Session Explorer
The session explorer is used to navigate through each session and go into the detail.
The session explorer is used to navigate through each session and go into the detail.
Navigating through the sessions is as easy as selecting a session in the Session List, or sliding through the Session Cards. The Timeline Slider shows a yellow overlay over the timeline corresponding to the currently selected session.
This area lists the sessions in chronological order (first session captured at the top). It provides an 'at-a-glance' approach to understanding where a poor session might be experienced.
The colored signal column quickly informs how well a particular session met the design criteria for received signal strength. It shows how well the signals have met the secondary RSSI threshold (the lower of the two).
The format is: % Signals < Secondary RSSI (Minimum recorded RSSI for the Session)
Sessions with a significant number of RSSI measurements below the secondary RSSI threshold could be considered to be part of a concern where the device is unable to find an AP with suitable signal strength.
The coloring is calculated as follows
Green: < 10% measurements below secondary RSSI
Amber: 10 – 20% measurements below secondary RSSI
Red: > 20% measurements below secondary RSSI
There are 4 indicators to allow easy identification of issues.
Beacons Lost. This will have a check mark in it if this session reported beacons lost. When this shows it is a good indication that the device has gone out of range of the connected AP and did not manage to roam in time
Short Session. This indicates that the session length was less than the session threshold configured in settings. Sometimes this is fine, but in many case it can indicate instability. In the worst scenarios you will see a lot of bouncing between APs when this flag happens
Medium Busy. This indicates that a session was determined to be busy according to the thresholds you configured in settings. This network is working hard but it is coping - quite normal for high density environments such as stadia
Medium Congested. This indicates the medium is utilised more than your upper threshold (e.g., 80%) and it would be expected to have very poor performance. A lot of sessions like this are likey to indicate an unusable environment.
An example of what you might see in a congested environment
The session flow is where the main roaming analysis takes place.The objective is to determine if roaming
Happens at the right time and is quick
Is effective in finding the next AP
Is triggered for the right reasons.
The session flow is made up of a card per session. Each card provide the following
Details of the connected network equipment (AP, Cell Tower) and the environment
The signals specific to this session
A roaming table
How much of the session was spent attempting to roam
A chronological list of the roaming events to understand the decisions the device logic went through to arrive at the final outcome
Roaming analysis uncovers a lot of information which is not available anywhere else.
The internal device logic cannot be seen anywhere except the device. This is not usually reported to the controller (however there are some recent vendor announcements indicating that this may change for some vendor-client relationships)
What is interesting is looking at why roams happen.
Most roam attempts will have the reason "Low RSSI" which is where the internal signal strength triggers start the roaming process.
You can observe AP initiated roams for band steering and load balancing. These are BTM - BSS Transition Management which allow an AP to request a station to transition to a specific AP, or suggest a set of preferred APs, due to network load balancing or termination of the connection with the current AP. This helps the station identify the best AP from the list of candidates sent. The AP does not always follow the request though!
Look out for the different roam reasons when you do your testing
The additional detail gives 3 areas of additional information for each session
A histogram of RSSI for the session. Useful to quickly identify if the session was dragging on weak signal
A list of APs the device was specifically looking for in the scan (not always made available in the log)
The reasons for all roam attmepts within this session.
