Raise initial congestion window size / speedup slow start?

[Ed W <lists@wildgooses.com>]

Hi, my network connection looks like 500Kbits with a round trip latency 
of perhaps 1s+ (it's a satellite link).

 From what I can see the linux initial congestion window is signficantly 
limiting me here, with slow start taking many many seconds to open up 
the window wide enough to get the data flowing?  For protocols like http 
this is really hurting with all the short lived connections never really 
getting up to speed.  (throw in some random packet loss and things 
really screech to a halt)

Reading around there appear to be several previous attempts to modify 
the kernel to start with a slightly wider initial congestion window, say 
10 packets.  (Seems even google did some work on this and agreed that a 
small of initial cwd to 10 ish, would help even many non satellite 
users?) However, all the work I can find is quite old and doesn't seem 
to give me much of a leg up in terms of experimenting with such changes 
on a modern kernel?

Does someone have some pointers on where to look to modify initial 
congestion window please?


Thanks

Ed W