🚀 go-pugleaf

In article <310635dd.0@sylvia.tummy.com>, jafo@ariel.tummy.com (Sean Reifschneider) writes:
|> Limited by the speed of the Linux serial port?  Why?  I mean, we're not talking
|> T1 speeds here, we're talking 56/64K or possibly 115/128K.  These ARE speeds
|> that can be handled by the serial ports with the exception of 128 (which
|> you'd have to run at 115.2K).  I've been running my 64K ISDN line at 115K
|> for months now with 0 problems.

  The rate on the ISDN line is sync, i.e., without start/stop bits,
while the serial port is async, which requires one start and one stop
bit per character.  This implies your serial port can transfer
115,200/10 or 15,200 bytes/second, while the phone line transfers
128,000/8 or 16,000 bytes/second.  You loose 800 bytes/second.

  And how can you take advantage of compression when your serial port
already runs slower than the bit rate?  You cannot.  On my 1B Pipeline
50 connection I see ftp rates in excess of 7,000 bytes/second, so
compression helps by, say, at least 10%.

  That's why some of us talk about the serial port limiting throughput.

|> Sean

    Bob
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