Term
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Definition
| Introduced as part of EDCA, there are four Access Categories: Voice, Video, Best Effort, and Background. |
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Term
| Application Visibility and Control (AVC) |
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Definition
| A method used on the wireless controller to inspect the payload of the traffic. Once it identifies the type of application in use, it has the ability to change the DSCP markings, rate limit, or drop the traffic. |
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Term
| Arbitrated Interframe Space Number (AIFSN) |
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Definition
| A mandatory wait timer that must be observed by stations before transmitting onto the medium. There are different ones for each Access Category. |
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Term
| Carrier Sense Multiple Access / Collision Avoidance (CSMA/CA) |
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Definition
| A “listen before you talk” method of transmitting a frame onto the wireless medium. |
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Term
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Definition
| The phenomenon that occurs when multiple stations must compete for access to a wireless medium. In Wi-Fi, only one station may transmit at a given time. If more than one station wishes to transmit, it creates contention for the medium. |
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Term
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Definition
| A period that a station must wait before transmitting a frame. |
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Term
| Diffserv Code Point (DSCP) |
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Definition
| An IP marking scheme that uses 6 bits in the IP packet header. |
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Term
| Distributed Coordination Function (DCF) |
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Definition
| The rules of how a frame is transmitted onto the wireless medium. |
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Term
| Enhanced Distributed Channel Access (EDCA) |
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Definition
| An improvement over DCF that was introduced as part of 802.11e and provides QoS handling through different media access rules for each class of service. |
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Term
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Definition
| An AutoQoS macro that is supported on both AireOS and IOS-XE controllers as a way to implement a wide array of QoS features in best-practice approach. |
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Term
| Transmission Opportunity (TXOP) |
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Definition
| A time period given for a station to continually transmit frames once it has won the EDCA contention algorithm. |
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Term
| Transmission Specification (TSpec) |
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Definition
| A method of Call Admission Control that is used in 802.11e to reserve bandwidth on an AP, allowing a client to transmit high-priority traffic. |
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Term
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Definition
| A 3-bit field in the 802.11 frame header that identifies the QoS class of the frame. This field allows for eight levels of service, although there are only four available Access Categories. |
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Term
| Wireless Multimedia (WMM) |
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Definition
| The QoS compatibility standard used by the Wi-Fi Alliance (WFA). It leverages the recommendations in the 802.11e specification. |
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