# Wired Intelligent Edge (Campus Switching and Routing)

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Occasional Contributor II

## switch fabric speed vs. routing/switching capacity

Hi,

after reading through the Datasheet of the Aruba 5406 the following question came up... what is meant by switch fabric speed vs. routing/switching capacity and where is the difference?
If someone could help me to better understand that in detail, I`d be really grateful!

Accepted Solutions
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MVP

## Re: switch fabric speed vs. routing/switching capacity

Hi Daniel.

If you see, maximun port capacity por Aruba 5406R is reached with 12 40GE ports. In that situation, your routing/switching capacity is: 12x40Gbps = 480 Gbps, and considering in/out direction (full duplex) you get the 960 Gbps of the datasheet. So your switch needs a minimun switching capacity of 960 Gbps to work at wire-speed. It seems that switch fabric speed is the internal swithing structure of the switch (not available to public, only to Aruba HPE personnel) that is used to serve that minimun switching capacity.

You need 960 Gbps (that depends on the physical port configuration of your switch) considering the mentioned port configuration, and the switch has 1015 Gbps to serve that demand (switch fabric speed). If we suposse there is no other routing/switching demand, the switch has 55 Gbps to serve a higher demand.

Regards

PS: If you feel this information is useful and solved your question or problem, please do not forget to mark it as a solution and give me some kudos.

All Replies
Highlighted
MVP

## Re: switch fabric speed vs. routing/switching capacity

Hi Daniel.

If you see, maximun port capacity por Aruba 5406R is reached with 12 40GE ports. In that situation, your routing/switching capacity is: 12x40Gbps = 480 Gbps, and considering in/out direction (full duplex) you get the 960 Gbps of the datasheet. So your switch needs a minimun switching capacity of 960 Gbps to work at wire-speed. It seems that switch fabric speed is the internal swithing structure of the switch (not available to public, only to Aruba HPE personnel) that is used to serve that minimun switching capacity.

You need 960 Gbps (that depends on the physical port configuration of your switch) considering the mentioned port configuration, and the switch has 1015 Gbps to serve that demand (switch fabric speed). If we suposse there is no other routing/switching demand, the switch has 55 Gbps to serve a higher demand.

Regards

PS: If you feel this information is useful and solved your question or problem, please do not forget to mark it as a solution and give me some kudos.
Highlighted
MVP Guru

## Re: switch fabric speed vs. routing/switching capacity

Hi! I think the 55 Gbps delta between calculated switching speeds (960 Gbps versus 1015 Gbps) would be directly related to the Packet Size used to perform the speed test: 64 Bytes long versus > 64 Bytes long.