IPQoS Configuration File

This section contains full details about the parts of the IPQoS configuration file. The IPQoS boot-time activated policy is stored in the file /etc/inet/ipqosinit.conf. Although you can edit this file, the best practice for a new IPQoS system is to create a configuration file with a different name. Tasks for applying and debugging an IPQoS configuration are in Chapter 3, Creating the IPQoS Configuration File (Tasks).

The syntax of the IPQoS configuration file is shown in Example 6-3.

The example uses the following conventions:

• computer-style type – Syntactical information that is provided to explain the parts of the configuration file. You do not type any text that appears in computer-style type.

• bold type – Literal text that you must type in the IPQoS configuration file. For example, you must always begin the IPQoS configuration file with fmt_version.

• italic type – Variable text that you replace with descriptive information about your configuration. For example, you must always replace action-name or module-name with information that pertains to your configuration.

Example 6-3 Syntax of the IPQoS Configuration File

file_format_version ::= fmt_version version

action_clause ::= action {
     name action-name
     module module-name
     params-clause |  ""
     cf-clauses
}
action_name ::= string
module_name ::= ipgpc | dlcosmk | dscpmk | tswtclmt | tokenmt | flowacct 

params_clause ::= params { 
     parameters
     params-stats |   ""
     }
parameters ::=    prm-name-value parameters |  ""
prm_name_value ::= param-name param-value

params_stats ::= global-stats boolean

cf_clauses ::= class-clause cf-clauses |
               filter-clause cf-clauses | ""

class_clause ::= class {
     name class-name
     next_action next-action-name
     class-stats | ""
                 }
class_name  ::= string
next_action_name  ::= string
class_stats ::= enable_stats boolean
boolean ::= TRUE | FALSE

filter_clause ::= filter {
                name filter-name
                class class–name
                parameters
                }
filter_name ::= string

The remaining text describes each major part of the IPQoS configuration file.

action Statement

You use action statements to invoke the various IPQoS modules that are described in IPQoS Architecture and the Diffserv Model.

When you create the IPQoS configuration file, you must always begin with the version number. Then, you must add the following action statement to invoke the classifier:

fmt_version 1.0

action {
    module ipgpc
    name ipgpc.classify
}

Follow the classifier action statement with a params clause or a class clause.

Use the following syntax for all other action statements:

action {
name action-name
module module-name
params-clause | ""
cf-clauses
}

name action_name

Assigns a name to the action.

module module_name

Identifies the IPQoS module to be invoked, which must be one of the modules in Table 6-5.

params_clause

Can be parameters for the classifier to process, such as global statistics or the next action to process.

cf_clauses

A set of zero or more class clauses or filter clauses

Module Definitions

The module definition indicates which module is to process the parameters in the action statement. The IPQoS configuration file can include the following modules.

Table 6-5 IPQoS Modules

class Clause

You define a class clause for each class of traffic.

Use this syntax to define the remaining classes in the IPQoS configuration:

class {
     
      name class-name
      next_action next-action-name
}      

To enable statistics collection on a particular class, you must first enable global statistics in the ipgpc.classify action statement. For more information, refer to action Statement.

Use the enable_stats TRUE statement whenever you want to turn on statistics collection for a class. If you do not need to gather statistics for a class, you can specify enable_stats FALSE. Alternatively, you can eliminate the enable_stats statement.

Traffic on an IPQoS-enabled network that you do not specifically define is relegated to the default class.

filter Clause

Filters are made up of selectors that group traffic flows into classes. These selectors specifically define the criteria to be applied to traffic of the class that was created in the class clause. If a packet matches all selectors of the highest-priority filter, the packet is considered to be a member of the filter's class. For a complete list of selectors that you can use with the ipgpc classifier, refer to Table 6-1.

You define filters in the IPQoS configuration file by using a filter clause, which has the following syntax:

filter { 
       name filter-name
       class class-name 
       parameters (selectors)
       }

params Clause

The params clause contains processing instructions for the module that is defined in the action statement. Use the following syntax for the params clause:

params {
           parameters
           params-stats | ""
       }

In the params clause, you use parameters that are applicable to the module.

The params-stats value in the params clause is either global_stats TRUE or global_stats FALSE. The global_stats TRUE instruction turns on UNIX style statistics for the action statement where global statistics is invoked. You can view the statistics by using the kstat command. You must enable action statement statistics before you can enable per-class statistics.