do not use error correction or compression. (they will slow you down)
huh?!? my file transfer times would *double* if i turned off v.42bis (modem compression). *that* would slow me down. and you can't run v.42bis without running the error handling protocol (v.42), for obvious reasons. what's more, v.42 gives an immediate 20% (or so) increase in throughput, by eliminating start and stop bits. arguably, i could (and should) be running compression in my slip or ppp driver, but certainly it is false to say that v.42bis and v.42 slow me down -- the opposite is true.
and tcp does it's own error correction. as for 160ms round trip times that is acceptable for slip.
i don't much care about round-trip times, as i use my slip line principally for afs, which runs as a data stream. round-trip delays are amortized over file transfers. phil karn's points about modem buffering interfering with type-of-service queueing are the strongest condemnations of modern modems, in my view. i wish someone would build a modem that recognized ip packet framing. peter