[e2e] end2end-interest Digest, Vol 52, Issue 10

[S. Keshav]

Maybe I'm being really dumb, but I think that the reason for rwnd is  
simple: why should a sender bother sending something if there is no  
place to keep it when its received? By telling the sender how much  
buffer space it has left, the receiver avoids dropping data that has  
been sent over the network, which represents wasted effort. One could  
argue that the rwnd value should really be a predictor for the buffer  
capacity that is expected to be available one RTT from now, but  
setting that quibble aside, there isn't much more to it.

keshav