Xref: utzoo comp.sys.mac:32077 comp.protocols.appletalk:1973 Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!ames!coherent!dplatt From: dplatt@coherent.com (Dave Platt) Newsgroups: comp.sys.mac,comp.protocols.appletalk Subject: Re: Remote Bridge at full Appletalk speed? Message-ID: <25063@coherent.com> Date: 17 May 89 05:42:33 GMT References: <4316@ucdavis.ucdavis.edu> Reply-To: dplatt@coherent.com (Dave Platt) Followup-To: comp.sys.mac Organization: Coherent Thought Inc., Palo Alto CA Lines: 36 In article <4316@ucdavis.ucdavis.edu> lgdemichillie@ucdavis.edu (Greg DeMichillie) writes: > I was wondering if anyone knew of a Appletalk bridge that supports speeds of > over 19.2 K baud. We are going to be running our existing Appletalk > network to a remote site over a microwave link and it would be nice to not > bottleneck the Appletalk system with a 19.2K baud modem bridge. Actually, > something that support the full 230K baud would be preferred. Hmmm. I haven't seen any asynch-based half-bridges that will push bits anywhere near that fast... async runs out of steam at about 56 kbits/sec, and the fastest halfbridges I've seen mentioned don't seem to run their serial ports at over 19200 bits/sec. If your microwave link has a _very_ high bandwidth, I suppose you could use a Kinetics FastPath (KFPS-4 perhaps) at either end of the link, and push bits across the bridge at EtherNet speeds. At 10 megabits/second, I doubt that the bridge-to-bridge protocol would be the bottleneck! I suppose what you really need is a LocalTalk halfbridge that talks T-1 speeds between the halfbridges... T-1 microwave links are (I'm pretty sure) an off-the-shelf item, and the bandwidth of a T-1 link exceeds that of a LocalTalk net by a comfortable margin. I haven't heard of any such halfbridges, though. Maybe a pair of FastPaths, plus a pair of T-1 EtherNet half-bridges? Not cheap, I'm afraid. At last January's MacWorld Expo in San Francisco, I saw a company offering a digital-packet-radio-based LocalTalk bridge. Range was about 4 miles, as I recall... cost was in the $5000 range for a pair of transceivers. I didn't save the literature, I'm afraid. -- Dave Platt FIDONET: Dave Platt on 1:204/444 VOICE: (415) 493-8805 UUCP: ...!{ames,sun,uunet}!coherent!dplatt DOMAIN: dplatt@coherent.com INTERNET: coherent!dplatt@ames.arpa, ...@uunet.uu.net USNAIL: Coherent Thought Inc. 3350 West Bayshore #205 Palo Alto CA 94303