Release Notes

661 | rf arm-profile Dell Networking W-Series ArubaOS 6.4.x| Reference Guide
controller receives a client steer request from an AP, the controller identifies the optimal APcandidate and
manages the client’s relocation to the desired radio. This is an improvement from previous releases, where the
ARMfeature was managed exclusively by APs, the without the larger perspective of the client's
RFneighborhood.
The following client/AP mismatch conditions are managed by the client match feature:
l Load Balancing: Client match balances clients across APs on different channels, based upon the client load
on the APs and the SNR levels the client detects from an underutilized AP. If an APradio can support
additional clients, the AP will participate in client match load balancing and clients can be directed to that AP
radio, subject to predefined SNRthresholds.
l Sticky Clients: The client match feature also helps mobile clients that tend to stay associated to an AP
despite low signal levels. APs using client match continually monitor the client's RSSI as it roams between
APs, and move the client to an AP when a better radio match can be found. This prevents mobile clients
from remaining associated to an APs with less than ideal RSSI, which can cause poor connectivity and reduce
performance for other clients associated with that AP.
l Band Steering/Band Balancing: APs using the client match feature monitor the RSSI for clients that
advertise a dual-band capability. If a client is currently associated to a 2.4 GHz radio and the AP detects that
the client has a good RSSIfrom the 5 Ghz radio, the controller will attempt to steer the client to the 5 Ghz
radio, as long as the 5 Ghz RSSI is not significantly worse than the 2.4 GHz RSSI, and the APretains a
suitable distribution of clients on each of its radios.
ARM Scanning
The default ARM scanning interval is determined by the scan-interval parameter in the ARM profile. If the AP
does not have any associated clients (or if most of its clients are inactive) the ARM feature will dynamically
readjust this default scan interval, allowing the AP obtain better information about its RF neighborhood by
scanning non-home channels more frequently. Starting with ArubaOS 6.2, if an AP attempts to scan a non-
home channel but is unsuccessful, the AP will make additional attempts to rescan that channel before skipping
it and continuing on to other channels.
Using Adaptive Radio Management (ARM) in a Mesh Network
When a mesh portal operates on a mesh network, the mesh portal determines the channel used by the mesh
feature. When a mesh point locates an upstream mesh portal, it will scan the regulatory domain channels list to
determine the channel assigned to it, for a mesh point always uses the channel selected by its mesh portal.
However, if a mesh portal uses an ARM profile enabled with a single-band or multi-band channel/power
assignment and the scanning feature, the mesh portal will scan the configured channel lists and the ARM
algorithm will assign the proper channel to the mesh portal.
If you are using ARM in your network, is important to note that mesh points, unlike mesh portals, do not scan
channels. This means that once a mesh point has selected a mesh portal or an upstream mesh point, it will tune
to this channel, form the link, and will not scan again unless the mesh link gets broken. This provides good
mesh link stability, but may adversely affect system throughput in networks with mesh portals and mesh
points. When ARM assigns optimal channels to mesh portals, those portals use different channels, and once
the mesh network has formed and all the mesh points have selected a portal (or upstream mesh point), those
mesh points will not be able to detect other portals on other channels that could offer better throughput. This
type of suboptimal mesh network may form if, for example, two or three mesh points select the same mesh
portal after booting, form the mesh network, and leave a nearby mesh portal without any mesh points. Again,
this will not affect mesh functionality, but may affect total system throughput.