Re: Network starvation question

On 11/4/23 03:37, Yuri wrote:
> Router is also involved, and the provider's network as well.
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> But I think that there is a bug in the FreeBSD's network code that it allows a slower TCP connection to be hammered like this, unless there is a good explanation for this observation.
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> Yuri
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> 


As you mention router and provider network are involved my first thought is bufferbloat. See https://en.wikipedia.org/wiki/Bufferbloat

As UDP is involved FreeBSD doesn't do any flow control on that traffic and just sends as much as the application requests it to do. This is not a bug in FreeBSD. The design of the application is to requests FreeBSD to do this by using UDP instead of TCP.

A solution to this would be to limit bandwidth of application A (mentioned in your original mail) to leave just enough space for application B to perform well. Maybe the application has support for this. Otherwise a mechanism like "dummynet" (in combination with ipfw firewall) can do this.


Regards,
Ronald.