#DIGA!
2 messages in this thread
Don, Sorry if I have confused anyone. It seems that I came in on this
discussion without reading all of the messages that were posted. The point I
was trying to get across was simply that Doubletalk _does_ do error checking on
each block, it just does not have to ACK/NAK each block. Sorry for any
confusion as to Compuserve's protocols that I might have caused.
Rocky Stargel
Rapid Software Systems/Aegis Development
Rocky,
No problem, I just wanted to make sure that folks knew what was being
discussed dealt with 2 computers using your program rather than someone using
your program and connected to CIS.
BTW, you can do essentially the same thing here on CIS but you have to
"cheat" the system to do it. On a download, you send 2 ACK's for the first
block only timed about 2 seconds apart. On an upload, you wait until the first
ACK is received, but don't remove it from the input buffer (again, only with
the first block). You then (either direction) have "pre-ACKed" the next block
and the transfer proceeds about 50% faster. The obvious danger is that IF an
error occurs, you cannot recover as you won't (or CIS won't) receive the NAK
until the block after the bad block. About 99% of the up/down loads work fine
this way, the time savings makes up for the occasional failed up/download, but
it's hard to explain to users…so it's a risky proposition.
Don