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 Network Software Group-301 Comp.Center| InterNet: raisch@frith.egr.msu.edu Michigan State University, E. Lansing | ICBMNet: 084 28 50 W / 42 43 29 N