Nortel Networks 2300 manual QoS on an AP, WMM in a Nortel Network

Wi-Fi Multimedia 307

QoS on an AP

AP access ports use forwarding queues to prioritize traffic to wireless clients. When the AP receives a packet from an WSS switch, the AP places the packet into one of four forwarding queues. The AP’s queue selection is based on the IP ToS setting in the tunnel header of the encapsulated data packet received from the WSS. The AP has the following forwarding queues, listed from lowest priority to highest priority:

•Background

•Best effort

•Video

•Voice

Figure 15 shows an example of WMM providing high priority forwarding for voice traffic through the network.

Figure 15. WMM in a Nortel Network

Layer 3

3 802.1p = 7 IP ToS = 0xe0 Voice Data. . .

WSS Switch A

802.1p = 7 IP ToS = 0xe0 Voice Data. . .

WSS Switch

4

2

1

Layer 3
Tnl Hdr IP ToS = 0xe0 Voice Data. . .
AP A	AP B
Srvc Type = 7 Voice Data . . .

Tnl Hdr IP ToS = 0xe0

Voice Data. . .

5

6

Voice

Video

Best Effort

Bgrnd

This figure shows the following process:

1A user sends voice traffic from a WMM VoIP phone. The phone marks the QoS field of the packet with service type 7, indicating that the packet is for high priority (voice) traffic.

2AP A receives the voice packet, encapsulates the data in an IP tunnel packet, and maps the service type to the equivalent IP ToS value in the tunnel header. Then the AP sends the packet to the WSS switch.

Nortel WLAN Security Switch 2300 Series Configuration Guide