lane@SUMEX-AIM.STANFORD.EDU (Christopher Lane) (10/15/90)
In <1990Oct14.063939.13655@midway.uchicago.edu>, paul@zaphod.uchicago.edu writes: >In article <9037@helios.TAMU.EDU> cnh5730@calvin.tamu.edu (Chuck Herrick) writes: >>In article <MailManager.655745779.1575.lane@ssrg-next-1.stanford.edu) lane@SUMEX-AIM.STANFORD.EDU (Christopher Lane) writes: >>>Now that NeXT has 15,000 new orders, does that mean we're going to see twice >>>the number of 'how do I put my ThinNet NeXT on our ThickNet cable' questions >>>than have been already been posted? Just something to look forward to. >>> >>I find it encouraging that people who may not be ethernet gurus >>are buying NeXTs and putting their machines on the net. They're as >>welcome as anyone else, and the net is better for them. >> >OK, I'll bite...how DO you connect your NeXT to thick ethernet? Without >spending $1000 or more, that is? What's the best deal in town? The >inquiring thousands want to know :-} First of all, I'm glad that new users have Chuck to welcome them to the net though my comment was not meant to discourage them but rather to encourage those considering putting together a 'FAQ' posting for comp.sys.next to do so before we come full cycle. Secondly, there are several possible ways to connecting a NeXT to thick ethernet. If you have a large network, then you will probably have to spend the money for a proper repeater. We originally used an old Xerox single port repeater (originally intended for combining thick net branches) and a thin net transceiver. We then daisy-chained the NeXTs together with thin net. The local network police caught up with us and substituted a multi-port repeater and now were running separate thin net segments to each host or cluster. This is the $1000 or more solution you mentioned. We still use the old Xerox single port repeaters (nobody else wants them ;-) when connecting a single thin net host to a thick net segment (as a sort of super transceiver). If you have a tiny network, you can do the above as well or some other things that are easier, cheaper and/or more questionable. One approach is 'direct connect' which I'll use to put a NeXT on my existing thick net at home (doesn't everybody?) which can be done a couple of ways. One approach is to get a thick to thin connector/convertor and put it on the end of the thick net and then start adding thin ethernet cable (putting the terminator on the end of the thin net using another cable convertor or a real thin ethernet terminator). This shortens how physically long you can make your network (by a function of the relative amounts of each type of cable). Another, trickier, 'direct connect' approach is to skip the thin net cable altogether and bring the thick net right up to the back of the NeXT and use a thick net 'T' connector and then use a convertor/connector to get from the 'T' to BNC. I've not tried this myself yet but it is how large portions of our original thick 3MB experimental Ethernet were put together. (The stinger connections on the transcievers were always suspect so our hardware guru converted them to BNC.) I don't know how this effects the physical length of the net but my guess is it's not significant. Unfortunately, thick cable is physically harder to run from host to host. Another 'tiny' network solution is to replace the thick net cable completely with thin net as thick net (i.e. drop cable) hosts can be put onto thin net using an appropriate transceiver. Most newer transceivers have interchangeable connectors for either thick or thin net cable so you know the electronics are the same. We've a couple of Suns and other thick net hosts connected to one of our thin ethernet segments in this fashion. This is only cost effective if the cost of the transceivers you need is less than the repeater. In general, I've found that the typical Ethernet is more flexible with respect to what you can get away with than the typical network administrator. - Christopher -------