Reading the source, I noticed that the data that NDT sends in S2C and C2s tests
is nonrandom.
From the Flash client:
// Prepare the data to send to the server.
for (var i:int = 0; i < NDTConstants.PREDEFINED_BUFFER_SIZE; i++) {
_dataToSend.writeByte(i);
}
https://code.google.com/p/ndt/source/browse/trunk/flash-client/src/TestC2S.as#16
8
From the C client:
// ....Fill buffer upto NDTConstants.PREDEFNED_BUFFER_SIZE packets
pkts = 0;
k = 0;
for (i = 0; i < (64*KILO_BITS); i++) { // again buffer sizes differ.
// Since the actual transmitted byte count is timed, it doesn't appear
// that it is causing specific problems.
while (!isprint(k & 0x7f))
k++;
buff[i] = (k++ % 0x7f);
}
https://code.google.com/p/ndt/source/browse/trunk/src/test_c2s_clt.c#141
Because we're sending buffers of sequential bytes (and in the case of the C
client, only printable ASCII characters), there is a risk that boxes on the
network will compress the data and skew measurements.
We should modify the code for data generation so that we use a pseudorandom
number generator with a periodicity of at least 64k, then take the last byte of
each generated number as the next byte to place in the send buffer.
Original issue reported on code.google.com by mtly...@google.com on 6 Oct 2014 at 9:06
Original issue reported on code.google.com by
mtly...@google.comon 6 Oct 2014 at 9:06