Reference Guide

Table Of Contents
Flow Tracker and Pipeline Manager
The Flow Tracker is a sub-component of the core controller that facilitates management of flow
rules, meters and groups across all datapaths managed by the controller. Its functionality is
accessed through the ControllerService API.
The Pipeline Manager is a sub-component that maintains an in-memory model of the flow table
capabilities of (1.3) datapaths. When an application attempts to install a flow, the flow tracker will
consult the pipeline manager to choose a suitable table in which to install the flow, if no explicit
table ID has been provided by the caller.
Flow Management
Flow management includes:
Getting flow statistics from a specified datapath, for one or all flow tables
Adding or modifying flows on a specified datapath
Deleting flows from a specified datapath
See the earlier Message Library section for an example of how to create a FLOW_MOD message.
Group Management
Group management includes:
Getting group descriptions from a datapath, for one or all groups.
Getting groups statistics from a datapath, for one or all groups.
Sending group configuration to a datapath.
Note that groups are only supported for OpenFlow 1.3 datapaths.
Meter Management
Meter management includes:
Getting meter configurations from a datapath, for one or all meters
Getting meter statistics from a datapath, for one or all meters.
Sending meter configuration to a datapath
Note that meters are only supported for OpenFlow 1.3 datapaths. However, some 1.0 datapaths
can support metering through the use of EXPERIMENTER messages.
Flow Rules
The primary mechanism used in the implementation of SDN applications is the installation of flow
rules (aka “FlowMods”) on datapaths (aka switches).
Flow Classes
Before a FlowMod can be constructed and sent via the controller service, a corresponding “Flow
Class” must be registered. The flow class explicitly defines the match fields that will be present in the
flow, and the types of actions that will be taken when the flow rule is matched. The registration of
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