What to watch
Your port is shared by peering, private circuits and cloud connections. Monitoring it well helps you plan capacity and catch problems early.
Utilisation
Look at inbound and outbound separately. Access networks usually receive far more than they send.
Per-service view
Monitor each VLAN to see how much traffic goes to peering, to each cloud and to each partner.
Errors
CRC errors, input errors and optical power levels point to physical problems. Rising errors usually precede a failure.
The 95th percentile
Capacity planning commonly uses the 95th percentile of five-minute samples, which ignores brief spikes while reflecting sustained peaks.
Trends
Plot monthly peak utilisation. When the trend shows you will reach 70–80% within a few months, start the upgrade process.
Peer1IX provides traffic graphs for every port and service.
