syndrome avoidance. The combination of SWS avoidance and ack-every-other
causes low throughput if the block size divided by the MSS is odd (which
is true with the default block size and MSS).
Turning on TCP_NODELAY disables the Nagle algorithm and sender SWS avoidance.
The rdump request/response protocol can not invoke Nagle and cannot cause
SWS, so this has no negative effects.
options one would normally expect to set the realm, enable encryption,
and whatnot, but this actually is able to contact the remote server,
so at least it's a start. (As a bonus, the stripped static binary is
unquestionably exportable.)
setsockopt()'s on a -1 file descriptor.
Remove attempt to decrease TCP MSS; it makes no sense.
Set the IP TOS to IPTOS_THROUGHPUT as an indication that this is an
application sending large blocks of data, as recommended by RFC1700.
changes and one addition by me.
. Use reasonable defaults for the tape drive (/dev/rst0) instead of
something we actually don't have.
. Add a summary line displaying the alapsed time and the total throughput.
. Replace "rmt" for the remote location of rmt(8) by "/etc/rmt", since this
is the historical protocol, and relying on the $PATH causes a big pain.
Make it adjustable via an environmental variable though.
Reviewed by: joerg (for Andreas' part)
Submitted by: andreas@knobel.gun.de (Andreas Klemm)