Core/Distribution/Access Oversubscription Ratio Calculation

[Learnercisco]

Hi Tech Guys, 

Could you share some guide about calaculation Oversubscription ratio between Access to Distribution and Distribution to Core,

For example for Cisco 9400 per slot capacity is 80Gbps and and how can we use 24 Port 10G Moudule which is giving full capacity= 24x10= 240Gbps. how can we calculate oversubscription ratio. 

Thanks in Advance.  

[Mark Malone]

hi
if its sup1 and the its maxed to 80 GB per slot and you have the full 24 ports running at 10GB then its a 3/1ratio of over subscription , 240/80

looks like only the 9404 running sup 1X or XY can do 240GB per slot

EDIT: corrected mine back to front , early mornings :)

[Seb Rupik]

Hi there,

The linecard oversubscription would be 240/80 which gives a ration of 3:1 .

The calculate the combined oversubscription through the layers, you multiply the ratios. eg:

Say you have an access ratio of 3:1 and an aggregation of 1.5:1  that would give 3*1.5 = 4.5:1

cheers,

Seb.

[Learnercisco]

Thanks Seb for reply,

So could u elaborate  if we have 

From Access(48X1G) Uplink 2x10G to distrubtion Switch &

disrtribution to Core uplink = 2x10G 

Access to Distrbution Oversubscription ratio:?

Distribution to Core oversubscription ratio:?

Thanks

[Seb Rupik]

The access layer will be 2.4:1 , but we need to know the linecard configuration for the aggregation switch, to work out the combined oversubscription.

cheers,

Seb.