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QoS PowerPoint Presentation

QoS

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QoS

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Presentation Transcript

  1. QoS

  2. Solution Features • Supports WMM • Support U-APSD • Supports TSPEC Admission Control • Supports 7920 Admission Control • Provides Voice Instrumentation

  3. Applications Background Best Effort Video Voice Internal Collision Resolution Classification • WMM Access separates traffic types in to 4 categories • Background, Best Effort, Video, Voice • These all compete for the channel with different delay and random back off characteristics

  4. IEEE 802.11e—EDCAEnhanced Distributed Channel Access • Superset of DCF • EDCA allows high priority traffic first access to the media, by altering the IFS, and the random back-off • Transmission Operation (TXOP) is given to the lowest QoS Station (QSTA) • QSTAs with the same Access Category (AC) have the same back-off time A[0] IFS Contention Window (CWmin[0]) Time (t) A[n] IFS Contention Window (CWmin[n]) Time (t)

  5. IEEE 802.11e WMM Access Categories

  6. U-APSD • AKA WMM-Power Save • Client receives buffered frames when it transmits, rather than polling for buffered frames • Increased Power Saving • Increased Call capacity

  7. TSPEC Based Call Admission Control • Allows clients to request capacity for calls on the AP • Allows the APs to reserve capacity for establishing calls and accepting roaming calls

  8. WMM Performance Features

  9. QoS Mapping Table • WMM CoS is are mapped to AVVID DSCP marking by a translation table • AVVID DSCP markings are mapped to WMM CoS using the same table

  10. 3 2 1 4 LWAPP QoS 802.1p DSCP LWAPP Encapsulated 802.1p DSCP Payload • Ensures that packets receive the proper QoS handling from end to end • Policing of 802.11e UP / 802.1p and IP DSCP values ensures that wireless endpoints conform to network QoS policies 802.11e DSCP Payload DSCP Payload LWAPP Tunnels WLC Ethernet Switch AP DSCP LWAPP Encapsulated 802.1p DSCP Payload DSCP Payload 802.11e DSCP Payload

  11. Q & A