network basics

[Mark Callow]

	Presuming you are using 4.2 networking, what are the best
	options for networking together two Unibus's? Three?
4.2 networking currently supports ethernets and arpanet imp's.
Various people are working on other interfaces such as decnet
and some hardware to talk IBM SNA but I don't have many details.
Ethernet is probably the best bet.

	What are the costs involved, and the risks?
With ethernet, about $1500-$1800 per tap.

	What's supported by 4.2?
Interlan and 3Com controllers are both supported.  You can probably
find a DEUNA (Digital Ethernet-Unibus Adapter) driver from someone.
Read "Hints on Configuring Vax System's for Unix" which came with
your 4.2BSD distribution.  RFM before ASQ.

	If you have a standard driver for any particular
	communications device, can the networking software simply
	use the open/close/read/write interface to communicate over
	that device?
no, No, NO.  The network device drivers are buried in the system.  You
can only get at them through the socket abstraction.  They do not have
entries in /dev.  They are controlled through a bunch of SIOC ioctl's
on sockets most of which are restricted to the superuser.
-- 
>From the TARDIS of Mark Callow
msc at qubix.UUCP,  decwrl!qubix!msc at Berkeley.ARPA
...{decvax,ucbvax,ihnp4}!decwrl!qubix!msc, ...{ittvax,amd70}!qubix!msc

"I'm a citizen of the Universe, and a gentleman to boot!"