[comp.protocols.tcp-ip] PSN Physical connections.

BILLW@MATHOM.CISCO.COM (William Westfield) (02/24/88)

Is there an RFC or other document someplace that describes the
physical connection between a host and a PSN?  This was a lot easier
in the 1822 days, but now there is rs232, rs449, v.35, dce, dte,
internal clocking, external clocking, providing an external clock, and
all sorts of other things that are necessary to get X.25 working
properly...  There are apparently several varieties of interface
available on the PSN, not to mention several types of PSNs.  Id like
to know ALL the available configurations, so that I can tell people
"yes, to connect a cisco Gateway to your PSN, you will also need and
X, a Y, and a Z, or you can get the PSN reconfigured to be FOO, in
which case you won't need the Z any more".

Thankyou
Bill Westfield
cisco Systems.
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gaw@columbia-pdn (Glen A. Warholic) (02/24/88)

If such a document existed it would be worth a fortune and I doubt if
asking for it would get you it.

Seriously I have never seen one and as you stated during the
days of 1822 you could pull out good old report 1822 and be ready
to go.  But now with V.35 on an RS-449 connector and the new move to
put a clock generator in the PSN(DTE) so that it can connect to
another DTE(host/gateway) without the use of a modem eliminator,
the number of possibilities of the ways to connect to a PSN
can be mind boggling.

turkewit@CCV.BBN.COM ("Kenneth A. Turkewitz") (02/24/88)

Bill,
	There is such a document that was written by BBN Communications
for DCA last year.  It is called "C/30E Physical Layer Interface Guide."
I believe that DCA was going to add a few things and publish this in
some easily obtainable mode.  (The cover of the document includes,
"DCAI No: DCAI-350-180-()."  I'm not sure whether or not this will help
uniquely identify the document to DCA.)
	I would check with DCEC (start with Charlie Morgan,
"CEMorgan@DDN1.arpa") to find out the status of this document.  He
might also know how to obtain a copy of it.
		--Ken Turkewitz

cpw%sneezy@LANL.GOV (C. Philip Wood) (02/25/88)

This reminds me of the time, about 2 months ago, when we attemted to use
Sun Microsystems, Inc. MCP board, their SUNLINK X.25 software, and a
PDN to see what kind of connectivity we could get.  Like communicating
with other nodes off the PDN.  We had a serial line junky in here, with
mucho patents to his name, a million dollor serial line analyzer with
lots of beautiful color monitor displays, and various loopback plugs.
It took a couple of days, and visits from various Mountain Bell types
before we could "pad" on over to a Microvax, via Phoenix at 56 Kbits.
We never did get the Internet Router to work, but thats another story
which is "fixed in 4.0"

Phil Wood   cpw@lanl.gov