roger%cfa2@HUCSC.HARVARD.EDU (04/24/87)
In response to Doug Bigelow's query:
We have purchased five Bridge CS/1 terminal servers. Each is configured
to service 64 termiinals using TCP/IP over an ethernet. For VMS hosts we have
one 780 and one microVAX II operating Wollongong, one 780 and about four
microVAX II's with Excelan boards and software. We also have at least two
VAXes running Ultrix, about 20 Sun workstations and a few other
TCP/IP-speaking hosts.
I have been responsible for the installation of the terminal servers and
the TCP/IP on the VMS systems. Our hope was to give service about as
good coming into the VAXes on terminal ports (a mixture of DMA and non-DMA)
and have the flexibility of being able to connect to both VMS and non-VMS
TCP/IP systems.
The results with VMS has been a step backwards in terms of human factors
for the terminal user:
1) X-OFF - X-ON flow control does not work well. When you hit X-OFF (NO
SCROLL) on your terminal, you get lots of characters (hundreds) before
the host stops sending. CTRL-Y, CTRL-C, and CTRL-O have similar problems.
2) Programs which do single-character output to the terminal run *very*
slowly. The worst example we have is the 20/20 spreadsheet program;
another is TeX. It seems that programs written in C often do
their terminal I/O one character at a time.
3) The Excelan Telnet host software does not emulate the VMS read-with-prompt
QIO. The read with prompt allows you to do a write followed by a read
with one I/O call. Excelan implements the write by sending one character
per packet. This is extremely slow, as in topic (2) above. The place
where this is most most frequently agravating is when doing command line
editing; VMS CLI uses a read with prompt when it refreshes the command
line.
All in all, Wollongong seems to behave itself better as a Telnet host than
Excelan.
I don't implicate the Bridge terminal servers in any of this. I have equal
problems when I am using my PC/AT with a 3COM board and ftp Systems telnet
software. The Bridge terminal servers seem to be a well thought-out and
engineered product and I have had pleasing response form both the local and
national technical support people. My principal, but minor, complaint with
the Bridge terminal servers is that they only allow one session per terminal.
I have not tried the TEK TCP as a host yet. I expect to make a temporary
arangement to try it out some time in the next week or two. I'll let you
know how it works.
I welcome response from anyone who has some help with these problems or
who just wants to commiserate.
Roger Hauck
Harvard-Smithsonian
Center for Astrophysics
johnth@batcomputer.tn.cornell.edu (John Thurtell) (04/27/87)
In article <8704252252.AA23325@ucbvax.Berkeley.EDU> roger%cfa2@HUCSC.HARVARD.EDU writes: >In response to Doug Bigelow's query: > > We have purchased five Bridge CS/1 terminal servers. Each is configured > to service 64 termiinals using TCP/IP over an ethernet. For VMS hosts we have > one 780 and one microVAX II operating Wollongong, one 780 and about four > microVAX II's with Excelan boards and software. We also have at least two > VAXes running Ultrix, about 20 Sun workstations and a few other > TCP/IP-speaking hosts. > > 1) X-OFF - X-ON flow control does not work well. When you hit X-OFF (NO > SCROLL) on your terminal, you get lots of characters (hundreds) before > the host stops sending. CTRL-Y, CTRL-C, and CTRL-O have similar problems. I think the problem you are having here is due to where your X-OFF controls are being processed. Many times it will be processed by the distant host (in this case the VAX) and hence the terminal server buffer will need to clear before typing stops. Your terminal server software should let you control this by a) selecting a smaller buffer. b) processing the X-OFF locally. You would probably like to use both of these for your application. You also mention problems with single characters ... I'm not sure what to say about this. I have some experience connecting into the Wollongong software over a TCP/IP network from 5-6 different UNIX systems and 2 CMS systems and I have never had this problem. It sounds like something is not installed correctly. I don't know if it is your Wollongong software or your terminal servers. John Thurtell johnth@batcomputer.uucp thurtell@cheme.tn.cornell.edu p8tj@cornelld.