Internet upload connection requirements

[pshd21]

It seems like there is too much uploaded in FA games.
My internet connection can handle about 70 kB/s up and 700 kB/s down. I guess that's too low for 12 players, what is actually really sad because on another rts I play 10p games with a 50 kB/s modem speed, where I don't even notice any lags or desyncs at all (Max 10 kB/s down, no p2p).
Anyone knows what is sent all the time, that it requires so much traffic? This gets especially noticeable on the beginning of games.
My ping spikes from 100 to 800 constantly on 12p games.