Changing Linux MPTCP kernel configuration during simulation

[Michaël]

Hello,

I'm using NS-3 DCE with the Linux MPTCP kernel to do some tests. I'm wondering if it is possible to change a parameter like the scheduler during the simulation? The scheduler is set in advance through a sysctl variable.

I tried using Simulator::Schedule to change the MPTCP scheduler from default to roundrobin (setting another value for the sysctl variable), but eventhough the parameter seems to change in the stack, the existing connection keeps using the old scheduler. I'm assuming it will only apply to new connections that are made after that point.

Is there any way to achieve this? I'd rather not change any of the Linux kernel code itself. 

Thanks in advance,

Michaël

[Hajime Tazaki]

At Thu, 14 May 2015 10:18:04 -0700 (PDT),

Hello Michael,

I guess this is a specific case to the Linux mptcp kernel,
it would be nice to ask their mailing list, not on the ns-3
or DCE community.

-- Hajime

[Matt Anonyme]

The behavior you describe is correct. You will have to modify the kernel to do that. The scheduler saves scheduler-specific per-connection data in a (void*) structure so you may need to erase the current data and replace with a new one.
Look at net/mptcp/rr_scheduler.c for instance