Manual:Multicast and wireless
Anything over L2 networking layer is ignored by 802.11, nstream or NV2. These only provide meads of physical and data link layers. As such only data that is taken into account that can be somehow altered by user is Data link layer With data frames being passed over the physical level.
There are differences how radio links work with unciast and multicast frames. This is where also direction comes into play, weather sender is access-point (AP) or wireless station (STA) and also, receiving end therefore is important. Practical difference is that when multicast packet is sent over wireless it does not have ack, nor retry, as the result only mechanism available to ensure higher probability for packets to reach its destination is to send them over in lowest data rate (in this case - it means higher transmit power, on the other end of link - there is difference between receive sensitivity on certain rates.
Here are listed how radio treats certain packets:
- L2 unicast AP->STA - radio unicast
- L2 multicast AP->STA - radio multicast
- L2 unicast STA->AP - radio unicast
- L2 multicast STA->AP - radio unicast
- L2 unicast WDS - radio unicast
- L2 multicast WDS - radio unicast