Queue Scheduling - HP 830 Series Configuration Manual

Table 145 Description on 802.1p priority
802.1p priority (decimal)
0
1
2
3
4
5
6
7

Queue scheduling

In general, congestion management uses queuing technology. The system uses a queuing algorithm for
traffic classification, and then uses a precedence algorithm to send the traffic. Each queuing algorithm
handles a particular network traffic problem and has significant impacts on bandwidth resource
assignment, delay, and jitter.
In this section, two common hardware queue scheduling algorithms are introduced: Strict Priority (SP)
queuing and Weighted Round Robin (WRR) queuing.
SP queuing
SP queuing is designed for mission-critical applications that require preferential service to reduce
response delay when congestion occurs.
Figure 481 SP queuing
A typical switch provides eight queues per port. As shown in
queues on a port into eight classes, numbered 7 to 0 in descending priority order.
SP queuing schedules the eight queues according to the descending order of priority. It sends packets in
the queue with the highest priority first. When the queue with the highest priority is empty, it sends
802.1p priority (binary)
000
001
010
011
100
101
110
111
472
Description
best-effort
background
spare
excellent-effort
controlled-load
video
voice
network-management
Figure 481, SP queuing classifies eight