Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!gatech!bloom-beacon!husc6!mit-eddie!ll-xn!ames!ucbcad!ucbvax!ucdavis!deneb!ccruss From: ccruss@ucdavis.UUCP (Russ Hobby) Newsgroups: comp.protocols.tcp-ip,comp.sys.ibm.pc Subject: Re: PC UNIX wide area networking Message-ID: <626@ucdavis.UUCP> Date: Wed, 15-Jul-87 12:36:01 EDT Article-I.D.: ucdavis.626 Posted: Wed Jul 15 12:36:01 1987 Date-Received: Fri, 17-Jul-87 07:25:18 EDT References: <272@auvax.UUCP> Reply-To: ccruss@ucdavis.edu.UUCP (Russ Hobby) Organization: University of California, Davis Lines: 39 Xref: mnetor comp.protocols.tcp-ip:579 comp.sys.ibm.pc:5721 SLIP connections seem to be a hot topic this summer so I thought I would post a description of a summer project we have at UC Davis. SLIP is a cheap and easy method to get a computer connected to a network and is particularly good for microcomputers since additional hardware is not required. SLIP is lacking in a few areas however. Throughput on slow serial lines (1200/2400 baud) can be quite bad because of the minimum packet size (all those header fields). Also there is no standard method of establishing a SLIP connection for temporary network hookups. Our project addresses the first problem by using an abbreviated IP packet on the SLIP line and have the SLIP gateway build legal packets before sending them onto the network. Likewise, incoming packets will be reduced before sending them down the SLIP line. Many of the fields in the IP packet header are either static or unnecessary, IF you consider the host at the end of the SLIP is a leaf on the network and will not be routing. Static fields are established at login. Our current plans are for four or eight byte headers, depending if the to/from address has changed from the last packet. To solve the second problem, we are creating a standard logon procedure that will make the connection and set the static fields. We plan to support connections via campus serial connection (up to 19.2k) as well as via dialup modems (300/1200/2400 baud, although I can not imagine it working well at 300!). We doing the development with an IBM PC clone on one end and a VAX with 4.3bsd on the other. We have started with some of the MIT PC/IP derivations on the PC side, so that if the project works out, it will usable by others using the same software. If there is interest, I will post information on how well it works. Russell Hobby Data Communications Manager U. C. Davis Computing Services BITNET: RDHOBBY@UCDAVIS Davis Ca 95616 UUCP: ...!ucbvax!ucdavis!rdhobby (916) 752-0236 INTERNET: rdhobby@ucdavis.edu