What is bandwidth utilization and how is it calculated

[villerblender87]

Hi everyone,

When we have below Tx and Rx load on the router, how is port utilization calculated? Can I calculate utilization by combining Tx and Rx percentiles.

Please note that we have a 2Gbps P2P link. Based on a 2 Gbps link, here is an example.

For example, Tx=185/255 equals 72.54% of the total bandwidth.

In this case, Rx=66/255=25.88% of the total bandwidth.

The total bandwidth will be 97% if we combine both.

What impact does it have on performance. I would like to know how to calculate this.

Thank you.

[balaji.bandi]

there is good discussion for reference :

https://community.cisco.com/t5/routing/how-to-calculate-bandwidth-use-at-the-point-in-time/m-p/4096211#M335225

[Joseph W. Doherty]

You need to divide your result by 2 for overall link utilization, although with duplex links we're usually very interested in load for TX and RX, individually.

As to "What impact does it have on performance.", none, to some, to much, to lots.  Average link utilization can often not reflect its impact to performance.  I've seen cases where 1% is bad and 100% is okay.  Much depends on the "nature" and service needs of the traffic using the link.  (I've also often seen many cases where network engineers see utilization under 50% and cannot understand why users keep complaining the network is slow.)