Incast Experiment

[ChengjunJia]

Hello, I want to repeat the incast experiment in the PowerTCP paper.
The result of 10-1 incast fits well with the paper, but when I add more flows (I tried the 96-1 incast), the result is different from the paper (the queue is about 100KB-200KB after coverage).

The flows I use are:

97
0 16 3 10000 1000000000000 0.13
32 16 3 10001 1000000000000 0.15
33 16 3 10033 1000000000000 0.15
...
127 16 3 10127 1000000000000 0.15

Is there any problem with my experiment? In the paper, you say

in addition to the 10 : 1 incast, the 256th server sends a query request (§4.1) to all the other 255 servers which then respond at the same time, creating a 255:1 incast.

How can I create the experiment?

[vamsiDT]

Hi,

The 255:1 incast scenario is composed of (4 long flows if I remember correctly) and a query request that generates 255 flows (you would need 255 short flows approx 4K bytes in size). Launching 255 long flows (building up 255BDPs of buffer) is an extreme case where no congestion control algorithm cannot do any better, given the small buffer size.

Hope it is clear.

[ChengjunJia]

I got it. Thanks very much :)