The ESS profiles are configured with the RF Virtualization Mode as native cell or virtual cell. This configuration is applied to all access points supporting the particular ESS profile. This document focuses on configuring the virtual and native cell. These configurations are supported in both tunnel and bridge modes. This diagram depicts a typical tunnel mode deployment.
Before You Begin
Verify that the access points are discovered by the Controller and are operational in the Enabled – Online state. Navigate to Configuration > Devices > APs.
Configuring a Virtual Cell ESS
After the access points are configured and operational, create a virtual cell ESS profile for your wireless network.
Navigate to Configuration > Wireless > ESS; click Add and populate the configuration page as per your network requirements. The following configurations are mandatory:
- ESS Profile – Name of the ESS for internal identification.
- SSID – Network name to be advertised wirelessly for the clients to see and connect to.
- RF Virtualization Mode – Set to Virtual Cell.
Fortinet recommends disabling Multicast-to-Unicast-Conversion option.
The default values can be retained for all other configurations on this page.
What is the ESS-AP Table
The ESS-AP table displays the logical mappings of the ESS on the AP interface. A single AP may have multiple radios and each radio interface may support multiple ESSIDs (wireless networks). The ESS-AP table displays the ESSIDs deployed on each individual radio.
Verifying the Virtual Cell ESS-AP Table
In a virtual cell, multiple access points combine to form a single cell. Hence, the BSSIDs for an ESSID, from multiple access points, would be the same; so all those access points appear combined as a single access point to wireless clients. To verify the ESS-AP table, navigate to Configuration > Wireless > ESS > Edit > ESS-AP Table.
- If two or more radio interfaces carries the same BSSID, then a virtual cell has been formed.
- In this example, AP-9 interface #1 and AP-11 interface #1 have independent radios yet they carry the same BSSID by forming a virtual cell.
The logical view of the ESS-AP table in the virtual cell mode is illustrated below.
Configuring a Native Cell ESS
To configure a native cell repeat the settings in section Configuring a Virtual Cell ESS and modify the RF Virtualization Mode to Native Cell; all access points will now advertise a unique BSSID.
In the Native Cell mode all the access points configured with an ESS are switched to the traditional 1, 6, and 11 multi-channel architecture.
Fortinet recommends enabling 802.11k and 802.11r to optimize AP assisted roaming.
Verifying the Native Cell ESS-AP Table
In a native cell, a radio broadcasts each of its deployed ESSIDs with its own BSSID; this is to distinguish it from the same ESSIDs in other access points. When each radio interface for all APs configured for the ESS service has a unique BSSID, then a native cell has been formed. To verify the ESS-AP table, navigate to Configuration > Wireless > ESS > Edit > ESS-AP Table
In this example each AP interface has a unique BSSID.
The logical view of the ESS-AP table in the native cell mode is illustrated below.
When the ESS is configured in the native cell mode, aligned with the multi-channel architecture, it is recommended that you enable ARRP for ease of deployment. When ARRP is enabled the APs automatically adjust the channel and power level. Navigate to Configuration > Wireless > ARRP.
Note: Ensure that Replan is deployed for the changes to take effect.
To verify that ARRP is successfully deployed, navigate to Configuration > Wireless > ARRP > AP-Radio Interfaces. Channels 1, 6, and 11 should be deployed with ARRP.
Native Cell vs Native Cell with ARRP
Fortinet recommends configuring ARRP when forming a native cell for accurate deployment.
- When the native cell is formed without ARRP, deployment in the multi-channel architecture – channels 1, 6, and 11 may NOT be accurate.
- When the native cell is formed with ARRP enabled, deployment in the multi-channel architecture – channels 1, 6, and 11 is accurate, as depicted in the example below.