport internally, and it usually takes three to five days for letters between Windhoek and the periphery. It is however very reliable.
Hardware
At the University of Namibia an 80386 compatible system with a 4MB RAM and 200MB disk capacity running SCO-XENIX" is used for student training and was set up as the network backbone. It supports eight terminals via a communication extension board. It performed very well and could handle UUCP calls even when all terminals were being used. A locally manufactured v22/v22bis modem with cables was donated after some lobbying with a local computer dealer. The modem did not work with the communication extension board, which does not support all required pins of the RS-232C. This, however, is essential for the modem to work. The modem has an unpredictable tendency to stop functioning, requiring it to be manually reset. This problem was solved by installing a timer switch to manually reset the modem on a regular basis without human intervention. After this software-related problem was solvcd, the modem has been working flawlessly. Rhodes University in Grahamstown, RSA, which is the mail exchanger (quagga.RU.ac.ZA), dials the machine during the lower rate periods rcgularily, and the transfers over 3000 km work very well. Currently there are three personal computers running uuPC under MS-DOS installed on the network without UPS systems and with three different v22/v22bis modems. No other hardware problems have been experienced yet.
Software Configurutiori
Configuration of the UUCP system on the XENIX system is done basically by way of installation scripts. It requires, however, prior experience with the operating system per sc and study of the system manuals and configuration files that have several examples.
UUCP The modem used at the University of Namibia uses by default the characters XON/XOFF to start and stop transmission via its proprietary error control software. These charactcrs are then not passed t o the computer. Under one condition of operation the UUCP communication program would fail with a cryptic error message. Extensive testing did not find the cause of this error. Several messages about similar problems experienced on other systems appearing on the Internet's news system prompted a comment on the lost character. It then took little time to find a manual for the modem and a way to install UUCP on the system so as to configure the modem to turn off its error controller. No other problems were encountered.
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Enhancements
Several public domain programs were obtained off the networks as C source code and installed: elm is one of several comfortable mail user agents (MUA) to compose and read electronic mail messages. It requires a configuration program to be run before installation which adapts the program as closely to the system as possible. smai12.5 is a mail transfer agent. It works beween the MUA (elm) and the transport layer (UUCP) and translates the addresses entered by the user into routes via one of the systems to which the computer is directly connected. UUCP itself is not concerned with addressing; it only transfers files between two computers. There is a default entry for unknown networks that could have been set to our mail exchanger. pathalias creates a database for use by smail which resolves for each known computer or network the complete path. To avoid unnecessary telephone fees to our mail exchanger caused by spelling errors in network names, a list of all networks known to a gateway between the Internet and another major network was used to create the database. The default entry in the database was not set.
These programs have been running since November 1991 without any problems. Slrpport
The problems mentioned above required prior experience with the UNIX operating system and still took time to solve. The local software dealer donating the modem was very helpful and competent in solving the cable problems with the communication extension board, which nevertheless took several visits. They could not help us with the UUCP software/modem problem. Training can only be given in Windhoek. Consider the following example: Oshakati lies 750 km from Windhoek by road. By plane it is about three hours. The x-ray department in Oshakati State Hospital has a service contract with a Windhoek-based company that sends technicians by plane in case of failures. This of course is reflected in the costs of the service contract. Plans Referrals
Currently, elective referrals from the peripheral hospitals to Windhoek State Hospital are handled by phone and telefax to a booking office that keeps track of bed occupancy and liaises with the attending physicians via the ward sisters. Electronic mail is less prone to misunderstanding than the telephone, and typed referral letters would improve decision making by the attending physicians. Contact is being established with the University of Stellenbosch via the network. Few actual consultations have taken place yet, but preliminary results are promising. Central Laboratory
The central laboratory in Windhoek uses a mainframe with a proprietary operating system to which most analyzers are connected. The results are maintained
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in databases for on-line access and printouts. It is also used to type and print histology and cytology reports. It functions to the satisfaction of the laboratory. The printouts are transported by courier to the main hospital building in Windhoek or sent by mail or with the scheduled ambulance runs to the peripheral hospitals. Printouts of urgent results are then phoned to the wards or faxed to the peripheral hospitals. This is an improvement over having to retype the results into a telex machine, but has the disadvantage that human intervention is still required. Thus far it has not been possible to connect terminals in the main hospital building because of lack of funds for modems. To feed results into a database on another computer will require significant funds for programming and networking hardware. Epidemiology Recently the Ministry of Health and Social Services has implemented a Health Information System. Data is entered onto counting sheets daily in all hospitals and clinics, and in intervals summary sheets are sent to the Ministry. Data that are collected locally can readily be entered into databases locally. A suitable system could be EpiInfolZfrom the Centers for Disease Control in Atlanta, Georgia, which is freely available from the network archives. It combines ease of operation with graphics capabilities, compatibility with industry standard databases and mainframe statistical systems. It is a simple task to program it to feed data into UUPC,for cxample, on a periodic basis to be forwarded to the central database. Reports can be returned in the same manner.
CONCLUSION Computer networking in remote areas of developing countries is possible. The only absolute requirement is an automatic exchange telephone system. Inasmuch as cost is the major factor, the minimum configuration is an uninterruptible power system, any MS-DOS computer with even a small hard drive and a modem that can be obtained for about US $2000. The networking software can be obtained free of charge from the networks. High technology solutions are not advisable in the periphery. Too many projects have resulted in expensive donated equipment becoming inoperable because of lack of maintenance, spare parts, or manuals." However, ideally at least one central site in each country should have a TCP/IP connection to the Internet to enable fast access to databases, software archives, the network news system, and co-workers in other countries. This seems to me a task suited for international agencies (such as UNDP, UNICEF, or the EEC).
SUMMARY For computer networking the most suitable operating systems are UNIX or MS-DOS. As networking software UUCP and TCP/IP are most common. Hardware requirements are derived from the operating system and from the networking software. Low-cost solutions, for example, UUPC,a public domain version of UUCP, require only an 8088 processor and a 2400-baud modem. TCP/IP fares better with
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more powerful processors and requires permanent lines between the connecting computers. In developing countries the introduction of computer networks is hampered by several factors: lack of foreign exchange, price of hardware and software, unreliable electricity and telephone lines, lack of hardware and software support, large distances to the nearest center, and incompatibilities between existing systems and the network. Important aspects for clinical networking in developing countries include appointment scheduling in the referral hospitals, access to laboratory and pathology results from the central laboratory, and primary health care information such as epidemiologic data. Advanced systems, for example, for image processing, are not yet feasible in developing countries. NOTES AND REFERENCES 1. Namibia is approximately 39 times the size of the state of Massachusetts and has approximately 7 million inhabitants. 2. WIITHUHN,L. 1987. Annual Report of the Department of Health. 22-28. 3. UNIX is a trademark of AT&T; VMS, a trademark of Digital Equipment Corporation; and VMKMS, a trademark of International Business Machines Corporation. 4. MS-DOS is a trademark of Microsoft Corporation. 5. 80386 is a trademark of Intel Corporation. 6. KORPEIA,M. 1990. The Ife Project Report 1989. University of Kupio. Kupio. 7. Coherent is a trademark of the Mark Williams Company. 8. wsmr-simtel20.army.MIL or its mirror sites. 9. UUPCis maintained by Drew Derbyshire ([email protected]). 10. taylor-uucp is maintained by Ian Taylor ([email protected]). 11. XENIX is a trademark of Microsoft Corporation. 12. Epilnfo is maintained by Karl Brendel ([email protected]).
