Hi Ita,

You want to know the bandwith usage of your CX ports? Does those ports are connected into a switches? If yes, you can use any switch performance tool or even SNMP query the port stats or portperfshow on brocade, etc..

Don't know if I answer the question

Sebastien

or you could use Navisphere analyser to monitor each port and look at total bandwidth option

i have the brocades fabric switches. do u know if there any built in tool i can use?

do you know where i can find this tool? or maybe i already have it installed with my navi manager?

You can also look in the Brocade switch itself.
In my switches this option is called the "Performance Monitor".