Fidonet: Technology, Tools, and History

FIDONET: TECHNOLOGY, TOOLS, AND HISTORY

sparse); and node is the particular Within a local network (e.g., city), host within the local network. The nodes usually exchange email di- addressing scheme may be extended rectly with one another. In those cit- to accommodate points which are ies where phone tariff zones divide power users who reduce their con- the city, local hubs are used to con- he public FidoNet consists of nect time by using private (i.e., un- centrate intracity traffic to reduce over 20,000 nodes which listed) nodes to exchange email and costs. move email and enews over enews with public nodes. Thus, the Each local network has one node the public telephone net- extended addressing scheme is with an alias of node 0 (i.e., zone:neff work using a unique proto- zone:net/node, point. 0) which is known as the inbound host. col and data format. As the The FidoNet nodelist, a list of all By default, all mail from outside the Tinitial implementations were written nodes in the public FidoNet network, local net is delivered to the inbound for MS-DOS, DOS-based hosts are is automatically updated and distrib- host to be distributed within the local still the vast majority of the network. uted weekly. This list contains the network. Thus, a node in New York But semiformal specifications for the actual data telephone number of may deliver all mail to San Francisco data formats and protocols have fa- each host, as well as the geographic with a single telephone call, as op- cilitated implementations for Unix, location and name of the system opposed to a call for every SF node for Apples from the//to the Macintosh, erator (sysop). Every city's local net- which it has mail. While each node is CP/M, MVS, the Tandy CoCo, and work maintains its local data and responsible for sending its own mail many other platforms. sends those data to a regional coordi- (as FidoNet is financed by users), As FidoNet is almost entirely fi- nator who, in turn, sends the region's some local networks cooperate suffi- nanced by private individuals, mini- aggregated data to a continental co- ciently to provide an outbound host to mization of modem/telephone time ordinator. The continental coordina- concentrate all mail destined for out- has been the principal driving force tors exchange their data, and create a side the city. behind any design of the data trans- list of differences between the cur- Each of the present six zones (con- fer protocols. The original imple- rent week's data and that of the pre- tinents) has a unique host which pro- mentations used an inefficient vious week. This nodediff is then dis- vides interzone email routing. These xmodem-based transport, a nonwin- tributed back down the hierarchy all zonegates have alias addresses of the dowed ACK/NAK protocol with 128- the way to each individual node in form orig-zone:orig-zone/dest-zone. For byte packets. Although rarely used in the network. example, the gate from North Amer- practice today, this protocol remains As all modem phone numbers are ica (zone 1) to Oceania (zone 3) has codified as the minimal basic stan- published in the nodelist, point-to- an addressing alias of the form 1 : 1/3. dard implementation, since it is triv- point transfers are always possible. Hence, a node in North America ial to code. Almost all current imple- But, as store-and-forward capabili- may save the cost of an interconti- mentations offer an optional suite of ties are specified in the basic stan- nental call to Australia by sending quite efficient zmodem-based dards, email tends to be routed the message to 1:1/3, which will in streaming transport protocols which through a worldwide hierarchic to- turn send it to 3:3/1, which will see are ACK-less, only NAKing in case of pology and enews via a worldwide ad that it is delivered within Australia. error. It is interesting to contrast this hoc, but generally geographically hi- Since November 1991, an experi- push for efficiency with uucp's prof- erarchic, acyclic graph. mental system has been using the ligate G protocol and the Internet's Internet to transport mail and enews SMTP and NNTP protocols. TOpology between Europe and North America. Addressing within FidoNet is Power users run points that may con- The data are moved directly between numeric with a bit of punctuation nect to only their respective host the zonegates via IP (i.e., not gated and specifies a particular node in the nodes to receive and deliver their between data formats) courtesy of administrative hierarchy. Addresses email and enews. As they are not in RIPE and EUnet. This saves FidoNet are of the form zone:net~node where the public nodelist, points are not operators thousands of dollars a zone is one of the six continents considered to be official nodes in the month. Since late in 1992, this tun- (North America, Europe, Oceania, network and thus are not subject to neling of the Internet has been ex- Asia, or Africa); net is the city (or constraints of technology, national tended to Taiwan, Southern Africa, larger area if the node density is mail hour, and so forth. Chile, and other areas. This is done

COMHUiIICATIOH|OFTHIIACM August 1993/Vo1.36, No.8 3S th the explicit consent of the IP local basis in many cities as FidoNet tion and possibly a small fee to com- carriers involved, to whom FidoNet echomail. pletely open facilities allowing full owes a considerable debt of grati- Internetwork gateways have been use for the first-time caller. tude. used extensively by nongovernmen- Although no formal measure- tal organizations (NGOs) in Africa, as ments have been made, it has been Gateways to the Other well as by an ingenious transport be- estimated that the average FidoNet Networks tween the South African academic IP BBS has over 200 active users; half There are gateways between FidoNet network (UNINET-ZA) and the use enews, and 5% use private email. and the uucp network, and thereby Internet [4]. As not all FidoNet nodes have BBS the Internet. FidoNet is addressable access, we can estimate that on the from the Internet DNS universe via Users order of 2 million FidoNet users read the DNS ~,one fidonet.org. A FidoNet FidoNet has currently over 20,000 or write enews, and approximately node, for .example, 1:105/42, has the distinct nodes worldwide. Although 200,000 of these use private email. domain name f6.nlO5.zlfidonet.org. FidoNet started in North America, Gating is done almost exclusively via by 1985 there were systems in Eu- History the uucp network. The IvlX forward- rope, very soon followed by systems In 1984, Tom Jennings wished to ers for thefidonet.org zone are set up on the other continents. Currently, move messages from his MS-DOS- so that there is default forwarding about 59% of the publicly listed based Fido 1 BBS to that of a friend, for all FidoNet hosts should there be nodes are in North America, 30% in John Madill. As Jennings was the no gateway which is local to the tar- Europe, 4% in Australia and New author of the Fido BBS, he was able get host. Zealand (Oceania), and 7% in Asia, to quickly modify it to extract mes- The correct RFC822 address for Latin America, and Africa. sages from a specially designated a FidoNet power user at point FidoNet technology is also used local message base and queue them zo:ne/no.po is [email protected]. privately within large corporations, for sending to the remote BBS. As FIDONET.ORG, for example, public institutions, and NGOs. While telephone rates are much lower in the scale of the private use of the middle of the night, he wrote a [email protected] zl .fidonet.org FidoNet is not known, it is estimated separate external program to run And, as points are optional in to be at least as large as the public this email transfer for one desig- FidoNet, Jane User at the BBS user at network. It is known to be used in nated hour to exchange mail with the node zone:net~node is user@Fnode. companies such as AT&T, Georgia other node. Nnet.Zzone.FIDONET.Ot'G, for ex- Pacific, and the Canadian Post Of- This soon grew to more nodes, ample, rice, among others. It is heavily used reaching 200 by early 1985. The nodelist, a list of all known active [email protected] ~donet.org by NGOs in Africa. While hobbyists and public BBSs nodes, was developed as a distributed The UFGATE package, which allows predominate the North American external file and was initially main- an MS-DOS-based FidoNet node to FidoNet, perhaps half of the public tained by Jennings. The reserved simulate a uucp host, gates both systems in Europe are subsidized by mail transfer hour became enshrined email and enews. This package made small to medium-scale businesses. In as zone mail hour and is preserved gating fairly popular by 1987. More Africa, there is very serious use by today despite current technology recently, other DOS packages have NGOs and poorly funded academic being capable of intermixing mail provided similar features. RFmail, a institutions. Within North America, transfer and BBS access. complete FidoNet implementation there is growing use within the With the porting of FidoNet to the which runs on Unix SysV and Xenix, school systems thanks to the spread- DEC Rainbow, FidoNet BBSs be- includes gateware to transform being K12Net [5]. came quite popular with the DEC tween FidoNet message format and While the original FidoNet sys- Users Group in St. Louis, Missouri. that of the uucp/Internet. tems were fully integrated within Ken Kaplan and Ben Baker were Currently, there are approxi- bulletin board systems, FidoNet mail- particularly active and started the mately one hundred gateway sys- only systems are now a noticeable first FidoNet newsletter. As the tems, most of them in North Amer- portion of the public network. These nodelist approached 100 members, ica. AsMe from tile expected provide the owner a facility similar to Kaplan and Baker took over from internetwork email, there is consid- ham radio or a fax machine, but pro- Jennings its organization and main- erable gating of Usenet news to and vide no public access via dial-up. tenance. from FidoNet echomail conferences. Around the world, BBSs with As the nodelist passed the 200 A number of newsgroups are FidoNet capability provide the most mark, it became obvious that, for shared globally by FidoNet and the publicly accessible and lowest-cost example, San Francisco had much Usenet, e.g., FidoNet',; MODULA-2 email and enews service today. While daily traffic for St. Louis and vice echomail conference is Usenet's most BBSs are only usable by a single versa, and dozens of telephone calls comp.lang.modula2, and FidoNet's dial-up caller at a time, others run were being placed to all the various K12__Net conferences are the Usenet's multiline systems ranging from two IThe Fido BBS was developed on a machine k12.* hierarchy. Usenet newsgroups to 20 lines. Public access require- which was both slow and cumbersome, like the are also made available on a purely ments vary from formal user valida- dog named Fido, hence the name.

3• August 1993/Vo1.36, No.8 COImlPIUNICATIONS OFTIIE ACN nodes in each city. As calls within a began in 1986, with the publication (you may find this site generally use- U.S. city are generally inexpensive, of FSC-0001 describing the then- ful for acquiring FidoNet supplies, but calls between cities are not, it extant xmodem-based protocol suite such as documentation, tools, seemed obvious to concentrate the and the basic data formats [3]. This gateware). intercity traffic into one call per was shortly followed by a description FTS-0001 describes the original- night. Tt/erefore, what had been a of the nodelist in FSC-0002 [1]. A message data formats, session proto- simple linear nodelist was broken FidoNet Standards Committee (now cols, and link layer protocols for into a structure of city segments FTSC) was formed in 1986 by the FidoNet as it was originally devel- transforming the FidoNet address then-active software authors, chaired oped by Tom Jennings. The ability notation from node to net/node. by a nonauthor. The FTSC collects for a node to obey this standard is In late 1986, it became obvious and publishes documents called mandatory if it wishes to be listed that an analogous problem existed FSCs, which are similar to the IETF's within the public FidoNet, although between the continents. At the same RFCs. Those which are voted as for- the vast majority of connections now time, the idea emerged of power mal standards are known as FTS use the far more efficient FTS-0006 users, or points, who could use documents. suite. Data transfer uses xmodem FidoNet data formats and transport There are approximately 80 FSC and a variant called Telink, 128-byte protocols (as opposed to BBS inter- documents at this time and five offi- block ACK/NAK protocols, neither faces) to send and receive their mail cial FTS standards, Some of the most of which is streaming, bidirectional, and enews. So, at a FidoNet Stan- interesting are depicted in Table 2. or windowing, and which discrimi- dards Committee meeting in October The current document set is kept on nate between email and file transfer 1986, the nodelist was redesigned as many FidoNet nodes and is available at the session and data transfer level. a four-level hierarchy of zone (conti- via ftp on the internet as Midfile restart recovery is also ab- nent), net, node, and point, with the sent. address becoming ftp.psg.com:~/publfidonetlstdsl* zone:net/node.point, The FTS-0006 session and link as it remains today. layer protocols [2] were developed by The rate of growth of FidoNet Wynn Wagner and Vince Perriello in seems typical of electronic networks Table 1: 1987 to overcome the serious ineffi- in the last decade. The approximate ciency of FTS-0001. The default data number of nodes at the end of the link layer described uses zmodem, a year is illustrated in Table 1. At pres- very efficient streaming, windowing, ent, the registered public FidoNet is 1984 100 and ACK-less (NAK only on failure) considerably larger than Bitnet and protocol designed by Chuck has recently passed the estimated size Forsberg. It also provides midfile of the registered part of the uucp i 1986 1,400 restart recovery. The YooHoo/2U2 network. session-level protocol provides for In February, 1986, Jeff Rush de- exchange of identification and au- veloped FidoNet's form of enews thorization data as well as allowing called echomail. As very few FidoNet 1988 4,000 negotiation of the link layer protocol. users were familiar with the Usenet, they were quite surprised at the pop- Common Software Components ularity and rate of growth of 1990 9,000 Like their uucp/Internet brethren, echomail. Within two weeks, an in- ...... FidoNet systems tend to have differ- ternational echomail conference, ii!000 ent components to act as user, MODULA-2, was propagated be- 1992 16,000 transfer/routing, and transport tween Europe, Australia, and North agents. While not all FidoNet imple- America, and today the daily volume mentations are composed identically, of compressed echomail is over eight on the whole the following concepts megabytes (MB). The social effects, both good and bad, of echomail on Tuble 2: the network parallel those of the Usenet. Although primitive experiments had been conducted earlier, in 1986 gateways between FidoNet and the uucp network, and hence the Inter- net, became sufficiently reliable for production use.

TeChnical Standards Technical standards development

COMMUNICATIOM| OF TIlil ACM August 1993/Vol.36, No.8 33 FidoNet has been owned and operated primarily by end users more than computerprofessionals. Therefore, social and political issues arose in FidONet far faster and more seriously than other network cultures.

and nomenclature are understood A Mailer is the session and link vide minimal-cost public access to throughout FidoNet. level transport layer which decides email. Two very basic features of A Bulletin Board Sys/.em (BBS) is when to make and accept FidoNet FidoNet encourage this. Every node often available and provides a mail calls to/from other nodes and pro- is self-sufficient, needing no support and news user agent (M/NUA) to vides everything needed to transport from other nodes to operate. But dial-up callers of the BBS, and it the email, enews, and files between more significant is that the nodelist often provides a console interface for FidoNet nodes. Mailers know about contains the modem telephone num- the system operator as well. As BBS modems and how to control them, ber of all nodes, allowing any node to M/NUAs must be usable by dial-up how to detect if an incoming call is a communicate with any other node users on unspecified terminals, the human BBS user as opposed to an without the aid or consent of techni- interfaces tend to be line oriented incoming FidoNet call, how to pass cal or political groups at any level. with rather primitive editing facili- humans through to a BBS, what This is in strong contrast to the uucp ties. Some BBS systems such as Fido times of day to place expensive but network, Bitnet, and the Internet. and Opus provide complete software time-dependent calls, and so forth. In 1985, the first FidoNet policy suites integrating all components Because the mailer provides the link document was published. It con- necessary to use FidoNet, while most level protocols, its characteristics de- cerned itself almost entirely with other BBSs require the addition of termine internode compatibility; technical procedural issues. It re- external components ~:o use them therefore a node is best known for quired a capability to send and re- with FidoNet. the mailer it runs. Hence a node ceive email, defined the national mail An Editor is a console M/NUA might be known as a Binkley node or hour as mandatory, delineated roles which is usually available for those a Fido node because it uses of the local network hubs and nodes which do not have a BBS, or BinkleyTerm or Fido as its mailer. nodelist coordinators, and stated where the system operator prefers a A Nodelist Compiler transforms the simple restrictions on routing of traf- different interface. A,; the system nodelist from the standard FTS-0005 fic through unsuspecting nodes. In console generally has known charac- distribution format to that needed by addition, it stated two social rules, a teristics, Editor M/NUAs tend to- the node's other software, (i.e., proscription against use of the net- ward screen-oriented, multicolor, mailer, BBS, editor, and/or packer). work for illegal purposes (e.g., pi- fancy interfaces, often with quite Aside from trivial differences in syn- rated software) and a statement of sophisticated editing capabilities. tax, more complex translations may FidoNet's basic social guideline: "Do A Packer or Scanner is analogous to be needed, (i.e., mailer software usu- not be excessively annoying, and do the mail/news transfer agent (M/ ally requires that telephone numbers not become excessively annoyed." NTA). It transforms the data to/from be transformed given local rules). In 1986 a well-intentioned but the internal (i.e., not :~tandardized) naive group formed the Interna- storage fi3rmat from/to the external Policy and Politics tional FidoNet Association, intend- FTS-0001/4 transmission format. In contrast to the uucp network or ing to promulgate the technology Packer M/NTAs also make routing the Internet, and due mostly to the and coordinate publication of the decisions,, usually based[ on data in a low cost of entry, from its earliest newsletter and other writings about local routing rule file. These local days, FidoNet has been owned and the network. Unfortunately, as routing rules tell the M/NTA what operated primarily by end users and FidoNet operators were far more routes to use for mail within the local hobbyists more than by computer socially oriented than their more city network, cost reduction routes professionals. Therefore, social and technical brethren in the other net- for mail within the zone, and any political issues arose in FidoNet far works, the formal organization of special routes for interzone mail. faster and more seriously than might IFNA tended to draw considerable The NTA portion use,; an echomail be expected by those raised in other political interest and attracted the rule base to decide which echomail network cultures. less constructive political elements of groups are to be exchanged with Tom Jennings intended FidoNet the FidoNet culture. The issue came which other nodes in the network. to be a cooperative anarchism to pro- to a head in 1989 with an attempt to

4 August 1993/Vol,36, No.8 IIIOMMUMICATIOM$ OF Tile lli¢lll ~J'J'~flffln~

load the IFNA board of directors Larry Landweb,er incited the devel- tion Networks]; Special-Purpose and pass a motion which explicitly opment of this article, and has been Application-Based Systems put IFNA in complete control of the the major force to include FidoNet General Terms: Design network. The motion was cleverly within the Internet community. I Additional Key Words and Phrases: forced into a netwide referendum and the networking community owe FidoNet (FidoNet's only global vote to date) a great debt to them. [] which required a majority of the net- About the Author: work assent to IFNA rule. The refer- References RANDY BUSH is a compiler netware, endum did not pass, and IFNA was 1. Baker, B. The distribution nodelist. tools hacker, and too often a software subsequently dissolved. FSC-0027. engineering manager. Residing in Port- 2. Becker, P. YOOHOO and YOOHOO/ The first written policy was pub- land, Oreg., he is currently a software 2U2: The Netmail handshake used by lished and adopted by informal con- architect at Olsen and Assoc., Zurich. He Opus-CBCS and other intelligent sent. Subsequently, three revisions of has been involved in the integration of FidoNet mail handling packages, FTS- appropriate networking technology in the FidoNet policy have been written 0006. developing world for over four years, and made operational by various, but 3. Bush, R. A basic FidoNet technical using FidoNet, UUCP, and TCP/IP. An- less democratic, procedures. The standard. FTS-0001. thor's Present Address: [email protected] current document, Policy-4, was 4. Guillarmod, F.J. From FidoNet to written by the regional nodelist coor- Internet: The evolution of a national dinators and has a large amount of network. In Proceedings of INET'92. social and political content enshrin- 1992. Permission to copy without fee all or part of this material is granted provided that the copies are not ing a hierarchy of coordinators: an 5. Murray, J. K12 Network:Global educa- tion through telecommunications. In made or distributed for direct commercialadvantage, International Coordinator (IC), a the ACM copyrightnotice and the title of the publi- Proceedings of 1NET'92. 1992. Zone Coordinator (ZC) on each con- cation and its date appear, and notice is give that copying is by permission of the Association for tinent, Regional Coordinators (RCs) CR Categories and Subject Descrip- Computing Machinery. To copy otherwise, or to in subdivisions of the continents, tors: C.2.1 [Computer-Communication republish, requires a fee and/or specificpermission. usually countries, and a Network Networks]: Network Architecture and Coordinator (NC) for each local net- Design; C.2.3 [Computer-Communiea- © ACM 0002-0782/93/0800-031 $1.50 work. As it was written by the self- anointed RCs, ZCs and the IC are elected by the RCs, and NCs are ap- pointed by the RCs. Although the document has caused considerable acrimony and is large and complex, it contains many useful operational guidelines, and is therefore generally observed. The amazing resilience of FidoNet's social and technical structure was made evident yet again in 1989-'90, when the RCs on many of the continents attempted to exert serious social control under the re- FACT #2: cently published Policy-4. While echomail provided quite high- bandwidth (albeit low content) com- ACM Member Services Department munication, and thus the political sit- 1515 Broadway NY~ NY 10036 uation could be openly debated, the TFfLEPHONE." 1. 212. 626. 0500/ power structure's inability to restrict FAX." L212.944.1318 node-to-node communication pre- EMAIL: [email protected] vented any real control from being FACT #3: effected. A fair number of RCs and NCs were forced to resign, and the others have since taken more passive and facilitative roles. PAX: 1.212.944.1318 EMAIL: [email protected] Acknowledgments For pre-paid and purchase orders mail your order and payment to: ACM Order Department Tom Jennings not only designed and PO Box 12114 developed FidoNet, but has been a Church St. Station NY, NY 10257 USA friend as well as reviewer. Ishida For SIGGRAPH Video Review call First Priority at 1.800.523.5503 or 1.708.250.0807; Haruhisa provided encouragement, fax: 1.70&250.0038. incentive, and very helpful reviews.

¢OMMUNICATIOHS OF THE ACM August 1993/Vol.36, No.8 3S