Cisco interface - GB of transfer software

[dale.turner at mountaincable.on.ca (Dale Turner)]

Good morning all,

I hope my post isn't too off topic but I was wondering if anyone is 
using some open source or purchased software that would give me the 
monthly Data transfer from cisco switch ports so I can monitor/bill 
against some hosting customers. I know we can create our own but looking 
to see if there was something that anyone is using and recommends.

Thank you very much

Dale Turner