Path: utzoo!utgpu!attcan!uunet!husc6!mailrus!uwmcsd1!ig!agate!ucbvax!WARBUCKS.AI.SRI.COM!adelman
From: adelman@WARBUCKS.AI.SRI.COM (Kenneth Adelman)
Newsgroups: comp.os.vms
Subject: Re: DECNET over Telnet
Message-ID: <880721104919.bc@Warbucks.AI.SRI.COM>
Date: 21 Jul 88 18:02:31 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: Adelman@Warbucks.AI.SRI.COM (Kenneth Adelman)
Organization: The Internet
Lines: 42

> Does anyone know if you can run asynchronous DECnet over a telnet connection?

    I don't know of anyone who has done this, but is in theory
possible.  You would need to have a VMS terminal driver on both sides
of the telnet connection. In other words, use a psuedo-terminal for
the telnet outbound as well as the telnet inbound and use SET HOST/DTE
instead of a program like TELNET which talks to the network directly.
Then you could SET TERM/SWITCH=DECNET/PROTOCOL=DDCMP and cross your
fingers.  Sounds tricky, and a kludge at best.

> Any other way to run Decnet over a non-proprietary
> link (like using an IP router to route DECNET 8-) ) would be appreciated.

    Many people have implemented DECnet over a 'non-DIGITAL' link.  I
believe Simpact runs DECnet over one of their own devices using a
special driver.  We run DECnet over IP using SRI International's
MultiNet TCP/IP.

> Obviously this is not a high performance configuration.

    I don't claim to be unbaised here because I wrote the code for
MultiNet to do this. The only performance testing I did was running
DECnet over IP between an 11/730 (yech) and an 8600 both with DEUNAs.
I tested throughput using DTSEND/DTRECV and COPY running DECnet over
the DEUNAs and then comparing it to DECnet over IP over the DEUNAs
(using the DEUNAs in a mode where they could be shared with DECnet!).
I found I was able to obtain 3/8ths the throughput with DECnet over
IP as I was with straight DECnet. I kernel profiler showed the reason
for this was that the 11/730 was spending almost 100% of the time on
the interupt stack in the Berkeley TCP code. I suspect with faster
machines or slower links the throughput would approach 100%.

    We don't have any DEC ethernet cards in our lab. We run DECnet
between our two of our VAXen using DECnet over IP via an Interlan
ethernet card.

    Of course when I go home connect by VS-2000 using Async DECnet
and run IP over DECnet to get back to SRI [which we implement in the
kernel]!

					    Kenneth Adelman
					    MultiNet project