pete@saturn.ucsc.edu (Peter Hughes) (03/16/91)
I have a telebit T2500 9600-baud modem. I dial into a Unix network using VersaTerm Pro. Kermit gives me a transfer rate of about 30 bytes/sec, less than 3% of line capacity. Xmodem crashes. My question-- what is the best software combination on both ends for talking over 9600-baud from a Mac II to a unix network? Peter pete@saturn.ucsc.edu
shwake@raysnec.UUCP (Ray Shwake) (03/17/91)
pete@saturn.ucsc.edu (Peter Hughes) writes: > I have a telebit T2500 9600-baud modem. I dial into a Unix >network using VersaTerm Pro. Kermit gives me a transfer rate of about >30 bytes/sec, less than 3% of line capacity. Xmodem crashes. The two modems may be "optimized" for different protocols, thus giving lower performance than would be the case without such optimization. Check out register S111. I have one modem set to S111=30 for UUCP transfers, only because my News counterpart sets his to 255. If I call into my modem from another Telebit and run kermit file transfers, throughput drops substantially (from ~875 to ~160). ----------- uunet!media!ka3ovk!raysnec!shwake shwake@rsxtech
gandrews@netcom.COM (Greg Andrews) (03/17/91)
In article <13477@darkstar.ucsc.edu> pete@saturn.ucsc.edu (Peter Hughes) writes: > > I have a telebit T2500 9600-baud modem. I dial into a Unix >network using VersaTerm Pro. Kermit gives me a transfer rate of about >30 bytes/sec, less than 3% of line capacity. Xmodem crashes. > Sounds like you're making the connection using the Telebit PEP modulation, but you're not turning on the Xmodem or Kermit protocol support. Without protocol support enabled for the transfer protocol, transfers are extremely slow. Check the description of the S111 register in Chapter 5 of the modem's manual. Turning Kermit support on usually requires S111=10, turning on support for Xmodem and Ymodem requires S111=20. The modem can only enable support for one protocol at a time, so you need to decide which one you want to use and set the register before you call. Kermit is probably a little bit better than Xmodem and Ymodem because of the features it has. With the modem's protocol support turned on, Kermit will run just as fast as Xmodem or Ymodem, so there's no disadvantage in speed. Choose the protocol that has the features you like best, turn on support for that protocol in the modem, and transfer the files. -- .-------------------------------------------. | Greg Andrews | gandrews@netcom.COM | `-------------------------------------------'
squishy@casbah.acns.nwu.edu (Shishin Yamada) (03/17/91)
I have a Mac IIsi with a Practial Peripherals 9600SA (used to be
attached to my SE/30). I've encountered a lot of problems with file
transfers with our Sun Sparc station and finally resolved a lot of them
(some fixes were permanently installed by the sys admin). I found out very
quickly that Kermit seems to be the slowest transfer protocol of all. Right
now I typically use Zmodem because it is quick and dirty. X and Y modem
are also good protocols, but I optimized my setup for Zmodem. If you have
similar setups, you might have similar problems, is all I can say.
I don't know exactly why your Kermit transfers are at only 3% of
true value. That is odd. I wouldn't know how that would happen, other than
maybe you have a speed bottleneck somewhere. I have a max transfer rate of
38,400 bps, but realistically I only get up to 9600 bps due to a speed
bottleneck imposed on our system. Our system is set up through a dial-in
unit that is connected to a gateway that operates at only 9600 bps, so in
my case I often see 25% efficientcy (25% at 38,400 bps = 9600 baud) and
this is normal. I've complained to the sys admin to speed things up at our
university and he said 'it was in the works.'
In our BSD 4.2 unix, there are nice features of X/Y/Zmodem that are
implemented. If you have access to these and your transfers are hanging up
on you it could be because of the Xon/Xoff handshaking going on. This
happens cheifly with MacBinary files. Text files don't pose problems to
software handshaking, and don't barf. If this is the case, I think there is
a command called Zmodem -e <filename>. The -e option will Escape all
Xon/Xoff characters. This worked for me, but slowed transmissions. Later,
the sys admin changed this.
I know this isn't much, but I hope it helps.
=====================================================
Shishin "Squish" Yamada |\/\/\/|
squishy@casbah.acns.nwu.edu /---------\ | |
Northwestern University | Yo | (o)(o) |
Electrical Engineering | Dudes! \ ( < )
Class of 1991 \__________\ |___/ |
\ |
"Life sucks, but Death swallows!" / \
/______\
=====================================================allbery@NCoast.ORG (Brandon S. Allbery KB8JRR) (03/21/91)
As quoted from <28588@netcom.COM> by gandrews@netcom.COM (Greg Andrews): +--------------- | In article <13477@darkstar.ucsc.edu> pete@saturn.ucsc.edu (Peter Hughes) writes: | > I have a telebit T2500 9600-baud modem. I dial into a Unix | >network using VersaTerm Pro. Kermit gives me a transfer rate of about | >30 bytes/sec, less than 3% of line capacity. Xmodem crashes. | > | | Sounds like you're making the connection using the Telebit PEP | modulation, but you're not turning on the Xmodem or Kermit protocol | support. Without protocol support enabled for the transfer protocol, | transfers are extremely slow. +--------------- Telebit configuration hint: set the modem for S111=255 and for reset on loss of DTR. Then have the dial-out script set the protocol to be used *on dialout*. (Assumes BNU UUCP; g*d knows if the BSD folks have gotten over their bout of NIH syndrome yet and come up with a way to do this.) The machine I use at work has separate service=uucp and service=cu Dialers files; we set the modem for UUCP protocol on uucp dialouts and X/Ymodem on "cu" dialouts. (There are programs that can be used with cu's "~$" command. Also, I'm working on a program that will use the service=cu information. I'll be interested in seeing what breaks if I put a "service=qzt" in Sysfiles....) On the Mac, you are presumably dialing out; have your terminal program initialize the modem to Xmodem/Ymodem or Kermit (X/Y preferred, then use Ymodem; Zmodem works but may not be quite as well optimized), or save that setting in the modem. ++Brandon -- Me: Brandon S. Allbery Ham: KB8JRR on 2m, 220, 440, 1200 Internet: allbery@NCoast.ORG (QRT on HF until local problems fixed) America OnLine: KB8JRR // Delphi: ALLBERY AMPR: kb8jrr.AmPR.ORG [44.70.4.88] uunet!usenet.ins.cwru.edu!ncoast!allbery KB8JRR @ WA8BXN.OH