Juniper JUNOSE 11.1.X - QUALITY OF SERVICE CONFIGURATION GUIDE 3-21-2010, Configuration Manual

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Chapter 21
Configuring QoS for 802.3ad Link
Aggregation Groups
This chapter provides information for configuring QoS for 802.3ad link aggregation
groups.
QoS topics are discussed in the following sections:
■
QoS for 802.3ad Link Aggregation Interfaces Overview on page 183
■
Hashed Load Balancing for 802.3ad Link Aggregation Groups
Overview on page 186
■
Subscriber Load Balancing for 802.3ad Link Aggregation Groups
Overview on page 186
■
Guidelines for Configuring QoS over 802.3ad Link Aggregation Groups on page 190
■
Configuring the Scheduler Hierarchy for Hashed Load Balancing in 802.3ad Link
Aggregation Groups on page 191
■
Enabling Default Subscriber Load Balancing for 802.3ad Link Aggregation
Groups on page 191
■
Configuring the Scheduler Hierarchy for Subscriber Load Balancing in 802.3ad
Link Aggregation Groups on page 192
■
Configuring Load Rebalancing for 802.3ad Link Aggregation Groups on page 193
■
Monitoring QoS Configurations for 802.3ad Link Aggregation Groups on page 195
QoS for 802.3ad Link Aggregation Interfaces Overview
You can configure QoS for 802.3ad link aggregation interfaces. To ensure that QoS
is applied properly to the interface column, you configure the QoS profile using either
a hashed loadbalancing scheme or a subscriber loadbalancing scheme.
Types of Load Balancing
For hashed load balancing, you configure the scheduler hierarchy with Ethernet
queues, and the system replicates them on each link within the link aggregation
group (LAG). The system demultiplexes each packet to one of the active links in the
LAG using a random hash generated by fields in the packet header. For example,
when an IP packet is routed to a LAG, the hash algorithm is based on the IP Source
Address and Destination Address in the IP header.
QoS for 802.3ad Link Aggregation Interfaces Overview
■ 183