FidoNet

FidoNet is an inter-connecting file and message transport system that was used by BBSes. The network still exists today, but is dwindling in size and organization due to the dying out of the systems it was developed to serve.

FidoNet was originally founded in 1984 by Tom Jennings of San Francisco, California as a means to network together BBS's that used his own "Fido" BBS software. Over time, other BBS software was independently adapted to support the relevant FidoNet protocols, and the network became a popular means for hobbyist computer users to communicate. FidoNet was non-commercial, and mostly popular amongst hobbyist computer users, many of them hackers and radio amateurs, before the the Internet became accessible and inexpensive.

1 Fidonet deployments
2 Technical structure
3 FidoNet availability
4 External links

Fidonet deployments

Although monolithic software, that encompassed all required functions in one package, was sometimes used, most FidoNet deployments were designed in a modular fashion. A typical deployment would involve several applications that would communicate through shared files and directories, and switch between each other through carefully designed scripts or batch files.

Mailer software was responsible for transferring files and messages between systems, as well as passing control to other applications, such as the BBS software, at appropriate times. The mailer would initially answer the phone and, if necessary, deal with incoming mail via FidoNet transfer protocols. When outgoing mail was waiting on the local system, the mailer software would attempt to send it from time to time. Due to the costs of toll calls, mailer software would usually allow its operator to configure the optimal times in which to attempt to send mail to other systems. If the mailer answered the phone and a human caller was detected rather than other mailer software, the mailer would exit, and pass control to the BBS software, which would then initialise for interaction with the user.

BBS software was used to interact with human callers to the system. As well as allowing dial-in users to use the system's message bases and write mail to others, locally or on other BBS's, that would later be routed and sent. BBS's would often allow users to exchange files, play games, and interact with other users in a variety of ways.

A scanner/tosser application would normally be invoked when a BBS user had entered a new fidonet message that needed to be sent, or when a mailer had received new mail to be imported into the local messages bases. This application would be responsible for handling the packaging of incoming and outgoing mail, moving it between the local system's message bases and the mailer's inbound and outbound directories. The scanner/tosser application would generally be responsible for basic routing information, determining which systems to forward mail to.

In later times, message readers that were independent of BBS software were also developed. Often the System Operator of a particular BBS would use a devoted message reader, rather than the BBS software itself, to read and write FidoNet and related messages. In some cases FidoNet nodes, or more often FidoNet points, had no public bulletin board attached, and existed only for the transfer of mail for the benefit of the node's operator.

The original Fido BBS software, and much other original fidonet-supporting software, is no longer in use. This is for several reasons, including problems related to the Y2K bug. In many cases, the original authors have left the BBS or shareware community, and the software, much of which was closed source, has been rendered abandonware. Alternative software had been designed to be interoperable with the same standards, however, and thus the network is still accessible.

Technical structure

FidoNet was historically designed to use modem-based dial-up access between bulletin board systems, and much of its policy and structure reflects this.

The FidoNet system officially refers only to transfer of "Netmail"—the individual private messages between bulletin boards—including the protocols and standards with which to support it. In practice, however, several other protocols for transferring other kinds of data were built on top of FidoNet, and they were often referred to as being part of it. The most popular of these was Echomail, comparable with Usenet-like newsgroups, however other systems allowed for the automated distrubution of files, transmission of data for inter-BBS games, and so on. Such protocols typically worked by using automated tools to package information, attach it to Netmail messages for transfer via FidoNet, and unpackage the information on receipt.

Routing of fidonet mail

In a theoretical situation, a node would normally forward messages to a hub. The hub, acting as a distribution point for mail, might then send the message to the Net Coordinator. From there it may be sent through a Regional Coordinator, or to some other system specifically set up for the function. Mail to other zones might be sent through a Zone Gate. For example, a message might follow the path:

1:170/918.42 (point) to 1:170/918 (node) to 1:170/900 (hub) to 1:170/0 (net coordinator) to 1:19/0 (region coordinator) to 1:1/0 (zone coordinator). From there, it gets distributed 'down stream' to the destination node(s).

Part of the objective behind the formation of local nets was to implement cost reduction plans by which all messages would be sent to one or more hubs or hosts in compressed form (ARC was nominally standard, PKZIP was also very widely used); one toll call could then be made during off-peak hours to exchange entire message-filled archives with an out-of-town uplink for further redistribution.

In practice, as FidoNet structure allowed for any node to connect directly to any other, node operators would sometimes form their own toll-calling arrangements on an ad-hoc basis, allowing for a balance between collective cost saving and timely delivery. For instance, of one node operator in a network offered to make regular toll calls to a particular system elsewhere, other operators might arrange to forward all of their mail destined for the remote system, and those near it, to the local volunteer.

This ad-hoc system was particularly popular with networks that were built on top of FidoNet. Echomail, for instance, often involved relatively large file transfers due to its popularity. If official FidoNet distrubutors refused to transfer Echomail due to additional toll charges, other node operators would sometimes volunteer. In such cases, echomail messages would be routed to the volunteers' systems instead.

As the FidoNet system was best adapted to an environment in which local telephone service was inexpensive and long-distance calls (or intercity data transfer via packet-switched networks) artificially costly, it has fared somewhat poorly in countries such as Japan (where local lines are expensive) and only been moderately successful in countries such as France where tolls on local calls and competition with Minitel or other data networks have traditionally limited its growth.

Geographic structure

Fidonet is politically organized into a tree structure, with different parts of the tree electing their respective coordinators. The Fidonet hierarchy consists of Zones, Regions, Networks, Nodes and Points broken down more-or-less geographically.

The highest level is the Zone which is largely continent based: Zone 1 is North America, Zone 2 is Europe, Zone 3 is Australia, Zone 4 is South America, Zone 5 is Africa and Zone 6 is Asia (excluding Russia, which is listed in Zone 2). Zone 7 was officially reserved for Antarctica, but was never used. Zones 8–4095 were often used for "othernets"; groupings of BBSes which used Fido-compatible software to carry their own independent message areas without being in any way controlled by FidoNet's political structure. Each zone is broken down into regions, which are broken down into nets, which consist of individual nodes.

Any given node may also support points. A "point" is a system that has a unique address derived from its parent node, but the point's owner is not an official member of FidoNet. Thus, the sysop who provided a fidonet feed to the point operator would officially be responsible for all mail originating from that point, as far as the remainder of the FidoNet network was concerned. Points were popular among users who did not operate BBS's, but wanted the independence of being able to operate their own message bases and mail reading software.

Fidonet addresses

Fidonet addresses explicitly consisted of a Zone number, a Network number (or region number), and a Node number. The Fidonet structure also allowed for semantic designation of region and hub status for particular nodes, but this status was not directly indicated by the address alone.

As an example, consider a node located in Tulsa, Oklahoma, USA whose assigned node number is 918: This is located in Zone 1 (North America), Region 19, Network 170. The full Fidonet address would be 1:170/918. Note, the region is for administrative purposes, not part of the address. Such a system may also support points: for a point assigned number 42 (by the Sysop of this node) the address would be 1:170/918.42.

Each Fidonet system would be required to maintain a nodelist of every other member system. Information on each node includes: name of the BBS, name of the Sysop, geographic location, telephone number, and software capabilities. This nodelist would be updated weekly, to avoid unwanted calls to 'phone numbers that'd been reassigned for voice use.

To accomplish the regular updates, coordinators of each network would maintain the list of systems in their local areas, and the lists would be forwarded back to the international coordinator via automated systems on a regular basis. The International Coordinator would then compile a new nodelist, and generate the list of changes (nodediff) to be distributed for node operators to apply to their existing nodelist.

Technical specifications

Fidonet contains several technical specifications for compatibility between systems. The most basic of all is FTS-0001, with which all fidonet systems were required to comply as a minimal requirement. FTS-0001 defines:

Handshaking – the protocols used by mailer software to identify each other and exchange meta information about the session.
Transfer protocol (XMODEM) – the protocols to be used for transferring files containing fidonet mail between systems.
Message format – the standard format for fidonet messages during the time which they were exchanged between systems.

Other specifications provide for echomail, different transfer protocols and handshake methods (e.g.: Yoohoo/Yoohoo2u2, EMSI), file compression, nodelist format, transfer over reliable connections such as the Internet (Binkp), and other aspects.

Zone mail hour

Since computer bulletin boards historically used the same telephone lines for transferring mail as were used for dial-in human users of the BBS, FidoNet policy dictated that at least one designated line of each FidoNet node must be available for accepting mail from other FidoNet nodes during a particular hour of each day.

"Zone Mail Hour", as it was named, varied depending on the geographic location of the BBS, and was designated to occur during the early morning. The exact hour varied depending on the time zone, and any BBS with only one telephone line was required to reject human callers. In practice, particularly in later times, most FidoNet systems tended to accept mail at any time of day when the phone line was not busy.

FidoNet availability

FidoNet usage has dropped a lot, but it is still particularly popular in Russia. Some of FidoNet's echomail conferences are available via gateways with the Usenet news hierarchy. There are also mail gates for exchanging messages between Internet and FidoNet. Widespread net abuse and e-mail spam on the Internet side has caused some gateways (such as the former 1:1/31 IEEE fidonet.org gateway) to become unusable or cease operation entirely.

As FidoNet dwindles in size, it has unfortunately also become a forum for personal attacks and cultural slurs. The political infrastructure of fidonet has also become fragmented, including a dispute over the position of its International Coordinator.

External links

Categories: Bulletin board systems | Computer networks