[email protected] (Barry Merrill) writes: > Did you have the same fun and games I had with Southwestern Bell, > during the 70s-80, as each time I got a faster modem, I was the first > customer with that speed, and their engineers had to come out and > measure which of my 6 lines was sufficiently quiet to be used, > often having to change amplifiers up the line. > I think 1200 was no problem, but I remember very well the 2400, 4800, > 9600, and especially the 19.2 interations that took them several days > to support. > > In 1984 I was using the first Compaq LunchBox ($13000) > with a Barr Systems SDLC card to talk SNA.
re: http://www.garlic.com/~lynn/2013l.html#20 Teletypewriter Model 33 http://www.garlic.com/~lynn/2013l.html#21 Teletypewriter Model 33 http://www.garlic.com/~lynn/2013l.html#22 Teletypewriter Model 33 I was corporate tieline ... so there was some extra care when it was originally setup ... I can only remember once when they had to come out and test various pairs. I had gotten 2400 for 3101 ... but fairly early after getting IBM/PC it was replaced with corporate 2400 "encrypting" modem. there was lots of concern about industrial espionage ... all the internal network links (larger than arpanet/internet from just about the beginning until some late '85 or early '86) required link encryptors. sometime mid-80s, there was claim that half of all link encryptors in the world were on the internal network. in the light of lots of discussion about gov. agencies and encryption ... there were all sorts of problems getting approval for installing link encryptors ... especially when the links crossed national boundaries. in the early 80s, evesdropping on phone line computer traffic ... and especially hotel PBX rooms, was identified as major vulnerability. The corporation did their own 2400 baud encrypting modem that was then mandated for home terminal program and portable "road warrior" PCs. as various previous notes about internal network and dial-up traffic ... none of it was SNA http://www.garlic.com/~lynn/subnetwork.html#internalnet however about the time of NSFNET backbone ... there was lots of mis-information about how SNA/VTAM could be used for the NSFNET backbone ... some old NSFNET related email ... including discussion of the SNA/VTAM misinformation http://www.garlic.com/~lynn/lhwemail.html#nsfnet ... was well as mis-information about why the internal network needed to be converted to SNA/VTAM some of this is also discussed in the referenced cloud computing history threads I had a project I called HSDT http://www.garlic.com/~lynn/subnetwork.html#hsdt and was also working with various of the entities that would participate in NSFNET backbone. I had T1 and faster speed links ... and at the time the SNA/VTAM group even had justification to executive committee why customers didn't need/want links faster than 56kbits. Getting link encryptors for T1 links and faster speed links was really expensive and could be hard to find. This is recent reference in getting involved in building our own link encryptors ... objective was to have it handle at least 20mbits/sec and cost $100 or less. I got into tiff with the corporate encryption group over whether standard DES had been significantly weakened. It took three months to convince them that it was significantly stronger (not weaker) than standard DES ... but as referenced it was hollow victory and I came to realize there were 3kinds of crypto 1) those they don't care about, 2) those you can't do, and 3) those you can only do for them. I was told I could make as many as I wanted ... but couldn't keep/use any of them ... but could sell all of them to a gov. agency. http://www.garlic.com/~lynn/2013k.html#77 -- virtualization experience starting Jan1968, online at home since Mar1970 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
