caroma@wheat-chex.ai.mit.edu (Carl R. Manning) (11/19/90)
In article <86@ar-rimal.cs.utexas.edu> garnett@cs.utexas.edu (John William Garnett) writes: >During my downloads using zmodem I found that it achieved about 225 to 230 >characters per second using a 2400 baud modem. This is a whole lot better >than the 78 or so that kermit typically achieves. The 78cps indicates that you were probably running kermit with very suboptimal protocol settings. I have found that in using kermit to transfer to a Mac over 9600 baud modem, to get decent performance I had to change the blocksize from its default of around 90 chars, to something around 700-800 chars. I think I also changed the size of the sliding window, which determines how many blocks the sender may get ahead of the receiver's acknowledgements; the default is around one block, which means the sender must wait for the acknowledgement after each block sent before sending the next. The settings will be different for 2400 baud. You may be satisfied with rz/sz and tip, but I thought I'd let others know it's possible to get decent performance with Kermit. Kermit on the Mac shows you the transfer rate in progress, so it is relatively easy to optimize protocol settings by aborting a transfer and adjusting the settings a few times. I don't know whether an equivalent interface for NeXT Kermit exists. -- CarlManning@ai.mit.edu