Thanks for taking the trouble to comment on my blog post.
You are correct that cwnd unit is indeed in packets.
And the mss of a loopback connection is, as you say, 32K. But here we are concerned not with connecting to other processes on the same server, but routing across the WAN to the other side of the globe. And unfortunately, unless we are
able to enable jumbo frames, we are stuck with the historical relic of 1500
packet sizes. This means that the initial congestion window size of only 15K.
Thanks for correcting my error about cwnd units. I'll fix the post later today.
No problem! Agreed that restart from idle is a little dumb especially with connections that go idle all the time. IMO whatever timer it uses should be in minutes not round trips.
Thankfully newer congestion control algorithms like BBR (which you can enable, though linux currently ships an older version) do not suffer from this and do not go to slowstart.
Thanks for taking the trouble to comment on my blog post. You are correct that cwnd unit is indeed in packets.
And the mss of a loopback connection is, as you say, 32K. But here we are concerned not with connecting to other processes on the same server, but routing across the WAN to the other side of the globe. And unfortunately, unless we are able to enable jumbo frames, we are stuck with the historical relic of 1500 packet sizes. This means that the initial congestion window size of only 15K.
Thanks for correcting my error about cwnd units. I'll fix the post later today.