•After a loss it can take over an
hour for stock TCP (Reno) to recover to maximum throughput at
1Gbits/s
–i.e. loss rate of 1 in ~ 2 Gpkts
(3Tbits), or BER of 1 in 3.6*1012
–
•PCI bus
limitations (66MHz * 64 bit = 4.2Gbits/s at best)
•At 2.5Gbits/s
and 180msec RTT requires 120MByte window
•Some tools
(e.g. bbcp) will not allow a large enough window – (bbcp limited to 2MBytes)
•Slow start
problem at 1Gbits/s takes about 5-6 secs for 180msec link,
–i.e. if want 90% of measurement in stable (non slow
start), need to
measure for 60 secs
–need
to ship >700MBytes at 1Gbits/s