raisch@convex.msu.edu (R. Raisch) (06/15/90)
I have a scenerio here that I would like to run past you all.
I have a customer who would like to add networking capabilities to his
line of industrial controllers. He runs on his own buss and thus he will
be building his own Ether card, which will include an 80186 and any ram/rom
needed. He would like to support, in the first cut, TCP-IP and possibly DECNET.
Questions:
1. The only chip set that I have any info on is the Intel network
set. Any comments, recommendations or condemnations?
2. As I understand it, if the chips are NOT running in promiscuious
mode, all I would get to see, (as the network protocol stack), woud be
packets that were addressed to me, as well as any broadcast packets.
Is this correct?
3. The functionality that the controller needs to support is a simple
ability of receiving data from a packet and sending data out. It is
my intention not to write the whole TCP/IP stack on the controller
card, but to interpret the packet "on the fly" and only act on those
packets that were specifically required. (Ie. If I am going to
be supporting a TCP layer connection, look at the packet and discard
any that were not TCP packets.) This raises a few questions:
a. What are the merits of IP over UDP over TCP, as far as
ease of interpretation?
b. What MUST I support in terms of extra protocols? I will
support ICMP-ECHO but beyond that I am hazy. What about
ARPs?
c. In the BEST OF ALL POSSIBLE WORLDS, we need to be able to
handle 8k octets of data every millisecond. I realize that
this is WAY overboard in terms of bandwidth. So, what kind
of response CAN I expect, assuming one host, one controller
on the same net?
I am interested in anyone's impressions of my approach, and any opinions that
you might be able to offer. Thanks, rr
--
Robert Raisch - TechnoJunkie & UnixNut| UseNet: {uunet,mailrus}!frith!raisch
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