Technical data

802.11n Video Service Module (ViSM)

Rate Limiting : off

Capture frames sent by other APs in the network : on

MC3K-1#

For a detailed explanation of the packet capture profile commands, see the Trouble-

shooting chapter of the Meru System Director Configuration Guide.

802.11n Video Service Module (ViSM)

Video streaming has the low latency and loss requirements of voice with the

high-throughput requirements of data. The Meru Networks Video Service Module™ (ViSM)

is an optional licensed software module that delivers predictable 802.11 video perfor-

mance with minimal delay, latency and jitter. Sustainable high data rates, even in mixed

traffic, are supported along with synchronization of video and audio transmissions.

ViSM also introduces additional mechanisms for optimizing unicast and multicast video

such as application aware scheduling, voice/video synchronization, and client-specific

multicast group management. Features include the following:

 High throughput with low burstiness offers predictable performance and

consistent user experience

 Application-aware prioritization synchronizes the voice and video components of

a video stream, adapting the delivery of each frame based on its importance to

the application.

 Multicast group management optimizes delivery to only those Virtual Ports whose

clients are members of the multicast group.

 Seamless video-optimized handoff proactively reroutes the multicast delivery

tree to prevent lost video frames during a transition between access points and

ensures zero loss for mobile video.

 User and role based policy enforcement provides granular control over application

behavior.

 Visualization reveals which clients are running which applications.

Implementing ViSM

Virtual Port already changes multicast to unicast transmissions. ViSM adds per-client IGMP

Snooping to the transmission. Therefore, to implement ViSM, turn on IGMP Snooping. CLI

commands control IGMP snooping (see Meru System Director Command Reference). At this

time, ViSM licensing is not enforced.