jms@vanth.UUCP (Jim Shaffer) (03/20/91)
In article <mac1.669336994@Ra.MsState.Edu> mac1@ra.MsState.Edu (Cheema) writes: > > I wonder if its only me or everybody else is in the same boat. I have a 1200 >baud modem and when I am downloading some long files say around 400k it makes >me wait for hours (normally 4 to 6 hrs). I have ordered another 2400 baud >modem but still I think I still will have to wait at least a couple of hours >for a file to get downloaded. Is this weird or normal ? > I am currently using Xmodem protocol. Does terminal program has any effect on If you're actually getting 120 cps over a 1200 bps connection (which you WON'T be if you use Xmodem, because it's the worst thing you can use!) simple math shows that a 400000 byte file will take 55 minutes to download. (At 2400 baud it will take 27 minutes of course.) Even with Xmodem's horrible throughput (I think I got about 1800 baud over a 2400 baud link when I was forced to use it once) you shouldn't be taking 4 to 6 hours. You must have a very noisy line. (Or a very busy system on the other end.) Does whatever program you're using give you any indication of how many times it's re-trying a packet (or how many times it's timing out?) The best thing in common use is Zmodem, in my experience. I can get AT LEAST 230 cps on a clean 2400 bps link, and that's with floppies too. -- * From the disk of: | jms@vanth.uucp | "Speeding through the Jim Shaffer, Jr. | amix.commodore.com!vanth!jms | universe, Thinking is 37 Brook Street | uunet!cbmvax!amix!vanth!jms | the best way to travel." Montgomery, PA 17752 | 72750.2335@compuserve.com | (The Moody Blues)
frank@morpheus.UUCP (Frank McPherson) (03/20/91)
In article <1991Mar19.215425.9317@sbcs.sunysb.edu> dtiberio@csserv2.ic.sunysb.edu (David Tiberio) writes: > At 2400 baud, expect twice the above cps, with a max zmodem of about 240 cps. >At most I have gotten 280 cps xmodem and 1760 cps with ymodem (at 19200 baud). >Always avoid Kermit (really slow). > > Always try to use zmodem, or then try ymodem. They are 30% faster and more >reliable. If a file is over 800k, then it can be split if it is a disk >compressor. If it is a normal archive, then only decompress enough to fit >in each disk (or all of it in ram). > > David Tiberio SUNYStonyBrook2-3481 DDD MEN > isOP -- One of the main reasons Xmodem and Kermit are so slow compared to Y and Z modem is that Xmodem and Kermit normally have a very small packet size, while Y and Zmodem have larger (1 K) packet size. The normal size packet for Kermit is something around sixty bytes, so you end up having a transfer where the time to transfer is dominated by the protocal handshake, instead of by the actual transfer of data. Same problem, to a lesser extent, with Xmodem. With some versions of Kermit, you can make the problem less obvious by instructing both ends of your transfer to use larger blocks. When using Xmodem, either try Xmodem with 1K blocks, or use a different protocal. -- Frank McPherson INTERNET: emcphers@fox.cs.vt.edu --