User's Manual

that time, each mesh node evaluates alternative links if the existing uplink falls below the configured
threshold level (the link becomes a sub-threshold link). It is recommended to use this default startup-
subthreshold value.
l subthreshold-only: connected mesh nodes evaluate alternative links only if the existing uplink becomes a
sub-threshold link.
If a mesh point using the startup-subthreshold or subthreshold-only mode reselects a more distant parent
because its original, closer parent falls below the acceptable threshold, then as long as that mesh point is
connected to that more distant parent, it seeks to reselect a parent at the earlier, shorter distance (or less) with
good link quality. For example, if a mesh point disconnects from a mesh parent 2 hops away and subsequently
reconnects to a mesh parent 3 hops away, then the mesh point continues to seek a connection to a mesh
parent with both an acceptable link quality and a distance of two hops or less, even if the more distant parent
also has an acceptable link quality.
For information about the procecure to configure mesh radio profiles, see Creating and Editing Mesh Radio
Profiles on page 551.
RF Management (802.11a and 802.11g) Profiles
The two 802.11a and 802.11g RF management profiles for an AP configure its 802.11a (5 Ghz) and 802.11b/g
(2.4 GHz) radio settings. Use these profile settings to determine the channel, beacon period, transmit power,
and ARM profile for a mesh AP’s 5 GHz and 2.5 Ghz frequency bands. You can either use the “default” version
of each profile, or create a new 802.11a or 802.11g profile which you can then configure as necessary. Each RF
management profile also has a radio-enable parameter that allows you to enable or disable the AP’s ability to
simultaneously carry WLAN client traffic and mesh-backhaul traffic on that radio. This value is enabled by
default. For information about configuring RF Management Radio profiles, see 802.11a and 802.11g RF
Management Profiles on page 509.
If you do not want the mesh radios carrying mesh-backhaul traffic to support client traffic, consider using a dedicated
802.11a/80211/g radio profile with the mesh radio disabled. In this scenario, the radio carries mesh backhaul traffic
but does not support client Virtual APs.
Mesh nodes operating in different cluster profiles can share the same radio profile. Conversely, mesh portals
using the same cluster profile can be assigned different RF Management Radio profiles to achieve frequency
separation (for more information, see “Deployments with Multiple Mesh Cluster Profiles”).
Adaptive Radio Management Profiles
Each 802.11a and 802.11g radio profile references an Adaptive Radio Management (ARM) profile. When you
assign an active ARM profile to a mesh radio, ARM's automatic power-assignment and channel-assignment
features automatically select the radio channel with the least amount of interference for each mesh portal,
maximizing end user performance. In earlier versions of this software, an AP with a mesh radio received its
beacon period, transmission power, and 11a/11g portal channel settings from its mesh radio profile. Mesh-
access AP portals now inherit these radio settings from their dot11a or dot11g radio profiles.
Each ARM-enabled mesh portal monitors defined thresholds for interference, noise, errors, rogue APs and
radar settings, then calculates interference and coverage values and selects the best channel for its radio band
(s). The mesh portal communicates its channel selection to its mesh points via Channel Switch Announcements
(CSAs), and the mesh points change their channel to match their mesh portal. Although channel settings can
still be defined for a mesh point via that mesh point's 802.11a and 802.11g radio profiles, these settings are
overridden by any channel changes from the mesh portal. A mesh point takes the same channel setting as its
mesh portal, regardless of its associated clients. If you want to manually assign channels to mesh portals or
Dell Networking W-Series ArubaOS 6.4.x | User Guide Secure Enterprise Mesh | 539