4 ms·
I do not understand the point you are trying to make. The person you replied to showed how to evaluate it with simple math. 400 Gb/s is 50 GB/s. RTT of 300 ms
by Veserv 7mo ago
I do not understand the point you are trying to make. The person you replied to showed how to evaluate it with simple math.
400 Gb/s is 50 GB/s. RTT of 300 ms would only require 15 GB of buffers. That would not even run a regular old laptop out of memory let alone a server driving 400 Gb/s of traffic. That would be single-digit percents to possibly even sub-percent amounts of memory on such a server.
- fulafel 7mo agoI introduced the concept of bandwidth * delay product to the conversation... The question was about why use dynamic allocation. In this branch of the thread we ere discussing the question "Are there TCP/IP stacks out there in common use that are allocating memory all the time?" We'd not be happy to see the server or laptop statically reserving this worst-case amount of memory for TCP buffers, when it's not infact slinging around max nr of tcp connections, each with worst-case bandwidth*delay product. Nor would be happy if the laptop or server only supported little tcp windows that limit performance by capping the amount of data in-flight to a low number. We are happier if the TCP stack dynamically allocates the memory as needed, just like we're happier with dynamic allocation on most other OS functions.