User Manual
Default Priority:
Default Priority is used for untagged packets hold QoS priority. It provide 8 priorities (0~7) in each port. When untagged packets enter one port of the switch, they will have the precedence you set default priority in that port. For instance, as you choose port 2 with default priority 2 and the untagged frames get into the port 2 of the switch, they will possess priority 2 QoS precedence. Then priority 2 packets must check the setting of QoS function. In default, the priority 2 is in Queue 1. Finally, the packets will obey the Scheduling Method, Weighted Round Robin or Strict Priority, to reach QoS effect. Nevertheless, you want Default Priority to act on, please enable
VIP Port:
VIP Port is particularly used for the “Strict Priority” method of QoS Setting Scheduling. Please note that you should apply “Strict Priority” Scheduling Method before the usage of VIP Port.
The function of VIP Port is to offer the highest priority of QoS to the port you set up. As to the other ports with disabled VIP Port whose priority cannot be higher than those with enabled VIP Port. For example, if port 2, 3 and 4(Port 2’s VIP Port is enabled) transmit untagged packets to port 1 at the speed of 100MB and result in the traffic congestion, then the packets that port 1 had received will be only from port 2. Due to the priorities of packets coming from port 3, 4 are lower than the ones of VIP port - port 2, so the packets will form port 3, 4 will be dropped. Furthermore, this VIP Port capability also cooperates with 802.1p QoS similarly.
Publication date: July, 2006
Revision A2
35
