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From: cwd@cuae2.UUCP (Chris Donahue)
Newsgroups: net.micro.att
Subject: Re: 3bnet
Message-ID: <283@cuae2.UUCP>
Date: Wed, 29-May-85 09:02:31 EDT
Article-I.D.: cuae2.283
Posted: Wed May 29 09:02:31 1985
Date-Received: Thu, 30-May-85 20:17:54 EDT
References: <1800@ukma.UUCP> <202@uwvax.UUCP>
Organization: AT&T-IS, /app/eng, Lisle, IL
Lines: 39

> can you, or anyone else, tell me about 3bnet?
> david parter
> UWisc Systems Lab
> 

3BNET is an Ethernet compatible local area network for the AT&T 3B Computer
Family. 3BNET is supported on the 3B20S, 3B20A, 3B5 family, and 3B2/300
computers. The transmission rate is 10Mbps over a baseband coax cable media
using CSMA/CD as the transmission algorithm. The network can be 500 meters
end-to-end if thick Ethernet cable is used (in multiples of 2.5 meters
between transceivers) or 400 meters end-to-end if thin Ethernet cable is used
(in multiples of 1 meter between transceivers). Up to 100 computers can
be connected to the network. 3BNET provides bulk file
transfer, remote command execution, electronic mail, and an Application
Programming Interface to allow users to develop custom network software.

The 3BNET Network Interface for the AT&T 3B2/300 Computer is based in
the Intel 82586 Ethernet chip set with the Intel 80186 providing bus
handshake control. The card does all of the level 2 protocol processing
and allows 3BNET to be a low host overhead communications feature.
3BNET itself is AT&T's high level protocol above the Ethernet Data Link Layer.

The Application Programming Interface allows programmers to directly access
network services at the Ethernet Data Link Layer through the use of standard
UNIX System calls: read, write, open, close, ioctl. The programmer can
construct programs that communicate with each other by sending Ethernet
packets that they construct. The user opens an Application Port for reading
from the network or writing to the network or both, sets
several parameters (such as his symbolic address for receiving packets,
protocol type, etc.), and is then ready to send/receive packets.
I have written file servers, print servers, etc. to be used at COMDEX
shows to demonstrate the Application Programming Interface.

Got the idea? Or should I stay on my soap box a while longer?

                                           Chris Donahue
                                           AT&T Info. Sys.
                                           Application Engineering
                                           Lisle, IL