[comp.unix.aux] tcp-ip terminal servers

jle@ece-csc.UUCP (Jamie Evans) (10/12/88)

I am currently interested in purchasing a tcp/ip terminal server for 
the department here at Virginia Tech. We currently have a network
consisting of a DEC 3500 and 2000 running Ultrix, 30 Macintosh A/UX 
systems, a Sun and numerous AT&T pcs. We would like to have a tcp/ip
terminal server for our terminal room and to allow faculty to call
in from home. I am interested in any vendor information/prices/contacts
that anyone could offer. I am currently accessing USENET from NC State
so if you have any suggestions of what servers are better than others, 
suggestions, etc. please let me know. 

I can be reached via e-mail at jle@vtopus.cs.vt.edu, through Applelink
via U60 or by phone at 703-961-6931.

Thanks in advance....


	-Jamie Evans-
	Director of Computing
	CS Department
	Virginia Tech

ron@ron.rutgers.edu (Ron Natalie) (10/13/88)

The two leaders, in my opinion, are ENCORE and CISCO.  They seem to trade
back and forth as to functionality.  The ENCORE probably provides more
user facilities (like the ability to get parts of EMACS in the terminal
servers).  CISCO wins out on the fact that you can put 96 lines in a
single box.  This is handy for large scale central modem banks or bign
terminal rooms (the big box turns out to be much cheaper than several of
the smaller ones).

There are other units available from Bridge, UB, Micom, Xyplex, and Develcon.
These are probably lagging slightly behind the leaders in general niceness
and bang for the buck.

-Ron

haas@wasatch.UUCP (Walt Haas) (10/18/88)

I've been evaluating terminal servers and am not too pleased with the results
so far.  The application I have in mind is a little different from the usual-
I want to put a TCP/IP/Ethernet server back-to-back with a Zenith Z-LAN NCU
so that users of the Z-LAN network can access Ethernet machines and
vice versa.  Therefore the TCP/IP server must simultaneously provide both
modem control and hardware flow control in both directions.  This rules out
use of the cisco ASM and the Encore Annex, sigh, both of which look like
good boxes in most other respects.

3com/Bridge loaned me a CS/1 for evaluation and it does the modem and flow
control fine.  Unfortunately it doesn't support rlogin and refuses to ping
a multihomed host (like, for example, cs.utah.edu).  I talked to the
software support guy at 3com/Bridge about this and his reply was that they
had no plans to support rlogin, and you shouldn't give two IP addresses
to the same host (!).  So from that I think we can safely say that they
can't support their software.

Incidentally I wrote their President a letter asking him to please get
onto the Internet so I wouldn't have to play telephone tag for a week
at a time to talk to his guys.  He never replied to the letter.

Right now I have a Micom/Interlan NTS-100 downstairs to evaluate.  Their
literature says it supports rlogin but I can't fin any sign of rlogin
in the actual firmware - plus there are a slew of obvious bugs.  Probably
I just got an old copy of the firmware but their tech support guys aren't
returning phone calls - at least not with any degree of rapidity.  I know
somebody on the net posts from Interlan - it seems, however, that this is
not known to their management, or at least is not thought of as a way
to support customers, because the local rep has been beating on them to
improve the accessibility of their support and he reports that Micom/
Interlan management isn't even aware that this channel exists.

So would all you folks with brilliant ideas about how to solve this
problem mind coming out of the woodwork with your bright ideas?

Thanks in advance  -- Walt Haas   haas@cs.utah.edu   utah-cs!haas

kwe@bu-cs.BU.EDU (kwe@bu-it.bu.edu (Kent W. England)) (10/19/88)

In article <417@wasatch.UUCP> haas@wasatch.UUCP (Walt Haas) writes:
>I've been evaluating terminal servers and am not too pleased with the results
>so far.  The application I have in mind is a little different from the usual-
>I want to put a TCP/IP/Ethernet server back-to-back with a Zenith Z-LAN NCU
>so that users of the Z-LAN network can access Ethernet machines and
>vice versa.  Therefore the TCP/IP server must simultaneously provide both
>modem control and hardware flow control in both directions.  This rules out
>use of the cisco ASM and the Encore Annex, sigh, both of which look like
>good boxes in most other respects.
>
>So would all you folks with brilliant ideas about how to solve this
>problem mind coming out of the woodwork with your bright ideas?
>
	You are right about the products:  those that do good telnet
and rlogin don't understand serial lines and those that understand
serial lines (like U-B, Sytek, ...) don't do rlogin, domain name, etc
very well.

	I think part of the problem is trying to minimize the number
of pins supported.  The vendors want to use just four or five signals
when we need eight (but not always all at the same time).  Using eight
signals only allows six circuits on a 50 pin telco connector.  Using
six or fewer signals lets you put eight circuits on a 50 pin telco.  I
don't think a lot of the hardware design goes much beyond those decisions.

	It's my opinion that, at a minimum, your serial interface
needs to support a connect/disconnect hardware handshake and a
ready/clear flow control handshake.  connect/disconnect is usually
dtr/dsr or dtr/cd.  Hardware flow control is usually rts/cts.  But no
matter; you can always remap the flow control or conn/disconn signals
to other pins on your punchdown or in your RJ/DB adaptor.  The point
is that you need the functionality of handshaking upon connect and
disconnect (how many of you have systems that don't close sessions
when the modem line is dropped?) and you need hardware flow control
sometimes (you always need flow control, either soft or hard).  Of
course, you need three data signals.  That's seven or eight signals
depending on whether dsr and cd have different characteristics.

	I can get along without ring indicator, speed, and busy out,
but there are those who will have difficulty without those signals.
Could we at least agree on the need for connect/disconnect and
hardware flow control handshaking?  If they could give us that much we
could build most of our terminal clusters and modem pools and host
front ends.

	Of course, there will be problems with "normally on" versus
"normally off" and toggle times (oops, the vax missed the toggle,
sorry your session is still open), but that's why we have to get away
from RS232 eventually.

	Kent England, Boston University

sean@cadre.dsl.PITTSBURGH.EDU (Sean McLinden) (10/19/88)

In article <417@wasatch.UUCP> haas@wasatch.UUCP (Walt Haas) writes:
>Right now I have a Micom/Interlan NTS-100 downstairs to evaluate.

Forget it! We have one of these (obtained from Black Box) and
the software is ancient. Their implementation of telnet is poor
and they don't support two way ports (which would allow you
to dial in or out). You have to disable the modem talk modes
because they interfere with the telnet protocol (when will
somebody fix this). Most of all, the support (which used to
be quite good with this company), really stinks.

What would be ideal is a server which had downloadable software
and a standard cpu (like a 68000), which would allow you to
write your own code and load it. That way you could support
SUPDUP, telnet, ROSE, or any old protocol that you like. In
the meantime, get LSI-11s and do it yourself.

Sean McLinden
Decision Systems Laboratory

haas@wasatch.UUCP (Walt Haas) (10/22/88)

In article <417@wasatch.UUCP>, I wrote:
> 3com/Bridge loaned me a CS/1 for evaluation and it does the modem and flow
> control fine.  Unfortunately it doesn't support rlogin and refuses to ping
> a multihomed host (like, for example, cs.utah.edu).  I talked to the
> software support guy at 3com/Bridge about this and his reply was that they
> had no plans to support rlogin, and you shouldn't give two IP addresses
> to the same host (!).  So from that I think we can safely say that they
> can't support their software.

The reaction to this posting was quite interesting!  Firstly I received a
number of messages from 3com/Bridge people expressing concern that I did
not feel I was getting the quality of support that they tried to provide.
Clearly they are working hard to provide good support.  However many people
who responded did not understand what I expected rlogin to do, so let me
clarify what it does in the cisco and Encore products.  The user does
*not* log in to the terminal server, the user merely specifes use of the
rlogin protocol instead of the TELNET protocol.  Rlogin has the advantage
of making the terminal server much more transparent than a server running
TELNET.  Rlogin is the protocol of choice for users who have a choice.

> Incidentally I wrote their President a letter asking him to please get
> onto the Internet so I wouldn't have to play telephone tag for a week
> at a time to talk to his guys.  He never replied to the letter.

Several people provided uucp paths to Bridge and/or 3com, but none knew
of a username or alias set up to receive requests for service.  One
respondent said that their request to get connected to the Internet was being
held in some sort of queue, but they expected to be connected soon.

> Right now I have a Micom/Interlan NTS-100 downstairs to evaluate.  Their
> literature says it supports rlogin but I can't fine any sign of rlogin
> in the actual firmware - plus there are a slew of obvious bugs.  Probably
> I just got an old copy of the firmware but their tech support guys aren't
> returning phone calls - at least not with any degree of rapidity.

The local rep finally got the current firmware out of them after two tries.
I have it downstairs now and it does have some rlogin support, but there
still seem to be a few problems.  Perhaps I just haven't learned to configure
it correctly yet.  

> I know somebody on the net posts from Interlan ...

It was interesting to note that there was no response from Micom/Interlan
protesting that they try hard to give good service.  This is consistent
with the way they don't answer phone calls.

Be happy, don't worry  -- Walt Haas   haas@cs.utah.edu   utah-cs!haas

backman@interlan.UUCP (Larry Backman) (10/27/88)

In article <426@wasatch.UUCP> haas@wasatch.UUCP (Walt Haas) writes:
>
>> I know somebody on the net posts from Interlan ...
>
>It was interesting to note that there was no response from Micom/Interlan
>protesting that they try hard to give good service.  This is consistent
>with the way they don't answer phone calls.
>

	[]

	Keep those letters coming folks... We are now InterLAN, Inc;
	I have been feeding this sequence of postings to the new person
	in charge of support.  His name is Steve Young, I thhink you can
	reach him at this machine (young@interlan)

					Larry Backman

efb@suned1.UUCP (Everett F. Batey II) (10/27/88)

Couldn't let be mention of the NTS100 TELNET / rlogin SERVERS.  They do when
the rep finally gets you the current ROM pack.  Then the puke from the factory 
says you have to return it or pay for it again .. sure come see me .. and the 
company attorney .. It works for me with modem inbound .. not so well but use-
able for outbound .. not UUCP.  We have been pretty stable for nearly a year.

For outbound services you want only one service class per server as best I can 
tell.  They take some getting used to.  Think I would prefer to LAT from a 
DEC Server to a telnet capable VAX if dollars weren't binding condition.

MY QUESTION.  We are on a site with a 192... address assigned.  That is across
a MILnet gateway.  To use my telnet / rlogin servers, must I consume some of
those 254 addresses?  Is there a network legal way to be on another net number
in the 255.255.255. upper 24 bits?  Which my local hosts can see and still
get helped NS from my local domain internal name server?

WHAT does every one else with multiple hosts and servers on a local ethernet
gatewayed to ARPA / Internet do to preserve host addresses with servers?  Do
your servers telnet to folks across the gateway?  We are still a way from
connected and I would appreciate some planning help .. thanks /Ev/
-- 
           The_Main_User (So Calif SunLUG | Vta-SB-SLO-DECUS)
    efb@elroy.JPL.Nasa.Gov sun!tsunami!suned1!efb efbatey@nswses.arpa
      Statements, Opinions ... MINE ... NOT those of my US Employer