A wireless access point should be thought of as a 2-port switch (switches with just 2 or 3 interfaces used to be called a “bridge”, so some may refer to it as a 2-port bridge instead of switch).
One port on the WAP is the Ethernet port that connects to the wired part of the network. This Ethernet port should report all of the standard utilization and error counters, but this depends on the WAP manufacturer’s support of SNMP standards.
The second port on the WAP would be the radio transmitter “port”. It should also show transmit and receive utilization as well as errors seen on the interface (just like an Ethernet port). This information is also dependent on the WAP manufacturers’ adherence to SNMP standards if the information is available.
If the above information is available on both ports, then it is easy to validate that the Ethernet port is healthy or unhealthy, as well as the amount of packet loss seen on the radio transmitter port.
All WiFi radio transmitters will see a certain amount of packet loss depending on how many WiFi SSIDs exist, how many users exist in the area, and other environmental obstructions may exist near the AP.
If you are monitoring a number of APs in your environment, it may be valuable to note the loss seen on the radio transmitter port for each AP in the environment. You may determine that the average loss is from 2% to 5%.
If you notice that one AP has a higher average loss, or some really strange spikes in loss at certain times of the day, it may mean that you should investigate the environment where the AP resides. If the AP in question is located on a wall that is shared with an elevator shaft, or is located near some high voltage power sources, it may be best to re-locate the AP away from these RFI sources.
Note: The same is true for Microwave and satellite links, but the devices must support standard SNMP values and error counters.