Data Center switching oversubscription

[p.caforio]

Dear All,

I manage a data center that consist in 4 stacked 3750x and 3 HP c-Class Enclosures with 2 Cisco 3020 switches each.

On each 3020 switch I currently have 2 links (aggregated) to the 3750x stack.

Since we are going to fill one of the Enclosures with 16 blade I was concerting on the uplink bandwith to the 3750 stack.

Is there any tool or best practice to calculare the minimal oversubscription ratio to avoid drops?

I saw the 20:1 rule for access layer but I believe that it is used for switches where end-devices are connected (PC, printers , etc..) , not for Data Center.

thanks,

Paolo

[richbarb · Accepted solution]

Hi Paolo,

There is no such thing, you can have a oversubscription of 100:1, if you wish. What tells you if this oversubscription is good or not is the application behavior, how are you using your network.

There are a lot of tools in the market (some are free) that helps you monitoring your consumption of network bandwidth, take this data with the growth forecast of the network to get a number.

I'll not listing the networking monitoring tools, because that are hundreds out there.

Regards.

Richard