Xref: utzoo comp.dcom.modems:3989 comp.mail.uucp:3272 Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!cwjcc!hal!ncoast!allbery From: allbery@ncoast.ORG (Brandon S. Allbery) Newsgroups: comp.dcom.modems,comp.mail.uucp Subject: Re: Telebits and uucp g-protocol Message-ID: <13751@ncoast.ORG> Date: 13 Jun 89 23:56:28 GMT References: <335@nixtor.UUCP> Reply-To: allbery@ncoast.ORG (Brandon S. Allbery) Followup-To: comp.dcom.modems Organization: Cleveland Public Access UN*X, Cleveland, Oh Lines: 29 As quoted from <335@nixtor.UUCP> by davidm@nixtor.UUCP (David Macklem): +--------------- | I have a number of questions about Telebits and the g-protocol | spoofing that they do. Hopefully someone out there will explain. | | I understand that the Telebit TB+ modems can do the uucp g-protocol | between themselves. This ability sure is nice but it doesn't really | offload the CPU that much, does it? The sending and receiving machines | still need to packetize/unpacketize and checksum the data, etc., ie. +--------------- Telebits do *not* use 'g' protocol between themselves; they use PEP. What happens in the protocol recognition mode is that UUCP (or Xmodem or Kermit) sends its packets to the Telebit as usual. The Telebit then *strips* the protocol and sends the packets via its usual PEP encoding. The remote modem then re-assembles the packets into valid UUCP (Xmodem, Kermit) packets for the remote computer. Why? Because layering two packet protocols on top of each other guarantees throughput problems. Telebit, by special-casing common protocols, avoids this transparently. ++Brandon -- Brandon S. Allbery, moderator of comp.sources.misc allbery@ncoast.org uunet!hal.cwru.edu!ncoast!allbery ncoast!allbery@hal.cwru.edu Send comp.sources.misc submissions to comp-sources-misc@ NCoast Public Access UN*X - (216) 781-6201, 300/1200/2400 baud, login: makeuser