Re: 10GE TOR port buffers (was Re: 10G switch recommendaton)

Saku Ytti wrote:

No, you're not crazy. If your core is higher rate than your customer, then you need at minimum serialization delay difference of buffering. If core is 10G and access 100M, you need buffer for minimum of 100 packets, to handle the single 10G incoming, without any extra buffering.

The required amount of memory is merely 150KB.

Now if you add QoS on top of this, you probably need 100 per each class you are going to support.

If you have 10 classes, it is still 1.5MB.

And if switch does support QoS but operator configures only BE, and operator does not limit BE queue size, operator will see buffer bloat,

1.5MB @ 10Gbps is only 1.2ms, which is not buffer bloat. Masataka Ohta