HauteSpot FAQs

WMM works by dividing traffic into 4 access categories: background, best effort, video, voice. QoS policy (different handling of access categories) is applied on transmitted packets, therefore it is transmitting device is treating different packets differently - that is - e.g. AP does not have control over how clients are transmitting packets, and clients do not have control over how AP transmits packets.

AP and client classifies packets based on priority assigned to them, according to table (as per WMM spec): 1,2 - background 0,3 - best effort 4,5 - video 6,7 - voice

To be able to use multiple WMM access categories, not just best effort where all packets with default priority 0 go, priority must be set for those packets. By default all packets (incoming and locally generated) inside router have priority 0.

"Better" access category for packet does not necessarily mean that it will be sent over the air before all other packets with "worse" access category. WMM works by executing DCF method for medium access with different settings for each access category (EDCF), which basically means that "better" access category has higher probability of getting access to medium - WMM enabled station can be considered to be 4 stations, one per access category, and the ones with "better" access category use settings that make them more likely to get chance to transmit (by using shorter backoff timeouts) when all are contending for medium. Details can be studied in 802.11e and WMM specification