2) Ian - In section 4.3 of RFC3448 we have the equation for X as:
If (p > 0)
Calculate X_calc using the TCP throughput equation.
X = max(min(X_calc, 2*X_recv), s/t_mbi);
I have been doing experiments where I deliberately drop real-time
packets when I don't believe they will get to the other end before an
expiry time. What happens though is that I can't then transmit packets
later on due to the above equation as in practice it becomes
X=2*X_recv and X_recv quickly goes close to 0 as it is the receive
rate since last feedback. Feedback gets sent once per RTT I think and
so if you don't send anything for one RTT you get X=s/t_mbi in effect
which is 530/64 for my size packets - i.e. a sending rate of 10 bytes
per second. In practice I don't get quite this bad as I don't drop off
transmitting that long usually but I still definitely get penalised.
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