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Flex 7500 Wireless Branch Controller Deployment Guide
Client ACL Support
Stream Admission
As mentioned earlier, while video is an efficient, high-impact means of communication, it is also very
bandwidth intensive, and as is seen, not all video content is prioritized the same. From earlier discussion
it is clear that organizations investing in video cannot afford to have network bandwidth consumed
without any prioritization of business-critical media.
Multicast to Unicast
By enabling 802.11n data rates and providing packet error correction, multicast-to-unicast capabilities
of Cisco VideoStream enhances reliability of delivering streaming video over Wi-Fi beyond best-effort
features of traditional wireless networks.
A wireless client application subscribes to an IP multicast stream by sending an IGMP join message.
With reliable multicast, this request is snooped by the infrastructure, which collects data from the IGMP
messages. The AP checks the stream subscription and configuration. A response is sent to the wireless
client attached to the AP in order to initiate reliable multicast once the stream arrives. When the multicast
packet arrives, the AP replicates the multicast frame and converts it to 802.11 unicast frames. Finally, a
reliable multicast service delivers the video stream as unicast directly to the client.
Higher Video Scaling on Clients
With Cisco VideoStream technology, all of the replication is done at the edge (on the AP), thus utilizing
the overall network efficiently. At any point in time, there is only the configured media stream traversing
the network, because the video stream is converted to unicast at the APs based on the IGMP requests
initiated by the clients. Some other vendor implementations do a similar conversion of multicast to
unicast, but do it inefficiently as evidenced by the load put on the wired network to support the stream.
Switch Configuration
VideoStream can be deployed on an existing branch wide wired and wireless network. The overall
implementation and maintenance costs of a video over wireless network are greatly reduced. The
assumption is that the wired network is multicast enabled. In order to verify that the access switch is part
of the layer 3 network, connect a client machine to the switchport and verify if the client machine is able
to join a multicast feed.
Show run | include multicast
displays if multicast is enabled on the layer 3 switch else if not enabled
for multicast, you can enable multicast by executing the following command on the switch:
L3_Switch#
show run | include multicast
ip multicast-routing distributed
