25-8 User Guide for the Avaya P580 and P882 Multiservice Switches, v6.1
Chapter 25
■ Setting a Physical Port to Ignore Tag Priority
■ Setting the Priority of a MAC Address
■ Displaying the Priority of a MAC Address
■ Setting a Physical Port to Use DiffServ
■ Setting a Physical Port to Mask DiffServ Bits
■ Assigning a Priority to a DSCP
■ Displaying the DiffServ Table
■ Displaying the QoS Settings for a Physical Port
■ Setting Up an ACL Rule
■ Setting Up a Default ACL Rule
■ Displaying ACL Rules
Default Priority
By default, the switch uses the priority from the 802.1p tag field, if present,
to classify a frame.
If you do not change any of the QoS default settings and the frame does not
have an 802.1 tag or Cisco ISL tag, the switch assigns the priority of the
physical port to the packet. Each physical port has a default priority of 3.
For information on how to change the priority for a physical port, see
“Setting the Priority of a Physical Port” later in this chapter.
However, the priority of the 802.1 tag and Cisco ISL tag take precedence
over the priority of the physical port, so the switch uses the priority of the
physical port only if:
■ No tags are present in the frame
or
■ You have set the physical port to ignore priorities in tags.
For information on how to set a port to ignore priorities in tags, see
“Setting a Physical Port to Ignore Tag Priority” later in this chapter.
* Note: 802.1p packets that are received with a tag priority of 0 on a 50-
series layer 2 (non-routing) module, and that must be routed via
the FORE path on an 80-series supervisor, are queued and
transmitted with a priority of 4. This priority change is due to
the conversion from the high-low priority system that 50-series
modules use to the 8-level priority system that 80-series
modules use.
