Hi Max, Note how whenever acks go from 192.168.0.1 to 192.168.0.200, the window is constantly 8k, it never drops, i.e., that buffer never fills. If you pick a segment, say seq 18825 -> 20273, it’s sent at time 0.000545 and it’s acked at 0.000570. So, the ack went out after 25us and by that time the data was already consumed (since the window didn’t change)? In other cases, you can see it ack bursts of 4 packets (so 5792B) in ~40us.
Therefore, is the data read by the application much faster or is the advertised rcv window unrelated to the amount of data buffered? Obviously, if the latter, the actual buffer is larger than what you’ve configured. Also, does mtcp act as proxy in this case as well? Florin > On Jul 24, 2019, at 11:38 AM, Max A. via Lists.Fd.Io > <max1976=mail...@lists.fd.io> wrote: > > Hi Florin, > > > > Well, the question there is how large are the rx buffers. If you never see a > zero rcv window advertised to the sender, I suspect the rx buffer is large > enough to sustain the throughput. > > Using the reference [1], you can view a dump of downloading the same file > from the same linux server using the mtcp host stack (buffer size has been > set to 8192 bytes). As you can see from the dump, there is no one buffer > overflow. And in this case, even using an 8k buffer, we get good bandwidth. > > Thanks. > > [1] https://drive.google.com/open?id=15-sEAQ5BVCVgi36pqXD3cRX_mUxRk9r1 > <https://drive.google.com/open?id=15-sEAQ5BVCVgi36pqXD3cRX_mUxRk9r1> > > -- > Max A. > -=-=-=-=-=-=-=-=-=-=-=- > Links: You receive all messages sent to this group. > > View/Reply Online (#13573): https://lists.fd.io/g/vpp-dev/message/13573 > <https://lists.fd.io/g/vpp-dev/message/13573> > Mute This Topic: https://lists.fd.io/mt/32582078/675152 > <https://lists.fd.io/mt/32582078/675152> > Group Owner: vpp-dev+ow...@lists.fd.io <mailto:vpp-dev+ow...@lists.fd.io> > Unsubscribe: https://lists.fd.io/g/vpp-dev/unsub > <https://lists.fd.io/g/vpp-dev/unsub> [fcoras.li...@gmail.com > <mailto:fcoras.li...@gmail.com>] > -=-=-=-=-=-=-=-=-=-=-=-
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