Actual bandwidth is just what it says it is. It is the Actual amount of bandwidth you use per month and it is measured in GB.
When you are talking in terms of mb/s, it is a form of measurement that is based on the 95th percentile. This means that your bandwidth is measured as follows.
1.) First Day of the month, 12:01am the first MRTG reading is polled on the switch and stored in a database.
2.) Every 5 minutes thereafter the switch is polled to get another reading which is stored in the database.
3.) By the last day of the month, approximately 8,000 - 9,000 readings have been stored in the database.
4.) The entire month's readings are sorted from highest to lowest.
5.) The top 5% of these readings are discarded.
6.) The amount that remains is the 95th percentile reading that is recorded for monthly bandwidth usage.
Originally posted by Shane When you are talking in terms of mb/s, it is a form of measurement that is based on the 95th percentile.
Just a quick correction on that... the 95th percentile is just one way of many to measure bandwidth in mbps (mega bits per second). Some providers measure it based on the peak line rate achieved, some give you a fixed rate connection (ie; physically limited to 5 mbps), some use a monthly average, some use [arbitrary percentage] percentile.
Originally posted by Reference so If I'm allocated 1mbps, and if measured with the 95th percentile rule, my average transfer every 5 mins cannot be more then 1mbps? Is it somethng like that?
"Allocated" and "limited to" are different, it depends on your provider's setup. A lot of the cheaper colo companies just throw your server on a layer 2 switch and set your port to 10 mbps or something like that, so they don't really have any granular control over how many bandwidth you can actually use.
Originally posted by Reference so it's better using a switch than a router?
Uh, switches and routers do different things, I don't think you quite understood my point.
I like connecting each customer to their own port on a true layer 3 device, with their own subnet and granular control over traffic shaping, rate-limiting, IP filtering, etc. This makes things a lot more secure and ultimately you have a lot of flexibility in dealing with issues as they come up.
Obviously, this isn't cheap to do however. Layer 3 ports cost a whole lot more than layer 2 ports do.