[Babel-users] RTT stability inside a GRE tunnel

[Denis Ovsienko]

>  This is what I would *suspect*:
>
>  Coming out of the GRE tunnel, your packet would have to be decapsulated by
>  the kernel, and then re-queued into the network bottom half.  Generally,
>  the kernel does interrupt mitigation, and since this is a soft-interrupt,
>  that queue is serviced from a clock interrupt.
>
>  As such, you'd see the values quantized to the clock interrupt, which is
>  exactly what I see in your diagram.

Hi.

That's a worthwhile hypothesis (and not excluding ICMP software-forwarded elsewhere), but shouldn't the green (ICMP in GRE) RTT be strictly greater than the red (plain ICMP) RTT in this case?

-- 
    Denis Ovsienko