WAN thruput conclusions
High FTP performance across WAN links is possible
- Even with 20-30Mbps bottleneck can do 100Gbytes/day
OS must support big windows selectable at application level
Need multiple parallel streams & large windows
Multi streams more effective than big windows
Loss is important in particular interval between losses
- e.g. need ~ 104 packets for 200ms RTT & 20Mbits/s link (~W2)
Compression looks promising, but needs lots of cpu
Impact of high thruput is noticeable
- mainly in RTT
- less so for loss (thank goodness)
- need way to minimize effect (e.g. scavenger type QoS)