NFD

What's the exact putchunks and catchunks commands you ran?

The bandwidth-delay product is 10Gbps * 3ms = 30Mb = 3.75MB. The congestion window cannot be bigger than this, which means for a 1MB packet size, the congestion window should be at most 3.75 packets. The initial window size of 500 is too big. Or you have a different definition of window? It usually means the number of outstanding packets.

Hey Susmit, I think you should retry your measurements with the very latest version of NFD and ndn-tools. It includes two improvements:

• The basic congestion control scheme works now (on UDP, TCP, and Unix sockets)
• Ndncatchunks can run without printing a line per packet, which makes it faster.

I can get better performance using normal-sized chunks (4KB):

klaus@Latitude-E7470:~$ ndncatchunks --aimd-ignore-cong-marks /bla > /dev/null

All segments have been received.
Time elapsed: 2582.85 milliseconds
Total # of segments received: 23676
Total size: 104174kB
Goodput: 322.662441 Mbit/s
Total # of retransmitted segments: 2222
Total # of received congestion marks: 152
RTT min/avg/max = 0.875/45.972/329.765 ms

I get even better performance when using the congestion marks:

ndncatchunks /bla > /dev/null

All segments have been received.
Time elapsed: 1285.99 milliseconds
Total # of segments received: 23676
Total size: 104174kB
Goodput: 648.052707 Mbit/s
Total # of retransmitted segments: 0
Total # of received congestion marks: 9
RTT min/avg/max = 0.847/17.817/174.590 ms

Davide Pesavento wrote:

Klaus Schneider wrote:

• The basic congestion control scheme works now (on UDP, TCP, and Unix sockets)

Remember that the above still requires changing a flag in NFD's source code. You can wait for #4465 if you don't want to do that.

Which flag should I change?

susmit shannigrahi wrote:

Davide Pesavento wrote:

Klaus Schneider wrote:

• The basic congestion control scheme works now (on UDP, TCP, and Unix sockets)

Remember that the above still requires changing a flag in NFD's source code. You can wait for #4465 if you don't want to do that.

Which flag should I change?

In the GenericLinkService::Options constructor, you can change allowCongestionMarking to true.

Eric Newberry wrote:

In the GenericLinkService::Options constructor, you can change allowCongestionMarking to true.

Yeah, plus remember to do that for all involved hosts.

why --aimd-ignore-cong-marks?

Davide Pesavento wrote:

why --aimd-ignore-cong-marks?

Yeah, using the congestion marks (removing the --aimd-ignore-cong-marks option) should give you an even higher performance.

Can you post the catchunks summary output? I'm especially interested in #retransmissions and RTT.

In the GenericLinkService::Options constructor, you can change allowCongestionMarking to true.

Thanks, Eric.
I noticed that you merged a change that incorporates the config file option. So this is no longer need, right?

susmit shannigrahi wrote:

In the GenericLinkService::Options constructor, you can change allowCongestionMarking to true.

Thanks, Eric.
I noticed that you merged a change that incorporates the config file option. So this is no longer need, right?

Correct. We're planning to add this to management soon as well.