How to enable ECN on CoDelQueueDisc or TcpSocketBase?

[Md Ashiqur Rahman]

I am on ns3 version 3.30 and trying to manually enable/disable the ECN. I have tried different ways to do so, but always end up with error. 

Please suggest how I can set enable/disable ECN properly (of course default is disabled).

Code: https://gist.github.com/ashiqopu/3b7d070119bee4c0f8d6cb51eb084a69

Here are some tries and errors:

// Try 1

Config::SetDefault ("ns3::TcpSocketBase::UseEcn", StringValue ("On"));

error:

msg="Could not set default value for ns3::TcpSocketBase::UseEcn", file=../../src/core/model/config.cc, line=815

// Try 2

Config::SetDefault ("ns3::CoDelQueueDisc::UseEcn", BooleanValue (true));

error:

msg="Could not set default value for ns3::CoDelQueueDisc::UseEcn", file=../../src/core/model/config.cc, line=815

// Try 3, out of frustration, pretty sure this is completely wrong:

TrafficControlHelper tchCoDel;
tchCoDel.SetRootQueueDisc ("ns3::CoDelQueueDisc");
tchCoDel.SetQueueLimits("ns3::CoDelQueueDisc", "UseEcn", BooleanValue (true));
// later used tchCoDel.install(<somenetdevice>);

error:

msg="Invalid attribute set (UseEcn) on ns3::CoDelQueueDisc", file=../../src/core/model/object-factory.cc, line=84

I tried to follow the examples provided on this page (I'm not using DCTCP):

https://www.nsnam.org/docs/models/html/tcp.html

I also see that CoDel has attributes "UseEcn",: https://www.nsnam.org/doxygen/classns3_1_1_co_del_queue_disc.html,

[Tom Henderson]

On 6/16/20 12:15 PM, Md Ashiqur Rahman wrote:
> I am on ns3 version 3.30 and trying to manually enable/disable the ECN.
> I have tried different ways to do so, but always end up with error.
> Please suggest how I can set enable/disable ECN properly (of course
> default is disabled).

ECN is not supported in that model in release 3.30. It will be in
release 3.31, about to be published; it was recently added.

Please have a look at ns-3-dev code.

- Tom

[Md Ashiqur Rahman]

Hi Tom,

Thanks for the reply. I think I figured it out and looks to me that it's working properly on 3.30. Here's the modification I made:

1. Update the codel-queue-disc header and cc files with the latest one.

2. Use the following to enable the ECN:

Config::SetDefault ("ns3::CoDelQueueDisc::UseEcn", BooleanValue (true));

Config::SetDefault ("ns3::TcpSocketBase::EcnMode", StringValue ("ClassicEcn"));

Best-

Ashiq

[Tom Henderson]

On 6/16/20 12:59 PM, Md Ashiqur Rahman wrote:

Hi Tom,

Thanks for the reply. I think I figured it out and looks to me that it's working properly on 3.30. Here's the modification I made:

1. Update the codel-queue-disc header and cc files with the latest one.

2. Use the following to enable the ECN:

Config::SetDefault ("ns3::CoDelQueueDisc::UseEcn", BooleanValue (true));
Config::SetDefault ("ns3::TcpSocketBase::EcnMode", StringValue ("ClassicEcn"));

Best-

Ashiq

Yes, in general, there are changes to how ECN is configured between ns-3.30 and ns-3.31.  If you are doing research using ECN, I recommend to upgrade once the release is published.  ns-3.31 will include ECN support in FqCoDel and CoDel.

- Tom

[Md Ashiqur Rahman]

Hi Tom,

Thanks for your suggestion. I’ll definitely keep that in mind.

Best-

Ashiq