Specifications

BPG_11n_v1.0 | Page 12
There are a couple of general guidelines to follow when determining the number of channel
layers needed to accommodate the type and number of clients expected.
The recommendation is to design for 32 clients per radio. The following table provides
recommendations for maximum clients per interference region for given beacon data rates.
Beacon Data Rate
Interference Region Capacity
24 Mbps (g)
200
11 Mbps (b)
100
If you determine that extra channel layers are required it is recommended that the slower
clients use a channel dedicated for them. This will allow faster clients to take full advantage
of the other channel/s.
This document will go into detail of channel layering in the section to follow.
When to use WLAN Virtualization
Virtualization requires a uniform AP model with the exception of the AP300 and AP300i.
Virtualization will work across these AP models.
As a rule the recommendation is to use WLAN virtualization.
As of this writing, there is one exception to this rule and that is if Polycom SVP (Spectralink
Voice Protocol) is used. The reason for this is the SVP has its own way of doing CAC (call
admission control) where the SVP server keeps track of the number of calls per BSS. With
Meru Networks WLAN virtualization the BSS (or parent BSS in the case of Vport) is common
to all APs (for a given channel and ESS). With WLAN virtualization SVP CAC is effectively
disabled. For this reason SVP and WLAN virtualization are not well suited for one another.
It should be noted that the newer Polycom phones and firmware now come with support for
SIP. These phones when configured to use SIP work very well in a virtualized WLAN.
Virtual Cell Boundaries (Virtual Cell Domains)
A virtual cell boundary is where one virtualized BSS ends and another begins. The simplest
type of virtualized WLAN deployment is one large Virtual Cell across the network. In this case
there are no Vcell boundaries. If the network is large enough to require multiple controllers or
if the network has multiple AP types (e.g., AP200s and AP300s) within the same building for a
given network there will be Vcell boundaries.
MERU BEST PRACTICES GUIDE | 11n Design, Implementation and Optimization