link utilization

[sarahr202]

hi every body!

I just want to know if following is correct method to find link utilization:

considering only transmission link i.e tx

link speed= 100 Mb

Number of bit traveling down the transmission line at certain time T1=10Mb

utilization= 10/100= 0.01 or 10 percent

so link utilization is 10 percent at T1

thanks a lot!

[satish_zanjurne · Accepted solution]

1.It is correct..!!!!

2.Also you can use loading of the interface in "show interface " command.

3.Also see the input rate & output rate in "show interface " command

HTH..rate if helpful...

[glen.grant · Accepted solution]

If you look at the show interface command cisco uses the metrics of a percentage of 255 for the link. If it says 65/255 then it is running approx. 25% of the link capacity.

[Joseph W. Doherty · Accepted solution]

You can't send 10 Mbps down a 100 Mbps link (running at 100 Mbps). Bits are logically modulated at 100 Mbps. What happens is 90% of the time 10 Mbps isn't transmitted. However, physical link utilization would be 10%.

To further confuse, link utilization is often measured by bits contained within packets or frames. A link could be running at 100% physical utilization, but packet or frame bit counting would likely show less than 100%. For instance, on Ethernet, due to frame preambles and interframe gaps, you can't possibly transfer at 100%.