Cisco Unified Wireless Network (CUWN) introduced a new feature, VideoStream, for enterprise wide deployments. This feature enables the wireless architecture to deploy
multicast video streaming across the enterprise to wireless clients. This feature recompenses the drawbacks that degrade the video delivery as the streams and clients scale
in an enterprise network. VideoStream makes video multicast to wireless clients more reliable and using the bandwidth/spectrum more efficiently. In a multi-streaming
enterprise network, the feature assigns priority to the stream and provides more weight age to preferred streams. This feature also guarantees delivery of video to wireless
clients and denies video to new client subscription under heavy channel utilization.

Requirements

Knowledge of Cisco Unified Wireless LAN Solution.

Components Used

VideoStream feature is available in Cisco Unified Wireless Network software version 7.0with enhancements in Cisco Unified Wireless Network software version 7.2. This
feature is supported on all wireless LAN controllers (WLANs) and newer generation indoor access points (APs). This feature is not available on autonomous access points
and outdoor access points.

Related Products

Supported Wireless Hardware and Software

VideoStream is supported on all wireless LAN controllers. This includes the Cisco 5500 Controller, Cisco 4400 Controller, Cisco 2100 Controller and WiSMs. VideoStream is
also supported on the Cisco 2504 standalone and Cisco WiSM-2 Controller. IGMPv2 is the supported version on all of the controllers.

VideoStream is supported on all access points. This includes all 802.11n models of access points consisting of Cisco Aironet 3600 series access point, Cisco Aironet 3500
series access point, Cisco Aironet 1260 series access point, Cisco Aironet 1250 series access points, Cisco Aironet Cisco Aironet 1140 series access points and Cisco
Aironet 1040 series access points. VideoStream is also supported on Cisco Aironet 1240AG* series access points and Cisco Aironet 1130AG* series access points.

The VideoStream feature was introduced in the CUWN 7.0 version of controller code and supported on later versions of controller software with enhancements.

Conventions

Refer to

Cisco Technical Tips Conventions

for more information on document conventions.

Theory of Operation

Before going into details about the VideoStream feature, some of the shortfalls in Wi-Fi multicast need to be understood. 802.11n is a prominently discussed wireless
technology for indoor wireless deployments. Equally prominent requirement is seen in multimedia service on an enterprise wireless network, in particular, video. Multicast
video streaming will be a cost effective solution in a huge enterprise network as unicast of video services will not scale in an enterprise wide streaming. Multicast does not
provide any MAC layer recovery on multicast/broadcast frames. Multicast and broadcast packets do not have an Acknowledgement (ACK), and all packet delivery is best
effort. Multicast over wireless with 802.11a/b/g/n does not provide any mechanism for reliable transmission.

Enterprise wireless deployments are prone to interference, high channel utilization, incompatible client, low SNR at the edge of the cell. Video delivery to wireless clients is at
the highest mandatory data rates on the respective channel. There are also many clients sharing the same channel but have different channel conditions, power limitations
and client processing capabilities. Therefore, multicast will not be a reliable transmission protocol to all the clients in the same channel as each client has different channel
conditions as seen below in the diagram.

Wireless multicast does not prioritize the video traffic even though it is Differentiated Service Code Point (DSCP) marked by the video server. The application will see a loss of
packets with no ACK, and retries to the delivery will be bad. In order to provide reliable transmissions of multicast packet, it is necessary that the network classifies queues

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