How Access Points are Defined by AirShield

In general an AccessPoint is considered to be a single device that provides 802.11 networking to a room, open area, closet, etc. These may be connected via Ethernet to an edge or core switch or act as 802.11 repeaters, relaying network traffic from one area to another. A typical AccessPoint with external antennas looks like this:

Each antenna supports one or more radios transmitting on approved frequencies, also known as channels, within the 2.4 GHz, 5GHz or 6GHz bands.

A Service Set Identifier (SSID) is a unique name given to a network. An AccessPoint radio may advertise multiple SSIDs (up to 32 in some cases). The internal radio advertising the SSID uses an IEEE-approved MAC Address, known as the Basic Service Set Identifier (BSSID). A group of BSSIDs advertising an ESSID make up the accessible network for clients to connect.

Users, for the most part, are unaware of the BSSID they are connected to and may roam from BSSID to BSSID as signal quality and load demands it.

Access Points in The Console

When viewing the list of Access Points on the Console you will notice a large number of BSSIDs with the same network name (ESSID). These are the unique radio addresses as seen by the AirShield. Around every 2 minutes the AirShield will report to the Console the details of its observed AccessPoints, Clients, Sessions and other decoded radio objects.

IMPORTANT: A BSSID may not be visible from some vendor console or management systems. In most cases a calculation is made based on the radio MAC address for each advertised network to generate the BSSID. Reversing this address to find the actual AccessPoint is different for each vendor.

• https://help.ubnt.com/hc/en-us/articles/115002536648-UniFi-BSSID-to-MAC-Mapping
• https://documentation.meraki.com/MR/WiFi_Basics_and_Best_Practices/Calculating_Cisco_Meraki_BSSID_MAC_Addresses
• https://github.com/meraki/bssid-calculator
• http://www.my80211.com/home/2011/5/2/wlc-how-cisco-virtualizes-the-base-radio-mac-address-on-the.html
• https://community.arubanetworks.com/t5/Controller-Based-WLANs/How-is-the-BSSID-derived-from-the-Access-Point-ethernet-MAC/ta-p/176290

Multiple AirShields, Multiple Observations

In cases where multiple AirShields are nearby, each may observe the same Access Point. In this case the Access Point list will show the details from the last reported AirShield. The details from each AirShield will be available from the History view on the AP Details page: