kim@mcrware.UUCP (Kim Kempf) (10/23/87)
Do these modems require any special modifications to the uucp software, or are they completely transparent?
honey@umix.cc.umich.edu (Peter Honeyman) (10/23/87)
the trailblazer requires no modifications to uucp. peter
sl@van-bc.UUCP (Stuart Lynne) (10/24/87)
In article <548@mcrware.UUCP> kim@mcrware.UUCP (Kim Kempf) writes: >Do these modems require any special modifications to the uucp software, or >are they completely transparent? More or less transparent. By more I mean that if the "S" registers are setup appropriately, i.e. connect in PEP mode, allow UUCP, data compression on, etc, then once the two modems see a uucp startup they will fake the the machines at each end into thinking they are talking to each other with the uucp "g" protocol. The modems then talk each other using Telebits proprietary PEP protocol. The modems have some amount of internal buffer (seems to be at least 8-16k) so a fair amount of buffering can take place at the sending end, which allows the modems to always work at full speed. By less I mean that the ideal "S" register settings for allowing outgoing and incoming PEP uucp calls may not be ideal for dialup/dialout uucp, and/or interactive traffic. So you may need to arrange to set the "S" registers appropriately for different types of uses which can be annoying depending on what system software you have. The biggest problem with mail traffic now seems to be the inter-file pauses. With typical small mail files, plus the X. files, you tend to have a couple of seconds (2-6, depending on system load etc) between each file. This can add up to an overhead which exceeds the actuall time to send the mail message. What we need is a simple method to bundle messages together into a "mailbag" for delivery. -- {ihnp4!alberta!ubc-vision,uunet}!van-bc!Stuart.Lynne Vancouver,BC,604-937-7532
david@elroy.Jpl.Nasa.Gov (David Robinson) (10/24/87)
I do not have a Trailblazer (yet), I wonder what command set does it use. I assume Hayes compatible, but is it Hayes 1200 or Hayes 2400 and how compatible is compatible? -- David Robinson elroy!david@csvax.caltech.edu ARPA david@elroy.jpl.nasa.gov (new) seismo!cit-vax!elroy!david UUCP Disclaimer: No one listens to me anyway!
butler@stsci.EDU (Lee A. Butler) (10/25/87)
in article <2451@umix.cc.umich.edu>, honey@umix.cc.umich.edu (Peter Honeyman) says: > > the trailblazer requires no modifications to uucp. > > peter But if you want to take advantage of the trailblazer's added speed, you want to use a transfer protocol that will allow large (1K-2K) data packets and a sliding-window ack scheme. These modems take about 2 sec to turn the transmission around. This would mean a 2 sec wait for the transmission of the ACK to every packet if you didn't have sliding-window ACK. The data compression done in some of these modems makes it beneficial to transmit data in large packets (since the modem is doing the re-trans you don't pay as high a penalty for this as you might think). -- Lee A. Butler butler@stsci.arpa | butler@brl.arpa Space Telescope Science Institute Usenet: {noao,nrao1}!stsci!butler 3700 San Martin Drive SPAN: SCIVAX::BUTLER (6405::BUTLER) Baltimore, MD 21218 Phone: (301) 338-4531
myers@andromeda.rutgers.edu (Scott R Myers) (10/26/87)
The Telebit Trailblazers do use the Hayes Command set and it seems to closely resemble that of the 2400 more so than the 1200. If you need a listing of the command set send mail and I'll get it to you...
chris@mimsy.UUCP (Chris Torek) (10/26/87)
>in article <2451@umix.cc.umich.edu> honey@umix.cc.umich.edu (Peter >Honeyman) says: >>the trailblazer requires no modifications to uucp. In article <54@stsci> butler@stsci.EDU (Lee A. Butler) writes: >But if you want to take advantage of the trailblazer's added speed, you want >to use a transfer protocol that will allow large (1K-2K) data packets and a >sliding-window ack scheme. That is so. Yet peter (that is the way he spells it) is correct. Somehow the Trailblazer manages to use large data packets and sliding window acks, even while uucp is talking to it using small data packets and sliding window acks. The trick is called `g protocol spoofing': The modem pretends to be the other computer, and acks UUCP's small packets before it has sent its own big packets. It may sound horrid, but it works well. -- In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7690) Domain: chris@mimsy.umd.edu Path: uunet!mimsy!chris
chandler@beagle.UUCP (Jim Chandler) (05/30/90)
Does anyone out there know what port and interrupt com3 and com4 are using on the Telebit trailblazer. I need it to attempt to add it as a third com port to ESIX and regain one of my built in com ports. Any telebit engineers read this newsgroup? Thanks in advance. -- Jim Chandler asuvax!xroads!beagle!chandler chandler@beagle.UUCP