How to assess the need to increase the speed of the Internet?

Question

Computer networks

Greetings!
I administer the BC network. The boss asks: "Is the Internet speed enough?" It is clear that the more the better. There is zabbix monitoring on the gateway, I collect traffic statistics. What criterion to choose to determine the degree of congestion of the channel and the need for its expansion? Are there any best practices on this topic?

Answer 1

Channel load percentage by time. That is, the channel was loaded by 60% within 4 hours out of 8 hours, by 90% within 1 hour out of 8, by 30% within 3 hours.
Thus, if the channel is loaded more than 80% more than half the time (6 hours out of 8), then it is necessary to expand by 50%.