Cisco Cisco DX70 Design Guide
Cisco DX Series Wireless LAN Deployment Guide
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Note: The Cisco DX Series does not utilize the RF parameters in the Client Roaming section of the Cisco Unified Wireless
LAN Controller as scanning and roaming is managed independently by the phone itself.
LAN Controller as scanning and roaming is managed independently by the phone itself.
Multicast
When enabling multicast in the wireless LAN, performance and capacity must be considered.
The Cisco DX Series primarily utilizes active mode, but if there is an associated client that is in power save mode, then all
multicast packets will be queued until the DTIM period.
With multicast, there is no guarantee that the packet will be received the by the client.
The multicast traffic will be sent at the highest mandatory / basic data rate enabled on the access point, so will want to ensure
that only the lowest enabled rate is configured as the only mandatory / basic rate.
The client will send the IGMP join request to receive that multicast stream. The client will send the IGMP leave when the
session is to be ended.
The Cisco DX Series supports the IGMP query feature, which can be used to reduce the amount of multicast traffic on the
wireless LAN when not necessary.
Ensure that IGMP snooping is also enabled on all switches.
It is recommended to enable Multicast Direct in the Cisco Unified Wireless LAN Controller.
The Cisco DX Series primarily utilizes active mode, but if there is an associated client that is in power save mode, then all
multicast packets will be queued until the DTIM period.
With multicast, there is no guarantee that the packet will be received the by the client.
The multicast traffic will be sent at the highest mandatory / basic data rate enabled on the access point, so will want to ensure
that only the lowest enabled rate is configured as the only mandatory / basic rate.
The client will send the IGMP join request to receive that multicast stream. The client will send the IGMP leave when the
session is to be ended.
The Cisco DX Series supports the IGMP query feature, which can be used to reduce the amount of multicast traffic on the
wireless LAN when not necessary.
Ensure that IGMP snooping is also enabled on all switches.
It is recommended to enable Multicast Direct in the Cisco Unified Wireless LAN Controller.
Note: If using Coexistence where 802.11b/g/n and Bluetooth are being used simultaneously, then multicast voice is not
supported.
supported.
Designing the Wireless LAN
The following network design guidelines must be followed in order to accommodate for adequate coverage, call capacity and
seamless roaming for the Cisco DX Series.
seamless roaming for the Cisco DX Series.
Planning Channel Usage
Use the following guidelines to plan channel usage for these wireless environments.
5 GHz (802.11a/n)
5 GHz is the recommended frequency band to utilize for operation of the Cisco DX Series.
The Cisco DX Series supports Dynamic Frequency Selection (DFS) and Transmit Power Control (TPC) from 802.11h, which
are required when using channels operating at 5.260 - 5.700 GHz, which are 15 of the 24 possible channels.
The Cisco DX Series supports Dynamic Frequency Selection (DFS) and Transmit Power Control (TPC) from 802.11h, which
are required when using channels operating at 5.260 - 5.700 GHz, which are 15 of the 24 possible channels.
DFS dynamically instructs a transmitter to switch to another channel whenever radar signal is detected. If the access point
detects radar, the radio on the access point goes on hold for at least 60 seconds while the access point passively scans for
another usable channel.
TPC allows the client and access point to exchange information, so that the client can dynamically adjust the transmit power.
The client uses only enough energy to maintain association to the access point at a given data rate. As a result, the client
contributes less to adjacent cell interference, which allows for more densely deployed, high-performance wireless LANs.
5 GHz channels overlap their adjacent channel, so there should be at least 1 channel of separation for adjacent access points.
Need to ensure there is at least 20 percent overlap with adjacent channels when deploying the Cisco DX Series in the 802.11a/n
environment, which allows for seamless roaming. For critical areas, it is recommended to increase the overlap (30% or more)
to ensure that there can be at least 2 access points available with a signal of-67 dBm or higher, while the Cisco DX Series also
meets the access point’s receiver sensitivity (required signal level for the current data rate).
detects radar, the radio on the access point goes on hold for at least 60 seconds while the access point passively scans for
another usable channel.
TPC allows the client and access point to exchange information, so that the client can dynamically adjust the transmit power.
The client uses only enough energy to maintain association to the access point at a given data rate. As a result, the client
contributes less to adjacent cell interference, which allows for more densely deployed, high-performance wireless LANs.
5 GHz channels overlap their adjacent channel, so there should be at least 1 channel of separation for adjacent access points.
Need to ensure there is at least 20 percent overlap with adjacent channels when deploying the Cisco DX Series in the 802.11a/n
environment, which allows for seamless roaming. For critical areas, it is recommended to increase the overlap (30% or more)
to ensure that there can be at least 2 access points available with a signal of-67 dBm or higher, while the Cisco DX Series also
meets the access point’s receiver sensitivity (required signal level for the current data rate).