Re: [iccrg] AIMD versus AIAD

[Jana Iyengar <[e-mail]>]

Jonathan,

MD:  O(1) signals causes O(N) reduction in cwnd.


That's not quite right. MD refers to a multiplicative reduction in the rate
or window _per RTT_. That is, the reduction in the window is f(window).
That's a critical aspect of the definition of all these terms. This goes
all the way back to Chiu and Jain
<https://www.cse.wustl.edu/~jain/papers/ftp/cong_av.pdf>.


> Conversely, looking at DCTCP and ignoring the low-pass filters which
> disappear in the long run, each CE mark causes half a segment to be
> subtracted from the cwnd.  This is classic Additive Decrease.


For the same reason, this is not correct. Presumably, since the number of
CE marks are f(window), I would argue that the reduction _over an RTT_ is
f(window). That makes this MD, not AD.

- jana