ldr@hou2b.UUCP (L.RUBIN) (11/19/85)
We are looking into buying an ethernet with TCIP to run from our VAX785 running division 452 unix V.2 that we will hook our apollos and our sun workstations onto. I spoke to EXCELAN who told me that they will give us binaries for TCPIP and source for application software (eg file transfers, remote logins) that is appropriate for V.2 that ATT sells externally. Does anyone know if I will have a problem if I buy their stuff. The 452 hotline people say I should only need to recompile the source... Is this true, we cant afford to spend lots of time getting our ethernet working???
medin@lll-crg.ARpA (Milo Medin) (11/25/85)
Well, the excelan product may be ok for your particular set-up, but its given us here a real haedache. The problem is, (at least with our version of the software) that the Excelan IP doesn't know about internet routing! Now, if you have everything hooked on a single cable, this won't bother you, but if you'd like to use a gateway to talk to something like the MILNET, you lose big. At least the present version of software doesn't crash the machine when it got something from an address it didn't know about like older versions did (specifically for the IRIS workstation). It prints a message on the console saying that it doesnt know who the other guy is and ignores the packet. This is true for intel boards on 310 systems and hypercubes, SGI IRIS workstations, and IBM PC's. I don't know about VMS but I'd suspect its the same way there. Also, some other folks here at Ames used the boards over a sky link between 2 vitalink boxes and discovered that the TCP on the board only lets one packet or so be outstanding without an ack, now this isn't too bad on direct ether links, but over satellite links you get massacred by the long transit time. You'd probably notice this too on the MILNET, but since you can't use gateways anyway, it probably doesn't matter. I know CMC makes these type of boards too, but I'm not sure that they do routing either. If you folks who build these things are out there, PLEASE FIX THIS PROBLEM! Even the ability to use a default route and do the rest with ICMP redirects would be decent. Its really not that hard to do. $Flame on$ I really get tired of people making silly mistakes like this when there are so many examples of how to do it right around. Many people just don't want to learn from the experiences of the arpanet people. I had some folks over from Intel awhile ago peddling their ISO wares, and I asked them, "Do you handle internet routing?" They didn't know what I was talking about. I had to explain to them what a gateway was and what it did, and the reason why you need gateways in the first place. I am very pessimistic about how interoperable these ISO products are going to be when you have a bunch of amateurs building all this stuff. Oh well, at least we have something that works. $Flame off$ Milo Medin NASA Ames Research Center
tcs@usna.UUCP (Terry Slattery <tcs@usna>) (11/25/85)
> Well, the excelan product may be ok for your particular set-up, but > its given us here a real haedache. The problem is, (at least with our > version of the software) that the Excelan IP doesn't know about > internet routing! > > Also, some other folks here at Ames used the boards over a sky link > between 2 vitalink boxes and discovered that the TCP on the board > only lets one packet or so be outstanding without an ack, now > this isn't too bad on direct ether links, but over satellite > links you get massacred by the long transit time. You'd probably > notice this too on the MILNET, but since you can't use gateways > anyway, it probably doesn't matter. The current product that Excelan is marketing PROPERLY HANDLES GATEWAY ROUTING! You want version 3.2 of their software. I have a 2.9BSD PDP11 here running V3.2 (I was a beta test site) and can talk on the internet (MILNET) with it. As far as I know, the SGI workstations are still using 3.1a. Pound on SGI to get the latest release out. I've had 3.2 since August. We have an SGI also and it still doesn't know about routing but I intend to ask about it at the Defense Computer Graphics Conference in Washington, D.C. next week. It's about time they got it distriubted. I can't comment on the single outstanding packet problem since I havn't done extensive internet testing. I'm quite pleased with Excelan's 3.2 version of their TCP/IP software. It's been cleaned up quite a bit and the glaring problems you mentioned have been fixed. One aggrivating thing though; rlogind & telnetd run in the card and the interface into the kernel is via a serial multiplexor type driver. So you wind up with getty running on all the ptty lines (no auto-authentication for rlogin). It uses the 4.1a network semantics, so work is needed to port 4.2/3 programs. I also have implemented BRL's MDQS spooling system and it worked first time! Really slick! -tcs Terry Slattery U.S. Naval Academy 301-267-4413 ARPA: tcs@usna.arpa UUCP: decvax!brl-bmd!usna!tcs