l
Source MAC address
l
Destination MAC address
l
Protocol type field encapsulated in Layer 2 packets
l
Layer 3 protocol type
l
ACL
l
Discarded packets
Priority Mapping
Different packets carry different precedence fields. For example, VLAN packets carry the 802.1p
field, and IP packets carry the DSCP field or IP precedence. The mappings between priority
fields must be configured on gateways to retain priorities of packets when the packets traverse
different networks.
To ensure QoS for different packets, the S3700 maps packet priorities or the default 802.1p
priority of an interface to local priorities. The S3700 then determines the queues that packets
enter based on the mappings between internal priorities and queues. It then performs traffic
shaping, congestion avoidance, and queue scheduling. In addition, the S3700 can re-mark
priorities of outgoing packets so that the downstream device can provide differentiated QoS
based on packet priorities.
shows the mappings between internal priorities and queues.
Table 1-1
Mappings between internal priorities and queues
Internal Priority
Queue Index
BE
0
AF1
1
AF2
2
AF3
3
AF4
4
EF
5
CS6
6
CS7
7
NOTE
A color is used to determine whether the packets are discarded, and is independent of the mappings between
internal priorities and queues.
Traffic Behavior
Complex traffic classification is required to provide differentiated services. Complex traffic
classification takes effect only when it is associated with a traffic control action or a resource
allocation action.
S3700HI Ethernet Switches
Configuration Guide - QoS
1 Class-based QoS Configuration
Issue 01 (2012-03-15)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
3