Path: utzoo!attcan!uunet!wuarchive!emory!sol.ctr.columbia.edu!cica!tut.cis.ohio-state.edu!pacific.mps.ohio-state.edu!zaphod.mps.ohio-state.edu!mips!twg.com!david From: david@twg.com (David S. Herron) Newsgroups: comp.sys.att Subject: Re: IP over starlan? Message-ID: <7620@gollum.twg.com> Date: 17 Jul 90 23:17:18 GMT References: <1042@rossignol.Princeton.EDU> Reply-To: david@twg.com (David S. Herron) Distribution: na Organization: The Wollongong Group, Palo Alto, CA Lines: 30 In article <1042@rossignol.Princeton.EDU> tr@samadams.princeton.edu (Tom Reingold) writes: >Not familiar with Starlan. Want to know if you can talk IP (as in >TCP/IP) over it while regular Starlan messages are going over it. Will >this interfere or what? My question is based on the fact that you can >run IP, Decnet, and Chaosnet over ethernet hardware. Starlan-the-physical-medium is simply a version of ethernet. The 1-mbit-per-second version is simply ethernet-running-at-1-mbit. The 10-mbit version is `regular' ethernet. These are over something which is basically (or really is) twisted pair. Starlan-the-networking-protocol-suite is simply one of the many protocols which can run over ethernet. Ethernet's frames (packets) contain as one of the header fields a protocol field. Protocol numbers have been assigned to all the protocols you mention above, as well as others. Assumably inside the OS between the device driver and the protocol level is a switch routine which takes that protocol number and hands it off to the bottom of the right protocol stack. Note that the ability to run both inside one SysV machine is a moderately recent innovation. Under some previous version of SysV this was not possible .. I just don't remember how far back in the mists of time that is. -- <- David Herron, an MMDF weenie, <- Formerly: David Herron -- NonResident E-Mail Hack <- <- Sign me up for one "I survived Jaka's Story" T-shirt!