[e2e] Are Packet Trains / Packet Bursts a Problem in TCP?

[Jeroen Massar]

Bob Braden wrote:
>   *> 
>   *> There are places where improving TCP burstiness can be of value, such  
>   *> as in the cases where (usually Linux) TCPs decide to send their  
>   *> entire next window in a short period of time it would be nice of they  
>   *> could be convinced to do so at a rate that doesn't exceed cwnd/srtt. 
> 
> The ability of an OS to do that pacing has traditionally been limited
> by the coarse-grain software clocks that were available -- i.e., by
> interrupt overhead.  Suppose CPU chip designers listened to the needs
> of networking people.  Could they provide fine-grain hardware clocks
> that could be easily used by transport protocols for pacing out packets
> in large windows?

You mean like HPET ?
http://www.intel.com/hardwaredesign/hpetspec.htm

Also partially discussed here:
http://newkerneltrap.osuosl.org/node/6750

These should give one quite a good clock for doing things like that.

Greets,
 Jeroen


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