From: utzoo!decvax!cca!obrien@RAND-UNIX@sri-unix Newsgroups: net.unix-wizards Title: Re: Very Distant Host support under 4.1bsd Unix. Article-I.D.: sri-unix.3200 Posted: Fri Sep 10 01:34:02 1982 Received: Fri Sep 10 06:56:04 1982 Date: Wednesday, 8 Sep 1982 10:29-PDT I have never actually attempted to run VDH, but everyone I've ever talked to has been very negative about the experience. It is apparently extremely difficult to get the software exactly right for checksumming, etc. the packets from the IMP, and the link is very, very slow. If your phone Co. is good you might try running a local host interface using ACC ECU boxes, which shove 1822 over a phone line using SDLC. These let you run a local/distant host interface over miles and miles of phone line, if your IMP actually has room in it for a local/distant interface. Our own experience in this department has not been sterling, because we have General Telephone here. The link to Rand-Relay is an ECU link over a leased line to an IMP four or five miles away. This link worked just fine until the Rixon-Sangamo T209 modem on the other end blew up, and it hasn't been right since. Our new C-30 eliminates our need for this link. It seems to be a little-known fact that on a Honeywell TIP, the TIP hardware takes up so much rack space that the fourth hookup to the IMP MUST be a VDH. On C-30's this restriction has been removed. That was our situation and is the reason we chose to run with ECU's to an IMP miles away, rather than attempting to run VDH for 50 feet. After Gen. Tel. I'm not sure which alternative was worse.