[netperf-talk] PAD_TIME in 2.4.5

[Srikanth Sundaresan]

We faced some issues using netperf 2.4.5 on low bandwidth networks.

The recv() call was getting interrupted by a SIGALRM; we figured it's caused by low values of PAD_TIME. Our guess is that with high buffering in modems the delays (multiple seconds) is causing a timeout. This only occurs on upstream tests and not on downstream tests (presumably because the data rates are higher, and so buffering is lower). 

We *kind of* fixed this by setting higher values of PAD_TIME - it seems to work better with ~30 seconds (our tests are 15 seconds long). We have two questions regarding this fix:

1) Will higher PAD_TIMEs affect test accuracy?
2) Do we need to patch the client too? Currently we test both sides by running -t TCP_STREAM and -t TCP_MAERTS respectively; does the client time out too?

Thanks,
Srikanth