[Click] Load balancing - packet reordering

[Torquato Bertani]

> For Tcp have you enabled Selective Acks (SACK) ? This should help with
> excessive retransmissions due to out of order packets.

I can't control tcp end to end implementation or options in all cases,
so I prefer to work in IP layer and/or read TCP/UDP packet if useful.

> Another idea that may possibly help is to split the IP flows to two seperate
> queues, i.e. by using a hash classifier to output all even IP Address flows
> in one queue, and all odd IP Addess flows to the second queue. Each outgoing
> inteface can then pull from their respective queues, ensuring that each
> flow's packets will always end up in the same queue. Obviously this can
> affect full utilization of the load balanced link, but I'm sure there are
> better hash functions than the odd/even ip address way.

That's interesting and easy to implement but limits the load balancing
in cases of single flow. It depends of traffic type.

> On a side note, have you done any test on SMP click with your configuration?
> Theoretically these 'dual path' configurations should benefit from SMP
> Click.

Unfortunately I have a single processor hardware...

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