BBSs and Early Internet Access in Germany ========================================= :author: Harald Welte :copyright: 2017 by Harald Welte (License: CC-BY-SA) :backend: slidy :max-width: 45em == Circuit Switched Telephony * Telephony from 1876 until ~ 1988 * Analog voice circuit 300-3000 Hz * Dial-up connection between A and B party * Copper wires physically switched at intermediate telephone exchange * Voice signal possibly amplified in the path == Hardware * Telephone * Copper wire * Telephone Exchange == Accoustic Coupler * First devices to transmit bits as audible tones over telephone * User manually dialled phone number like voice call * After call was established, both sides put receiver into coupler image:images/accoustic_coupler.jpg[width="50%"] == Modems Automatization of the accoustic coupler * Avoid speaker/micrphone path * directly generate/receive tones on phone line * directly dial the phone number / answer the line image:images/Modems.jpg[width="50%",float="right"] == Modem Speeds / Standards [width="50%",options="header"] |====== |Standard|Rate (bps)|Year created |V.21 |300 |1962* |V.22 |1200 |1980* |V.22bis |2400 |1984* |V.32 |9600 |1984* |V.32bis |14400 |1991 |V.32ter |19200 |1993 |V.34 |28000 |1994 |V.34bis |33600 |1996 |V.90 |56000 |1998 |====== == BBSs What's a BBS? * Computer with Modem accepting incoming calls * offering interactive service to users who dial in == Content * bulletin boards / message boards * live chat with sysop (or other users in multi-line BBS) * multi-user games (text based!) * file areas / downloads * ASCII / ANSI artwork image:images/dosbox-telemate-login.png[width="50%"] == Technology/Software * Both sides: Computer + Modem * BBS Side ** BBS Software ** often extended by "doors" (external programs, think of CGI for web) * User Side ** Terminal Program (e.g. TELIX, Telemate for DOS) image:images/telemate.jpg[width="50%"] == The "BBS Protocol Stack" In the spirit of protocol stack diagrams... image:images/bbs-protocol_stack.svg[width="80%"] == Curiosity: Vector Graphics * BBSs were typically all Text, mostly ANSI CP437 charset * RIP (Remote Imaging Protocol) / RIPscrip introduced vector graphics ** RIPscrip introduced in 1992 (by TeleGrafix) *** Commands like ``!|w00001B0M10'' to draw vector graphics over Modem ** RIPterm as terminal program for EGA (640x350) image:images/Nouveau.png[] == Isolated BBSs To participate in bulletin/message boards * Users log in at different times * BBS is busy while a user is logged in * Multiple modems / phone lines is one (expensive) option to scale * Time limit per User (minutes/day) often used == Points / Offline Messages * Users don't read/write interactively during active modem call * Messages get written offline and compressed/batched during short call Advantages: * lower cost (shorter phone calls, metered!) * shorter connection per user * BBS can scale to more users this way image:images/xpmenu.gif[width="60%"] == BBS networks (store + forward) Idea: Replicate bulletin / message boards between independent BBSs, for * scalability in number of users * scalability in geographic scope ** most users will prefer least-expensive local calls to long-distance * efficient transport over long distance due to routing/forwarding of compressed batches == BBS network technology (examples) * FIDO (Netmail + Echomail) ** Othernets like TrekNet, GerNet using same FTN technology * Z-Netz (Mail + News) ** T-Netz, CL-Netz * UUCP (Usenet Mail + News) ** Often only way to access "Internet" before IP access was available * MausNet - Münster Apple User Service ** used by up to 120 BBSs in DE / AT / CH == Example: FIDOnet * Starts in 1984 with two BBSs * Initial limit of 250 nodes reached in 1985 * Hierarchic, Regoinal routing/Adressing introduced in 1986 ** Nodelist defines all nodes of the network + hierarchy * Addresses like "Harald Welte @ 2:2490/1343" * Up to 39,000 nodes in 1996, estimated 2 Million users world-wide == Example: Z-Netz * Started as Zerberus-Netz implemented in Zerberus Software * Later renamed to Z-Netz as the ZConnect protocol was implemented in other software ** Standards defined based on perceived complexity of RFCs and Usenet/UUCP * CrossPoint (DOS) most popular point software for ZConnect * Addresses like H.WELTE@SILVER, later H.WELTE@SILVER.zer == Example: UseNet * Established in 1980 in the US * Uses UUCP (Unix-to-Unix-Copy) as transport mechanism over Modmes ** UUCP was created in the 1970ies and used to copy files, including Internet Mal * Usenet News format (RFC850) designed very similar to Internet Mail (RFC822) * Hierarchy of News Groups that gets replicated / flooded accross the network * Routing defined in route maps == Curiosity: Floppy Poll/Point * Not everyone had a phone line in the 1990ies ** particularly Eastern Germany had big lack of phone lines * Some people thus exchanged daily floppies in evenlopes and mailed them as postal letters * Messages arrived about one day later, but with 1-2 days latency even inside the dial-up store-and-forward network, it hardly matters image:images/floppy-disk-1219954_640.png[width="30%"] == Internet Early ways to access Internet: * Mail/News via UUCP (as stated earlier) * Dial-Up Modem to a TTY of a Unix machine connected to TCP/IP ** Often workstations at universities. You could then run FTP, IRC, telnet, Gopher on the test console * ftp-mailers ** a FTP client running on a remote machine, whose input/output is used by e-mail ** you send a mail with "ftp ftp.sun.com" and "ls" ** hours or days later you get the list of files ** you respond with cd / get / ... ** hours later you get the file as batch of UUencoded mails == Internet with SLIP * if you had dial-up access to a Unix box * you could run SLIP on both sides, transporting IP over the modem line ** IP. At home. In your apartment !!1! * later superseded by PPP (auto-configuration, authentication, compression, ...) == ISDN * Digital Circuit-Switched Telephony Network ** Transport of Digital Voice (PCM) audio and transparent digital data * Germany ** 1989 put in operation ** Until 1993 German 1TR6 system ** From 1994 European E-DSS1 ** Hugely popularized from 1995 by subsidies == ISDN Terminal Adapter * ISDN is an all-digital network * No modulator / demodulator required * Instead, so-called _terminal adapter_ * Speeds: 64000 (single B-channel) or 128000 (both B-channels) * V.110 as adaptation to do async serial over sync ISDN (1988) image:images/isdn.jpg[width="50%"] == How to get Internet Access? * Hard to access in early/mid 1990ies outside of academia * Almost no commercial ISPs (XLink, EUnet) - and very expensive * Grass-Roots groups of enthusiasts established themselves * Kommunikationsnetz Franken e.V. (KNF, franken.de) one of them ** dial-up UUCP and shortly later IP for personal, non-commercial users ** POPs in Nürnberg, Fürth, Erlangen, Forchheim, Würzburg, Regensburg, ... ** Every user got 6 static IP addresses routed to wherever he dialed in (OSPF!) ** served ~ 800 users / members at peak == Individual Network (IN) e.V. * Umbrella Association established in 1992 ** Goal to help regional member associations with negotiating framework contracts ** Actual technical access via WiN/DFN, XLink, EUnet ** Regional Member Associations include Oche, Augusta, Escape, IN-Berlin, Hanse, INKA, Toppoint, muc.de, IN-Passau, ThurNet, MAUS, CL-Net and many more ** IN members served more than 300,000 users at one point ** Dissolved in 2000, when *** commercial ISPs were widespread, and *** remaining IN member organizations could get decend connectivity with IN e.V. == Internet With packet-switched TCP-IP * you just needed to dial one number * and then access systems world-wide This brought new purpose to leased lines == Analog Leased Lines * Telephone operator permanently interconnects wires at exchange * No signaling (dialtone/ringtone etc) * Requires modems with special capabilities ** ATA without an incoming ring first ** ATD without a dialtone first * In Germany: "Analog G" of Post/Telekom ** I finally could afford one in 1998 ** 900 DM installation cost * 180 DM per month (60 DM per hop) == hub-nbg.franken.de, 1998 image:images/pict3_Lg.jpg[] == ISDN Leased Lines "SPV" * Not really a leased line * Basically only "flat rate calls" to one specific (fixed) destination * Available in national 1TR6 only == Abusing Analog Lines, Part 1 * ICU-T ** inverse of ISDN NTBA ** ISDN BRI (2x64k + 16k) over 12km of telephone line * Special ISDN routers without signaling to use even 16k D-channel for data! Easy upgrade to get performance of a leased ISDN line out of an Analog-G == Leased Lines at KNF, 1997/1998 [graphviz] ---- include::images/knf-leased_lines.dot[] ---- == hub-fue.franken.de, undated image:images/hub-fue-03_Lg.jpg[] == hub-fue.franken.de, undated image:images/hub-fue-04_Lg.jpg[] == Abusing Analog Lines, Part 2 When the first DSL modems became availale in the US * we imported some Ascend DSLpipe * with some fimrwares, they could be used back-to-back (without DSLAM) * suddenly we could get speeds of 2.3 MBps over analog lines ** if they were not too long ** if they didn't have in-line inductors * soon less expensive alternatives came up Pairgain (2000) image:images/ascend.jpg[width="50%"] == From Online Bistro to Internet Cafe * Falken's Maze was an _Online Bistro_ established in the 1990ies ** I became a regular around 1994 * initially had four DOS PCs, each with a Modem, dedicated phone line and a call charge meter ** you could go there, eat + drink and use the PCs to log into BBSs * quickly became preferred meeting point of various nerds, BBS users, SYSOP meetings, etc. * PCs were networked with 10base2 and NetWare (DOOM!) * people started to dial into CompuServe, AOL, etc. * Internet became more popular, Falken's Maze started subsidiary in Nuernberg ** ISDN SPV was used as Internet uplink == Conclusions * The first decade[s] of wide-area electronics communications was powered by a community of enthusiasts * BBS community / culture is a distinct sub-culture. Different norms than HAM radio, Hackers, Free Software, but lots of overlap == Further Reading * http://telnetbbsguide.com/ ** list of active telnet BBSs * http://qodem.sourceforge.net/ ** FOSS multi-platform terminal program * http://artscene.textfiles.com/ansi/ ** Archive of ANSI Artwork * http://www.filegate.net/nodelist/ ** FIDO nodelist of 2017 == EOF End of File