From:	MERC::"uunet!CRVAX.SRI.COM!RELAY-INFO-VAX" 19-OCT-1992 04:19:33.16
To:	info-vax@kl.sri.com
CC:	
Subj:	I'M BACK:  TCP/IP over Dialup DECServers


	Hello again,

	Not content with the current swarm of hornets I got buzzing about,
I thought I'd try to "bust the bank" with another topic, and we'll see if
we hit any ol' sore points on this guy!

	Have you ever noticed that DECnet and TCP/IP don't seem to run
very well over LAT-based DECServers?  So did I.  Well, it occured to me
that a suitably-written set of device drivers could probably be used to
take over a LAT port away from the Class Driver, and then utilize a
a data-link layer protocol that escapes out all of the usual Hayes "AT"
codes, as well as insures that the entire packet got transmitted, even
through the busiest networks and bridges.

	Functionally, it would take on the appearance of doing a
"$ SET HOST/DTE nnn", where you then dial out to the remote site, connect
to the terminal server there, establish a connection and log into the
remote computer.  Once logged in, you then would do something that is
the generic equivalent of "$ SET TERM/PROTOCOL=DDCMP/SWI=DECNET" at which
point the custom driver takes over and you have a serial communication
device that will allow you to run DECnet and/or TCP/IP over it.

	In the case of TCP/IP, perhaps the driver would manifest itself as
a pseudo-Ethernet device, so that you could simply configure a second
Network Interface abstraction to it, and then let ARP do its job of figuring
out who's on the other end (instead of implementing a PPP).

	In other words, the startup logic fragment might have:

		$ MC SYSGEN CONNECT XQB0/NOADAPT/DRIVER=MYDRIVER

	then you point your network interfaces as such:

		EP0 -> XQA0		(physical Ethernet)
		EP1 -> XQB0		(fake Ethernet)

	And then do your usual IFCONFIGs to set everything up.

		$ IfConfig EP0  aa.bb.cc.dd  netmask ......
		$ IfConfig EP1  ww.xx.yy.zz  netmask ......

	Mind you, this does you no good for DECnet, because if you have an
end-node license, then you have to choose one Ethernet or the other.

	Anyway, those are my ramblings for tonight.  I'm currently
working on such a beastie, and should have a beta version ready before
tooo long for testing, if anyone is interested.  Please comment or "Plug
Away" with your ideas.  Thanks!


-- 
Bill Laut			Internet:  laut@alien.gici.com
Gull Island Consultants, Inc.	Phone:     (616) 780-3321
Muskegon, MI  49440		>> "Usual disclaimers, apply within" <<

"Praise the Lord from the earth, ye dragons and all deeps."   Psalm 148:7