Tuesday, August 2, 2011

Cisco Live Sessions

Cisco allowed virtual sessions free this year, and they are recorded so I am finally getting around to watching a few. I strongly recommend browsing the selection.


Some highlights from the QoS Design clinic I'm watching now.

Uncompressed HD video - 1.5 Gbps
compressed to - 3-5 Mbps (300:1)
Which is why a single packet dropped in 10,000 is visible to watchers.

This makes it 100 times more sensitive than voice and requires sub-millisecond jitter.


Suggests not just marking packets but also policing.

Eg. No voice endpoint will ever send more than 128kps of data, so if traffic is coming in a trusted voice port and getting tagged with your Voice QoS designation, either drop or re-classify it when it exceeds the 128kps threshold.

-Priority Queue should be less than 33% of link but best effort guaranteed 25%

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