Huawei Quidway S5600 Series User Manual

Operation Manual - QoS&QoS Profile
Quidway S5600 Series Ethernet Switches Chapter 1 QoS Configuration
Huawei Technologies Proprietary
1-9
Packets sent via this
interface
high priority
Low priority
Classify
Packets sent
Sending queueDequeue
queue 7
queue 6
queue 5
queue 4
queue 3
queue 2
queue 1
queue 0
Packets sent via this
interface
high priority
Low priority
Classify
Packets sent
Sending queueDequeue
queue 7
Packets sent via this
interface
high priority
Low priority
Classify
Packets sent
Sending queueDequeue
queue 7
queue 6
queue 5
queue 4
queue 3
queue 2
queue 1
queue 0
Figure 1-5 Diagram for SP queues
SP queue-scheduling algorithm is specially designed for critical service applications.
An important feature of critical services is that they demand preferential service in
congestion in order to reduce the response delay. Assume that there are 8 output
queues on the port and the preferential queue classifies the 8 output queues on the port
into 8 classes, which are queue7, queue6, queue5, queue4, queue3, queue2, queue1,
and queue0. Their priorities decrease in order.
In the queue scheduling, SP sends packets in the queue with higher priority strictly
following the priority order from high to low. When the queue with higher priority is
empty, packets in the queue with lower priority are sent. You can put critical service
packets into the queues with higher priority and put non-critical service (such as e-mail)
packets into the queues with lower priority. In this case, critical service packets are sent
preferentially and non-critical service packets are sent when critical service groups are
not sent.
The disadvantage of SP queue is that: if there are packets in the queues with higher
priority for a long time in congestion, the packets in the queues with lower priority will be
“starved to death” because they are not served.
2) WRR queuing

Huawei Quidway S5600 Series Specifications

General

Brand	Huawei
Model	Quidway S5600 Series
Category	Switch
Language	English