- Identifying the priority, also called class, of the frame or packet. The switch can identify the priority of the frame or packet by using one or more of the following criteria:
- The priority of the physical port that the switch received the frame or packet on
- Cisco ISL tag priority
- 802.1p tag priority (default)
- The source or destination MAC address
- The DiffServ code point
- The IP protocol (assigned by means of an ACL rule)
- The source or destination IP address (assigned by means of an ACL rule)
- The source or destination TCP or UDP port (assigned by means of an ACL rule)
For more information on identifying the priority of traffic, see "Classification of Traffic" later in this chapter.
- Storing the frame or packet in one of eight ingress queues.
The switch stores the frame or packet in the queue that matches the priority that was identified in Step 1.
- Forwarding the frame or packet from the ingress queue to its destination.
If you enable policing for the queue, the switch forwards ingress traffic that falls within the maximum bit rate that you set and drops ingress traffic that exceeds the maximum bit rate. For more information on policing, see "Ingress Policing" later in this chapter.
