v11i020: Idle demon

[William Lewis]

In article <L3VFo1w162w at cybrspc> cybrspc!roy at cs.umn.edu (Roy M. Silvernail) writes:
>Now, the question in my mind (and this really has nothing to do with the
>original thread :-) is... which type is SEAlink? I have used it on
>several systems, and had varying results. In some cases, it has behaved
>as a streamer (with no activity seen on the alternate-channel modem
>light), and sometimes it's acted like a sliding-window, if not downright
>packetized.

   Well, last I checked, SEAlink was a very lightly modified XMODEM (CRC)
and sliding window. Basically, the ACK/NAK byte was expanded to a 
very small (3 or 5 byte) packet containing the last valid packet received.
The window size defaulted to something on the order of 6 XMODEM packets.
I have no idea why it wouldn't show activity on the return channel; maybe
the modem light flickered too briefly for a packet only 5 bytes long?
Or maybe the protocol has been updated since I looked at it, though
I doubt it.

  [Note also that using SEA products is sometimes considered politically
incorrect, after SEA sued PKWare ... though, SEAlink *is* a nice clean
protocol .. and this doesn't belong in this group anyway.]


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