This stack was developed by my colleagues at Netflix (primarily Randall Stewart, known for SCTP). It serves the vast majority of our video and other CDN traffic.
Interesting, didn’t know that FreeBSD has this feature.<p>I know of one other operating system which has a somewhat similar feature, but not quite the same. z/OS supports running multiple TCP/IP stacks concurrently on the same OS instance [0]<p>Whereas this is multiple TCP stacks, but still only one IP stack (or maybe one for v4 and one for v6)<p>[0] <a href="https://www.ibm.com/docs/en/zos/2.2.0?topic=overview-considerations-multiple-instances-tcpip" rel="nofollow">https://www.ibm.com/docs/en/zos/2.2.0?topic=overview-conside...</a>
I'm having trouble parsing the following passage.<p>>"However, when the loss is at the end of a transmission, near the end of the connection or after a chunk of video has been sent, then the receiver won’t receive more segments that would generate ACKs. When this sort of Tail loss occurs, a lengthy retransmission time out (RTO) must fire before the final segments of data can be sent."<p>I believe this whole passage is just describing TCP fast retransmit vs a retransmit timeout expiring. However if the final TCP segment from the sender is lost wouldn't the receiver also start sending duplicate ACKs as well? This sentence seems to indicate duplicate ACKs would not be sent if the last segment was the TCP segment that was lost. In other words a duplicate ACK from the receiver is lost and so the RTO expires.
TIL that Linux has pluggable congestion control algorithms.<p>Anyone know if there's one that can deal with severe buffer boat? I have a connection where I control both ends and I have seen ping times exceed 20s under load. Throughput is highly variable so I can't just throttle the connection.