Different throughputs in two directions

Edwin Law (e-law@cs.yorku.ca)
Tue, 23 Jun 1998 17:14:44 -0400 (EDT)

I wonder if anyone has an explanation why I sometimes get different
throughputs of data transfer in the two directions? For example, here
are some average throughputs I got from the FTP program on the Sun's.
Both the server and client are using the same socket buffer size and
application data buffer size. No file cache was present. The results are
significantly different for the smaller files.

File size (get) (put)
5120 0.763618 2.57051
51200 4.10513 3.48977
512000 7.06257 7.40242
5242880 8.44075 8.52563
52428800 8.45311 8.51249

Should Netperf also include some kind of "server's side" timing, like
TTCP does?

Thanks in advance,