PeakHour lets you monitor the throughput of any device that supports the SNMP or UPnP protocol. Typically devices such as Internet routers, wireless access points, servers, switches, network attached storage (NAS) support monitoring by one or both of these protocols.
If your Internet router is UPnP enabled and shows up in PeakHour with a green status icon and "Reporting Bandwidth" then you should be able to use PeakHour to monitor your Internet throughput.
Be sure to perform a 'sanity check' of what PeakHour is reporting vs. what you expect to see. Some router manufacturers are a little lazy when it comes to ensuring they report throughput accurately, so it makes sense to double-check. If you suspect PeakHour is under or over-reporting usage, try the steps in this FAQ to determine if the data is accurate: PeakHour isn't seeing my router / isn't reporting bandwidth / appears to be reporting incorrectly. How can I check?
SNMP is a more capable monitoring protocol than UPnP as it allows you to specify which interface's throughput you'd like to monitor. This allows you more control and provides better visibility of what is going on on your router. Most routers support monitoring of the WAN or Internet interface and may also support monitoring of the WiFi interface (if supported) and ethernet ports (either as a group or individual).
All routers however are different so it's not possible to provide a simple guide on which interface to use. If you're unsure, try generating some traffic of a known speed (speedtest.net is excellent for this) and comparing it to what you see in PeakHour.
These types of devices are relatively easy to monitor as they either support SNMP or can have SNMP enabled.
Check out our guide: I'd like to monitor my Mac/PC/Linux devices. How can I enable them? for more information.
"Appliance"-like devices that don't support running SNMP or UPnP can't generally be monitored as there is no way to query them.
However, you can monitor their usage indirectly by monitoring the Internet router they are connected to and you can monitor other devices in order to build up an overall picture of usage on your network.