Section III
Computer Networks

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1. Why would I want to know about computer networks?
2. What are computer networks?
3. Can I connect to or send e-mail to networks beyond my host computer?
4. What does it mean if my e-mail service provider has a gateway?
5. What is UUCP?
6. What is Fidonet?
7. What are the advantages of off-line accounts in a developing country?
8. What are the limitations of off-line systems?
9. What is Packet Switching Network (PSN)?
10. What are the key features of PSN?
11. What are commercial networks?
12. What is the Internet?

The aim of this section is to help you understand and distinguish between the various computer communications services available in your area. We have attempted to highlight those features used by NGOs in developing countries. This section should help you make sense of the various descriptions of network services you may encounter.

What are computer networks?

The expression computer network can be confusing, because it can be used at different times to describe different aspects of the same thing. It can refer to a single host computer and the group of users who connect to it by telephone line. It can also refer to a group of host computers connected to each other via permanent links, using compatible software or protocols. For the purposes of this handbook, the term computer network refers to a single host computer and its group of users.

Networks can be classified according to either the services they offer users, or according to the community of users attracted by the service. There are four major categories of computer networks:

• networks linked interactively to the Internet, offering Internet tools ;
• off-line networks, such as Fidonet and UUCP;
• commercial service providers;
• Packet Switching Networks (PSN).

Can I connect to or send e-mail to networks beyond my host computer?

Yes. Nearly every e-mail service provider allows you to do this. Before signing up with an e-mail service, be sure you will be able to send e-mail to other networks. It may sometimes cost you extra to send and receive e-mail and information from networks other than your own.

What does it mean if my e-mail service provider has a gateway?

Gateways allow a network to connect to almost any other network (with the exception, perhaps, of a few isolated commercial networks). If your network has a gateway and nearly all do:

• you can send and receive messages to and from most networks;
• you can send requests for specific information from databases (if allowed), files and so on;
• you can have an Internet-style address;
• you can subscribe to mailing lists on specific topics, allowing dialogues with other users on a variety of networks.

• hobbyist networks like Fidonet;
• non-profit networks and those which provide services specifically to NGO communities (such as Alternex Brazil; Sangonet South Africa; Gluk Ukraine; GlasNet Russia; Chasque Uruguay; E-mail Centre Philippines; Laneta Mexico; Indialink India; Padisnet Ethiopia; MANGO Zimbabwe; Zangonet Zambia; Greennet UK; Antenna The Netherlands; IGC USA; Pegasus Australia; Web Canada);
• academic and research networks (including Internet, Global, Bitnet US and a few other countries, EARN European, Janet UK);
• commercial networks (Dialcom, CompuServe, Geonet, AT&T, MCI, Cgnet, and so on).

UUCP (Unix to Unix Copy Protocol) is a common and well-established system for exchanging e-mail and other information off-line. It is used fairly widely in developing countries. Networks using UUCP generally connect to Internet service providers to route their e-mail traffic.

What is Fidonet?

Fidonet is a computer network run by volunteers and hobbyists. It uses an e-mail system (with Fidonet-compatible software) which is quite common in developing countries. Groups working closely with NGOs in Africa, Asia and the Pacific have set up networks using this software.

Fidonet accounts are usually off-line. When these services are integrated with an interactive bulletin board system or computer conferencing system, they can also be accessed using standard on-line communication software (modems and software are discussed later in this handbook).

Fidonet networks have some useful features:

• they allow easy exchange of any language or character set, as long as the sender and receiver are both using compatible word-processing software;
• they transfer data very efficiently by compressing or packing information before sending;
• they have attracted a number of hobbyists to networking, creating a pool of local technicians capable of operating the networks; as a result, a wide variety of software and modules are available to access Fidonet.

Off-line networks:

• use methods of communicating (transfer protocols) which maximize the efficiency of poor quality phone lines;
• use software which is often inexpensive or free (usually for non-commercial use);
• use software which can be scheduled to send and receive e-mail automatically late at night when the telephone costs are lower. The call can be initiated by either the host computer or by the user; in the case of international calls, the call can be made by the computer in the country with the cheapest long distance rates.

• they cannot do anything that requires real-time interaction, such as accessing remote databases or using on-line Internet tools;
• they are not well-suited to one-to-many e-mail communications, especially international communications;
• on-line systems are faster, especially for sending e-mail, since a message is sent as soon as it is written; as a result, e-mail exchanges can take place nearly as rapidly as conversations.

Packet Switching Networks (also known as X.25 networks) work like public telephone systems, helping you connect to a remote host computer. They are data carriers that route data from one computer to another, nationally and internationally. PSNs are usually monopolies operated by the national telephone company. These networks tend to be used by the business community to transmit financial and accounting data. They are also used by individuals to connect to a network host computer long distance. They are usually of higher quality than normal phone lines. Some examples of PSNs are: RENPAC (Brazil), URUPAC (Uruguay), Eastnet (Philippines), CHINAPAC/CNPAC (China), KENPAC (Kenya), GPSS (India), THAIPAC (Thailand), VIETPAC (Vietnam), SKDP (Indonesia) and Sprintnet (worldwide).

What are the key features of PSN?

• PSNs are generally expensive to use, but there are some exceptions worth checking;
• in most cases PSNs provide carrier services, allowing users to connect to a remote service provider inside or outside the country; in some countries they provide e-mail and other services;
• accessing PSNs can involve making a local or intercity call;
• in most cases charges for PSN use cover registration costs, monthly subscription, and usage costs, which include the number of minutes you are connected plus the total volume of data transmitted during each session.

We can divide commercial networks into two types:

• e-mail service providers (such as CompuServe, AT&T Mail, MCI Mail, Geonet, Cgnet);
• database service providers (Dialog, Data-Star and so on).

Below are some general features of commercial networks:

• users come from a variety of backgrounds, and there is no emphasis on services for NGOs;
• they can be very expensive to use from most developing countries;
• they can be an excellent source of information on science, technology or government policies published in commercial journals;
• in many cases they are accessible through packet switching networks;
• commercial networks such as CompuServe are used very widely in industrialized countries, where they can be accessed at low cost.

The Internet is a computer network that joins other networks together: it is often referred to as a network of networks. It links networks in academic and government institutes, schools, libraries, corporations and those providing services to NGO communities. The Internet protocol (the software standard used to interconnect these networks) links many disparate and independent networks so that they appear as a single network to the users.

To sum up a complex subject, Internet provides:

• access to vast information resources;
• a way to connect to over 150 countries;
• a way to connect to over 30 million users worldwide;
• a cooperative environment for discussion, sharing of ideas and research;
• a relatively cheap link through which to exchange a large volume of information around the world;
• the possibility to connect to and search any other Internet computer based in different parts of the world, using tools or programs such as Gopher. Other tools which you might come across but which are not described in detail here include File Transfer Protocol, Archie, WAIS, Veronica and the World Wide Web.

Back to Section II: Computer Conferencing and Databases

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@t ease with email Copyright NGLS/UNCTAD, FES, 1995 UNCTAD/NGLS/55

Published by United Nations Non-Governmental Liaison Service (NGLS) and The Friedrich Ebert Foundation, New York