Sunday, May 16, 2010

Wi-Fi Tip: Multicast Reliability

Multicast data is sent at the highest enabled basic-rate (Mandatory
rate). This can cause issues for clients at the edge of the cell who
are connected at a lower enabled rate and cannot properly de-modulate
the frame. To improve reliability, set only the lowest enabled data
rate as basic/mandatory to ensure that clients at the cell edge can
receive multicast frames.


  1. Actually early wireless multicast deployments were tricky because a lot of folks didn't know how cisco worked multicast. When there was issues we would case our tail on the wired side. When in fact a capture showed the mutlti cast on the lowest man rate.

    A solid deisgn should allow for the lower data rates to be disabled.

    Good post

  2. Yes, in conjunction with voice deployments either 11Mbps or 12Mbps is usually recommended as the lowest enabled data rate depending on whether 802.11b clients need to be supported.