[e2e] Question on TCP throughput and host's access speed

[Xiaoliang (David) Wei]

Hi Jing,

> But, what makes me confused is : if TCP modifies its
> sending window according to ACK received,and
> bottleneck link would not distinguish between ADSL
> subscribers and Fiber  link subscribers, no matter how
> asymetric is routing path or how much difference
> between access line,  TCP on both end should behave
> similar (?). Why there exist so much difference ?
    If the return path suffers packet loss, there may be ack compression and 
introduce more bursty sending traffic, due to TCP window control. Then you 
may see packet loss (or NIC queue overflow) in your local machine -- before 
getting to the access point. And the buffer on the ADSL interface may be 
larger than the buffer on the fiber interface.
    If you are using Linux, it will be good to have a web100 patch to get 
some statistics. Then you will probably find more conclusive answers.

-David