These dashboard charts represent four categories of statistics relevant to all the wireless radio interfaces of your wireless network (e.g. AP 320s and AP 208s both have two radio interfaces, a 5GHz radio and a 2.4 GHz radio, while an AP 201 has a single 2.4GHz radio). The charts are designed to give you a real-time snap shot of the utilization and health of your wireless network and also to identify any service areas with notable packet loss or channel noise. These four charts indicate the following across all radio interfaces on your network: 1) range of throughput, 2) which radios/APs are servicing the most wireless stations, 3) how much 802.11 packet loss is occurring and 4) how much noise is detected by the radios/APs in your wireless network.
The key to understanding the data in these charts is to use your mouse on a chart as follows. To interpret one if the 10 sections of a graph, hover your mouse over the bar of interest. This will show you the data range for that bar and the number of radio interfaces that fall within in that data range. Right-click on that same bar and select Show Details to see individual data points used to plot the graph. From this list of radios click Open in the Diagnostics column to see the same four statistical charts for just that individual radio. These charts automatically refresh every minute
Tips on interpreting the graphs appear when you click Graph Help, such as descriptions for each chart and a numeric version of the chart information. To redefine the amount of data displayed on a chart, Click Advanced, provide a new minimum and maximum value and then click Redraw.
This chart represents the distribution of each individual wireless radio’s throughput over the range of the radio with the lowest throughput and the radio with the highest throughput. Throughput is defined as the sum of the transmitted and received bits-per-second for that radio measured over the last two minutes.
This chart shows the distribution of wireless stations across the radios in your network. The leftmost bars represent radios supporting the fewest wireless stations and the right-most bars represent radios supporting the most wireless stations.
Retry % is the percentage of the total packets sent by the radio to the specified station with the 802.11 retry bit set. This metric provides insight on how often the radio needs to retransmit 802.11 packets to the specified station before an 802.11 ACK is received from that station.
This chart represents the distribution of packet loss across all wireless radios on this controller over the last two minutes. A packet is counted as lost when the configured number of transmissions/retries has been exhausted for that packet and no 802.11 ACK was received. Like the Throughput chart, each bar represents a range of loss and how many radios fall within that range. The network is performing best when most radios are in the leftmost columns. The colors in the chart are a clue to the relative health of the traffic, darkest green being the best result (low loss). Radio Ambient Channel Noise Chart
Noise is defined as either random noise with no coherence or coherent noise introduced by the devices mechanism or processing. Noise level is calculated in each wireless radio and represents the noise floor. No averaging method is used here and the noise level and noise floor are the same. The noise floor is represented in dbm which is a negative value.
Channel utilization is the achieved percentage of throughput related to the net bit rate in bit/s of a digital communication channel. For example, if the throughput is 70 Mbit/s in a 100 Mbit/s Ethernet connection, the channel utilization is 70%.
The Management Overhead Distribution dashboard chart tracks the percentage of bandwidth used for beacons and probes and other non-data transmissions.