johnl@ima.UUCP (John R. Levine) (08/18/86)
We have an Ethernet with about 40 IBM PCs and the like on it, along with
a 3Com 3server and a PC AT with a big disk, which act as disk servers. We're
currently running 3Com's EtherShare disk server software, and plan shortly to
switch to 3plus which is based on Microsoft Networks, and is so quite similar
to the software for the IBM token ring.
Some of us need to dial out now and then to various outside machines. At
this point, we have regular modems on four of the machines, but the demand is
increasing and I need to do something about it. An obvious possibility would
be to buy cheapo modems for the machines that need them, but this is a poor
solution since it only forestalls the day when everybody needs a modem, and
is quite expensive not just because of the modems, but because we'd need to
buy several expander boards for our PBX to provide phone lines for the modems.
We can't just share phone lines with people's existing phones because
the phones in the offices are all-digital ROLM phones, and although ROLM
does have an option to put RS-232 plugs on the ROLM phones, it costs a fortune.
I suppose another possibility would be to run RS-232 wire and get a small
data PBX, but that'd be expensive and a lot of work -- pulling wire is a
major pain because our offices have real walls and when we prewired the
offices for Ethernet before the walls went up, we thought we were done.
Besides, we already have every single machine in the office plugged into the
Ethernet. What I'd like to find is a box that plugs into the Ethernet and
has some RS-232 ports on it, and software so that users on the PCs can seize
a port, dial out through terminal emulators, and give the port back when
they're through. It's sort of like a data PBX, but with an Ethernet in the
middle and PCs rather than terminals on the front.
Here are the possibilities that I have found, but I'd like information on
experience that people have had with these or other similar equipment. I
am not afraid of doing a moderate amount of software development if it's
worth the effort.
-- Bridge Communications has a package for their CS/100 box which seems
to do just what we want. Unfortunately, it's overkill -- the Bridge box
has 16 or 32 ports and speaks every protocol known to Western humanity.
Consequently, it's kind of expensive.
-- 3com lets you plug modems into the back of your 3server, but only to
internetwork among 3plus networks, or to dial into the 3server from a remote
PC, at which point the remote PC acts like it's connected to the 3server by
a 1200 baud Ethernet. Useful, but not what I want. Did 3com ever think of
a network based terminal multiplexor? Well yes, actually, they did, and if
I wanted 3270 terminal emulation they'll sell me that, and they even wrote the
PC software for the Bridge system above. So can I dial out through the
3server? Well, no, the way they wrote the 3server software makes it very
hard so don't hold your breath. Feh.
-- DEC has recently announced the terminal servier 200 which, unlike the
100, is reputed to be of use with other than DEC hosts. It's still a
little pricey, but I'd like to hear how it works and how you talk to it.
-- Codex has a new line of Ethernet equipment which includes the 4020
box consisting of 4 RS-232 ports, Ethernet interface, and unspecified
other guts for $1000. Looks promising, but I've had trouble getting any
useful information from Codex. It appears that they want you to buy this
box in a combination with other stuff so you get the effect of an RS-232
data PBX that happens to have an Ethernet in the middle. I don't know if
they document their protocols. I don't even know if they really make it
or whether it's made by some other Motorola subsidiary and relabeled
(like the UDS modems that they also sell.)
Advice and suggestions are appreciated. TIA.
--
John R. Levine, Javelin Software Corp., Cambridge MA +1 617 494 1400
{ ihnp4 | decvax | cbosgd | harvard | yale }!ima!johnl, Levine@YALE.EDU
The opinions expressed herein are solely those of a 12-year-old hacker
who has broken into my account and not those of any person or organization.phil@amdcad.UUCP (08/18/86)
In article <189@ima.UUCP> johnl@ima.UUCP (John R. Levine) writes: >-- DEC has recently announced the terminal servier 200 which, unlike the >100, is reputed to be of use with other than DEC hosts. It's still a >little pricey, but I'd like to hear how it works and how you talk to it. As I understand it, the DEC server 200 speaks only LAT, a proprietary protocol which DEC refuses to release to anybody. I think Henry Spencer has some comments on that attitude. The major "innovation" in the DEC server 200 is that it has reverse LAT, which means you can implement milking machines with it. For example, you could put some modems on a DEC server 200 and connect to them over Ethernet from another DEC server (100 or 200). Or you could probably do a SET/HOST from a VMS machine. But you can't do what you want, which is connect to the modems from a PC on Ethernet. Would you like DEC to support TCP/IP? Call your salesman and let him know. (please!) -- Rain follows the plow. Phil Ngai +1 408 749 5720 UUCP: {ucbvax,decwrl,ihnp4,allegra}!amdcad!phil ARPA: amdcad!phil@decwrl.dec.com
hlh@awsum.UUCP (Henry L. Hall) (08/29/86)
In article <12739@amdcad.UUCP> phil@amdcad.UUCP (Phil Ngai) writes: >The major "innovation" in >the DEC server 200 is that it has reverse LAT, which means you can >implement milking machines with it. For example, you could put some >modems on a DEC server 200 and connect to them over Ethernet from >another DEC server (100 or 200). Or you could probably do a SET/HOST >from a VMS machine. But you can't do what you want, which is connect >to the modems from a PC on Ethernet. > >Would you like DEC to support TCP/IP? Call your salesman and let him >know. (please!) I have heard about a DEC offering called PC/DECNET that I believe does allow some limited DECNET functionality to be accessed by a PC (I don't know what ethernet hardware is supported). There have been enough comments about proprietary format(er)s (RD-53, RX-50), protocols (LAT, MSCP), and bus structures (CI, BI) that I won't add anything more than my 1.5 cents worth (I'm not naming names, after all, just products :-). To DEC's credit, they already sort of support/sell TCP/IP for VMS (via Wollongon) and Ultrix (via native Berkeley code). Of course that's why third party vendors such as my company are around, though; to fill in the gaps in DEC's product line and react quicker to new technology (how long after 256k DRAMS were available did DEC keep selling 16k arrays, and my company's intelligent ethernet cards vs. the DEUNA and even the DELUA). Like I said, that's why third parties are still in business. -- Henry L. Hall +01 (617) 879-0953 Communication Machinery Corp., Eastern Region 945 Concord St. Framingham, MA 01701 {allegra, cbosgd, decvax, gatech, ihnp4, ll-xn, philabs, utzoo} !linus!awsum!hlh