Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site ucbvax.BERKELEY.EDU Path: utzoo!decvax!ucbvax!andrew.cmu.edu!leong From: leong@andrew.cmu.edu (John Leong) Newsgroups: mod.protocols.tcp-ip Subject: Re: Ethernet carrier sense during transmit Message-ID: Date: Thu, 2-Oct-86 18:30:49 EDT Article-I.D.: andrew.MS.V3.10.leong.0.leong.168.0 Posted: Thu Oct 2 18:30:49 1986 Date-Received: Wed, 8-Oct-86 03:42:03 EDT Sender: daemon@ucbvax.BERKELEY.EDU Organization: The ARPA Internet Lines: 22 Approved: tcp-ip@sri-nic.arpa Re : "..... Ethernet assumes a certain maximum transceiver cable length and a certain minimum signal propagation velocity .... The Codenoll system alters the parameters which permit the monitoring of carrier. As such, calling it "Ethernet" or "Ethernet compatible" could be misleading and could cause network failures which are hard to diagnose such as your case. ...... " I am curious as to how the Remote LANBridge function in conjunction with the DEC remote repeater. Does the AMD chip inside the LANbridge, pointing to the direction of the long fibre link, programmed to carry out the CarrierSenseTest ? Furthermore, it is my contention that doing a CarrierSenseTest is probably a good thing but the timing is questionable bearing in mind that the 50 meter transciever cable distance is really a function of DC power attenuation between the controller an the transceiver. If the tranceiver is locally powered, that distance limitation would not have applied. The only relevant number will then be the 51.2 microseconds (512 bits) slot time.