There is a configuration setting in Radio, Basic, called Multicast data rate, with the options of highest basic, lowest basic, and highest supported. The 2.4GHz radio defaults to Highest Basic, and the 5GHz radio defaults to Lowest Basic.
This parameter is not discussed it the User Guide.
Can anyone speak to the decision process for selecting this parameter?
@jscascio wrote:
There is a configuration setting in Radio, Basic, called Multicast data rate, with the options of highest basic, lowest basic, and highest supported. The 2.4GHz radio defaults to Highest Basic, and the 5GHz radio defaults to Lowest Basic.
This parameter is not discussed it the User Guide.
Can anyone speak to the decision process for selecting this parameter?
This parameter defines the data rate at which all multicast and broadcast packets are forwarded by the access point. Higher data rates give better throughput (more packets transmitted within a fixed time), while lower data rates give better range/reliability.
The data-rate used for unicast packets is dependent on the clients capability and current state of the connection (on a per packet basis moving up/down based on what data-rate is working best for a particular client); for multicast/broadcast a single rate is used for all packets sent from the radio (since there is no ACK there is no feedback for the AP to adjust its rate).
For general applications the range/reliability is the preferred option (hence 5GHz defaulting to 6Mbps); on 2.4GHz (with 11b clients) the lowest basic rate of 1Mbps would use up a lot of airtime hence we default to 11Mbps which is a good balance for most client types. Unless you are running multicast video streams or some application that shares data with multiple client devices using broadcast/multicast addresses, the defaults should be ok.
Note that you can also configure the general data rates of the radio (currently in the CLI, will be added to GUI in a future release), and for very high density deployments removing the lower data rates altogether (Eg: 1,2,5.5Mbps from 2.4GHz) is helpful (would yield better average airtime utilization, clients would roam to another AP sooner instead of sticking to an AP at very low data rates and a good signal).
We will add this to the UserGuide, thanks for pointing that out.
Hi.
There is a limit in multicast traffic?. We are trying to transmit 8 Mbps UDP Multicast IPTV and we obtain Continuity Errors.
There is a mode in wich we can priorize multicast traffic?
Regards