[Cake] overhead and mpu

Dennis Fedtke dennisfedtke at gmail.com
Tue Sep 5 02:00:04 EDT 2017

Hi Ryan,

Thanks for you answers.
Lets assume again ethernet over docsis connection at 50 Mbit/s.
So to get 50 Mbit/s ethernet perfomance, the docsis link speed needs to be set at a higher link speed to compensate for the 18 header ethernet overhead, or?
The docsis link syncs at exactly 50Mbit/s. When cake is set to exactly 50Mbit/s, it is actually set at a higher speed then the link actually is.

For mpu why 64?
I assume minimum 46bytes ethernet payload + 18bytes header?

But why does cake use hard_header_len for the header size which is 14 bytes?

I don't know how packet sheduler system works, but maybe it is not needed to include the ethernet header.

cake does work on ip pakets or? so this is layer3 i think.
the hole thing with ethernet headers is happening in layer2.
This would change the minimum packet size to 46 or?


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