Wireless QOS.

I am getting close to finishing my ONT studies, i am just reading over some more wireless QOS. I have to admit that the only form of wireless i use is while i am surfing the web at home. Wireless is something that does not interest me, or it is something i would not pursue with futher studies on the subject. I prefer cables what more can i say!!
To maintain QOS you use DSCP (Differentiated Services Code Point) for packet marking. This is because there is layer two marking (COS) carried in the 802.1p header. This information would be lost over trunk links, unless restored by a capable device. Traffic destined to a AP does not have 802.1p QOS tag information, because the AP don’t connect to a switch port using a trunk. Packets sent by the wireless network will not have layer 2 QOS markings. It is thus important to be able to use layer 3 DSCP information for QOS.
With QoS, bandwidth can be managed more capably across LANs, which includes WLAN’s and WANs. This is how QoS provides enhanced and consistent network services:

•Supports dedicated bandwidth for critical users and applications
•Controls jitter and latency (required by real-time traffic)
•Manages and minimizes network congestion
•Shapes network traffic to smoothen the traffic flow
•Sets network traffic priorities

Cisco Unified Wireless Products support WMM, a QoS system based on the IEEE 802.11e draft that has been published by the Wi-Fi Alliance.

The controller supports four QoS levels, list are the WMM category and the 802.11e priority:

•Platinum/Voice—Ensures a high quality of service for voice over wireless. 6 or 7 802.11e priority
•Gold/Video—Supports high-quality video applications. 4 or 5 802.11e priority
•Silver/Best Effort—Supports normal bandwidth for clients. This is the default setting. 0 or 3 802.11e priority
•Bronze/Background—Provides the lowest bandwidth for guest services. 1 or 2 802.11e priority

In a nutshell VoIP clients should be set to Platinum, Gold, or Silver while low-bandwidth clients can be set to Bronze.



~ by bigevil on November 20, 2009.

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