Nortel Networks 450 manual Port Transmit Queue

Using the BayStack 450 10/100/1000 Series Switch

Port 5

		Traffic	High priority
		class
	7		packet
	6	High
	5
	4
User priority	Port
	transmit
(6)
	queue
	3
	2	Low
	1
	0
			BS45025A

Figure 1-35. Port Transmit Queue

As shown in Figure 1-35, the switch provides two transmission queues, High and Low, for any given port. Frames are assigned to one of these queues on the basis of user_priority using a traffic class table. This table is managed by using the Traffic Class Configuration screen (Figure 1-36). The table indicates the corresponding traffic class that is assigned to the frame, for each possible user_priority value. If the frame leaves the switch formatted as a tagged packet, the traffic class assigned to the frame is carried forward to the next 802.1p capable switch. This allows the packet to carry the assigned traffic class priority through the network until it reaches its destination.

The following steps show how to use the Traffic Class Configuration screen to configure the port priority level shown in Figure 1-34.

For more information about using the Traffic Class Configuration screen, see “VLAN Configuration” on page 3-24.

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