Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!elroy.jpl.nasa.gov!zardoz.cpd.com!neil From: neil@uninet.cpd.com (Neil Gorsuch) Newsgroups: comp.unix.questions Subject: Re: Terminal servers (Was: Looking for a big Unix box) Message-ID: <1990Mar1.012950.14709@zardoz.cpd.com> Date: 1 Mar 90 01:29:50 GMT References: <1990Feb25.075337.22513@zardoz.cpd.com> <24573@princeton.Princeton.EDU> Sender: news@zardoz.cpd.com (usenet news administrator) Reply-To: neil@uninet.UUCP (Neil Gorsuch) Organization: Uninet Peripherals, Santa Ana, CA, USA Lines: 61 In article emv@math.lsa.umich.edu (Edward Vielmetti) writes: >In article <24573@princeton.Princeton.EDU> tr@samadams.princeton.edu (Tom Reingold) writes: > Neil Gorsuch talks about how using an ethernet-based terminal server > can eat up your net bandwidth. My understanding is that the > packets for rlogin and telnet are so few and small that they are > insignificant compared with NFS. Am I wrong? >Neil Gorsuch is selling a product which competes with >ethernet-based terminal servers, and his opinions on >the subject should be considered in that light. I'm Neil Gorsuch 8-). While I love to sell product (entrepreneurial types tend to be that way), I posted the original article to provide a counterpoint to the "you need a big EXPENSIVE computer to handle multiple users" and "you need a big EXPENSIVE workstation to be a server for desktop workstations" attitudes which I find somewhat repugnant. Sometimes, big EXPENSIVE computers are better, sometimes they're not. I would just stress that it is very much worth people's time to investigate and consider non-traditional approaches. Especially considering the wave of under $5000, double digit MIPS workstations just over the horizon. And don't let the people that sell the EXPENSIVE computers be your information source for "small" computer capabilities 8-), or the other way around. If you noticed, the system that I proposed would work equally well whether the terminals were hanging off the ethernet or elsewhere. "Elsewhere" just offers a some technical advantages and some cost savings. My postings are an argument for "smaller is sometimes VERY cost effective", not an argument for "elsewhere". >NFS will eat up your net well before telnet traffic. It depends what you're doing. If you have a bunch of diskless clients hanging off one ethernet, NFS will almost certainly dominate. If, however, you have 1 or 2 large machines with their own disks and a 100 or so users logged in through the ethernet, as was being discussed, there should be almost no NFS traffic, but a lot of character traffic. From what I have been told, with TCP/IP encapsulation, about the best that a single ethernet can do is about 150,000 actual characters a second. If you have 100 people doing editing, with a screen update every 10 seconds, you get 100*24*80/10=19200 characters per second, which is a noticable, but hardly crippling, fraction of the ethernet TCP/IP capability. I know of one case where many, many diskless client workstations are contemplated that will have 32 users each running a single special application system that involves a lot of screen updating. Since they are going to put about 15 diskless clients per server, each server's private ethernet leg will require 15*32*24*80/10=92160 characters per second which would be almost impossible to have co-exist with the NFS read/writes associated with 480 users. Whereas, if you have the character data transfers "elsewhere", it works out very nicely, and enables a BIG cost savings in computer costs. And on that note illustrating an advantage of my particular technology, I will conclude (probably not too many of you have made it to this point 8-) by saying that no one technology is better than others. Particular technologies and strategies will be better and/or save you money in particular cases, and it behooves system designers to be open-minded and consider uncommon configurations. -- Neil Gorsuch INTERNET: neil@uninet.cpd.com UUCP: uunet!zardoz!neil MAIL: 1209 E. Warner, Santa Ana, CA, USA, 92705 PHONE: +1 714 546 1100 Uninet, a division of Custom Product Design, Inc. FAX: +1 714 546 3726 AKA: root, security-request, uuasc-request, postmaster, usenet, news