Nokia ESB26 User Manual page 222

18.
When the switch detects ingress traffic that contains 802.1p prioritization information, the
traffic is mapped to various hardware queues on the egress port of the switch. The
transmitting hardware queue determines the bandwidth management and priority
characteristics used when transmitting packets.
The default mapping of each 802.1p priority value to QoS priority is shown in table 18-2. To
change the default configuration use the command qos map command in Global
Configuration mode.
By default, 802.1p priority information is not replaced or manipulated, and the information
observed on ingress is preserved when the packet is transmitted. This behavior is not affected
by the switching or routing configuration of the switch. However, the switch is capable of
inserting and/or overwriting 802.1p priority information when it transmits an 802.1Q tagged
frame. The 802.1p priority information that is transmitted is determined by the hardware
queue that is used when transmitting the packet. To replace 802.1p priority information, use
the qos remark command in Global Configuration mode.
NOTE The switch does not change the VLAN Priority Tag (VPT) for a switched packet that comes
with an 802.1Q tag, since it assumes that the sender of the packet has already determined
the VPT.
Packets received without a tag have their VPT set in by the command qos remark.
MAC-Based Traffic Groupings
QoS priority values can be assigned to packets destined for a specific MAC address.
The MAC address options, defined below, are as follows:
•
For static and secured MAC addresses, this can be done by using the qos mac
command in Global Configuration mode. This command creates a static MAC
address with the specified priority.
•
For dynamic MAC addresses, the MAC address inherits the priority from the port on
which it was learned.
The priority on the port is configured by the qos priority command in Interface Configuration
mode.
MN700004 Rev 01
Quality of Service
Figure 18-1 802.1p Priority Header Fields
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