This section introduces IPQoS configuration file creation by showing how to create a configuration file for a premium web server. The section then shows how to configure a completely different level of service in another configuration file for a server that hosts personal web sites. Both servers are part of the network example that is shown in Figure 2–4.
The following configuration file defines IPQoS activities for the Goldweb server, which hosts the web site for Goldco, the company that has purchased a premium SLA.
fmt_version 1.0 action { module ipgpc name ipgpc.classify params { global_stats TRUE } class { name goldweb next_action markAF11 enable_stats FALSE } class { name video next_action markEF enable_stats FALSE } filter { name webout sport 80 direction LOCAL_OUT class goldweb } filter { name videoout sport videosrv direction LOCAL_OUT class video } } action { module dscpmk name markAF11 params { global_stats FALSE dscp_map{0-63:10} next_action continue } } action { module dscpmk name markEF params { global_stats TRUE dscp_map{0-63:46} next_action acct } } action { module flowacct name acct params { enable_stats TRUE timer 10000 timeout 10000 max_limit 2048 } }
The following configuration file defines IPQoS activities on Userweb, which hosts web sites for individuals with low-priced, or best-effort, SLAs. This SLA level guarantees the best service that can be delivered to best-effort customers after the IPQoS system handles traffic from customers with more expensive SLAs.
fmt_version 1.0 action { module ipgpc name ipgpc.classify params { global_stats TRUE } class { name Userweb next_action markAF12 enable_stats FALSE } filter { name webout sport 80 direction LOCAL_OUT class Userweb } } action { module dscpmk name markAF12 params { global_stats FALSE dscp_map{0-63:12} next_action continue } }
You can create your first IPQoS configuration file in whatever directory is easiest for you to maintain and use. The tasks in this chapter use the directory /var/ipqos as the location for IPQoS configuration files. The next procedure builds the initial segment of the IPQoS configuration file that is introduced in Example 3–1.
As you create the IPQoS configuration file, be very careful to start and end each action statement and clause with curly braces ({ }). For an example of the use of braces, see Example 3–1.
Log in to the premium web server, and create a new IPQoS configuration file with a .qos extension.
Every IPQoS configuration file must start with the version number fmt_version 1.0 as its first uncommented line.
Follow the opening parameter with the initial action statement, which configures the generic IP classifier ipgpc.
This initial action begins the tree of action statements that compose the IPQoS configuration file. For example, the /var/ipqos/Goldweb.qos file begins with the initial action statement to call the ipgpc classifier.
fmt_version 1.0 action { module ipgpc name ipgpc.classify |
Entry |
Description |
---|---|
fmt_version 1.0 |
Begins the IPQoS configuration file |
action { module ipgpc |
Configures the ipgpc classifier as the first action in the configuration file |
name ipgpc.classify |
Defines the name of the classifier action statement, which must always be ipgpc.classify |
For detailed syntactical information about action statements, refer to action Statement and theipqosconf(1M) man page.
Add a params clause with the statistics parameter global_stats.
params { global_stats TRUE } |
The parameter global_stats TRUE in the ipgpc.classify action enables statistics taking for that action. global_stats TRUE also enables per-class statistics taking wherever a class clause definition specifies enable_stats TRUE.
Turning on statistics impacts performance. You might want to take statistics on a new IPQoS configuration file to verify that IPQoS works properly. Later, you can turn off statistics collection by changing the argument to global_stats to FALSE.
Global statistics are but one type of parameter you can define in a params clause. For syntactical and other details about params clauses, refer to Params Clause and the ipqosconf man page.
Define a class that identifies traffic that is bound for the premium server.
class { name goldweb next_action markAF11 enable_stats FALSE } |
The previous statement is called a class clause. A class clause has the following contents.
Entry |
Description |
---|---|
name goldweb |
Creates the class goldweb to identify traffic that is bound for the Goldweb server. |
next_action markF11 |
Instructs the ipgpc module to pass packets of the goldweb class to the markAF11 action statement. The markAF11 action statement calls the dscpmk marker. |
enable_stats FALSE |
Enables statistics taking for the goldweb class. However, because the value of enable_stats is FALSE, statistics for this class are not turned on. |
For detailed information about the syntax of the class clause, see Class Clause and the ipqosconf(1M) man page.
Define a class that identifies an application that must have highest-priority forwarding.
class { name video next_action markEF enable_stats FALSE } |
Entry |
Description |
---|---|
name video |
Creates the class video to identify streaming video traffic that is outgoing from Goldweb. |
next_action markEF |
Instructs the ipgpc module to pass packets of the video class to the markEF action statement after ipgpc completes processing. The markEF action statement calls the dscpmk marker. |
enable_stats FALSE |
Enables statistics taking for the video class. However, because the value of enable_stats is FALSE, statistics for this class are not turned on. |
Task |
For Information |
---|---|
Define filters for the class you just created | |
Create another class clause for the configuration file |
How to Begin the IPQoS Configuration File and Define Traffic Classes |
The next procedure shows how to define filters for a class in the IPQoS configuration file. The procedure assumes that you have already begun the file and have defined classes. The steps continue building the /var/ipqos/Goldweb.qos file that is introduced in How to Begin the IPQoS Configuration File and Define Traffic Classes.
As you create the IPQoS configuration file, be very careful to start and end each class clause and filter clause with curly braces ({ }). For an example of the use of braces, use Example 3–1.
Open the IPQoS configuration file, and locate the end of the last class that you defined.
For example, on the IPQoS-enabled server Goldweb you would start after the following class clause in /var/ipqos/Goldweb.qos.
class { name video next_action markEF enable_stats FALSE } |
Define a filter clause to select outgoing traffic from the IPQoS system.
filter { name webout sport 80 direction LOCAL_OUT class goldweb } |
Entry |
Description |
---|---|
name webout |
Gives the name webout to the filter |
sport 80 |
Selects traffic with a source port of 80, the well-known port for HTTP (Web) traffic |
direction LOCAL_OUT |
Further selects traffic that is outgoing from the local system |
class goldweb |
Identifies the class to which the filter belongs, in this instance, class goldweb |
For syntactical and detailed information about the filter clause in the IPQoS configuration file, refer to Filter Clause.
Define a filter clause to select streaming video traffic on the IPQoS system.
filter { name videoout sport videosrv direction LOCAL_OUT class video } |
Entry |
Description |
---|---|
name videoout |
Gives the name videoout to the filter |
sport videosrv |
Selects traffic with a source port of videosrv, a previously defined port for the streaming video application on this system |
direction LOCAL_OUT |
Further selects traffic that is outgoing from the local system |
class video |
Identifies the class to which the filter belongs, in this instance, class video |
Task |
For Information |
---|---|
Define forwarding behaviors for the marker modules |
How to Define Traffic Forwarding in the IPQoS Configuration File |
Define flow-control parameters for the metering modules |
How to Configure Flow Control in the IPQoS Configuration File |
Activate the IPQoS configuration file |
How to Apply a New Configuration to the IPQoS Kernel Modules |
Define additional filters | |
Create classes for traffic flows from applications |
How to Configure the IPQoS Configuration File for an Applications Server |
The next procedure shows how to define traffic forwarding by adding per-hop behaviors for a class into the IPQoS configuration file. The procedure assumes that you have an existing IPQoS configuration file with already-defined classes and filters. The steps continue building the /var/ipqos/Goldweb.qos file from Example 3–1.
The procedure shows how to configure traffic forwarding by using the dscpmk marker module. For information about traffic forwarding on VLAN systems by using the dlclosmk marker, refer to Using the dlcosmk Marker With VLAN Devices.
Open the IPQoS configuration file, and locate the end of the last filter you defined.
For example, on the IPQoS-enabled server Goldweb, you would start after the following filter clause in /var/ipqos/Goldweb.qos.
filter { name videoout sport videosrv direction LOCAL_OUT class video } } |
Note that this filter is at the end of the ipgpc classifier action statement. Therefore, you need a closing brace to terminate the filter and a second closing brace to terminate the action statement.
Invoke the marker with the following action statement.
action { module dscpmk name markAF11 |
Entry |
Description |
---|---|
module dscpmk |
Calls the marker module dscpmk |
name markAF11 |
Gives the name markAF11 to the action statement |
The previously defined class goldweb includes a next_action markAF11 statement. This statement sends traffic flows to the markAF11 action statement after the classifier concludes processing.
Define actions for the marker to take on the traffic flow.
params { global_stats FALSE dscp_map{0-63:10} next_action continue } } |
Entry |
Description |
---|---|
global_stats FALSE |
Enables statistics taking for the markAF11 marker action statement. However, because the value of enable_stats is FALSE, statistics are not turned on. |
dscp_map{0–63:10} |
Assigns a DS codepoint of 10 to the packet headers of the traffic class goldweb, which is currently being processed by the marker. |
next_action continue |
Indicates that no further processing is required on packets of the traffic class goldweb, and that these packets can return to the network stream. |
The DS codepoint 10 instructs the marker to set all entries in the dscp map to the decimal value 10 (binary 001010). This codepoint indicates that packets of the goldweb traffic class are subject to the AF11 per-hop behavior. AF11 guarantees that all packets with DS codepoint 10 receive a low-drop, high-priority service. Thus, outgoing traffic for premium customers on Goldweb is given the highest priority available for the Assured Forwarding PHB. For a table of possible DS codepoints for AF, refer to Table 6–2.
Start another marker action statement.
action { module dscpmk name markEF |
Entry |
Description |
---|---|
module dscpmk |
Calls the marker module dscpmk |
name markEF |
Gives the name markEF to the action statement |
Define actions for the marker to take on the traffic flow.
params { global_stats TRUE dscp_map{0-63:46} next_action acct } } |
Entry |
Description |
---|---|
global_stats TRUE |
Enables statistics taking on class video, which selects streaming video packets. |
dscp_map{0–63:46} |
Assigns a DS codepoint of 46 to the packet headers of the traffic class video, which is currently being processed by the marker. |
next_action acct |
Instructs the dscpmk module to pass packets of the video class to the acct action statement after dscpmk completes processing. The acct action statement invokes the flowacct module. |
The DS codepoint 46 instructs the dscpmk module to set all entries in the dscp map to the decimal value 46 (binary 101110) in the DS field. This codepoint indicates that packets of the video traffic class are subject to the EF per-hop behavior.
The recommended codepoint for EF is 46 (binary 101110). Other DS codepoints assign AF PHBs to a packet.
The EF PHB guarantees that packets with the DS codepoint of 46 are given the highest precedence by IPQoS and diffserv-aware systems. Streaming applications require highest-priority service, which is the rationale behind assigning them EF PHBs in the QoS policy. For more details about the expedited forwarding PHB, refer to Expedited Forwarding (EF) PHB.
Add the DS codepoints that you have just created to the appropriate files on the diffserv router. For more information, refer to How to Configure a Router on an IPQoS-Enabled Network.
Task |
For Information |
---|---|
Start gathering flow-accounting statistics on traffic flows |
How to Enable Accounting for a Class in the IPQoS Configuration File |
Define forwarding behaviors for the marker modules |
How to Define Traffic Forwarding in the IPQoS Configuration File |
Define flow-control parameters for the metering modules |
How to Configure Flow Control in the IPQoS Configuration File |
Activate the IPQoS configuration file |
How to Apply a New Configuration to the IPQoS Kernel Modules |
Define additional filters | |
Create classes for traffic flows from applications |
How to Configure the IPQoS Configuration File for an Applications Server |
The next procedure shows how to enable accounting on a traffic class in the IPQoS configuration file. The procedure assumes that you have an existing IPQoS configuration file with already-defined classes, filters, metering actions, if appropriate, and marking actions, if appropriate. The steps continue building the /var/ipqos/Goldweb.qos file from Example 3–1.
The procedure shows how to define flow accounting for the video class, which is introduced in How to Begin the IPQoS Configuration File and Define Traffic Classes. This class selects streaming video traffic, which must be billed as part of a premium customer's SLA.
Open the IPQoS configuration file, and locate the end of the last action statement you defined.
For example, on the IPQoS-enabled server Goldweb, you would start after the following markEF action statement in /var/ipqos/Goldweb.qos.
action { module dscpmk name markEF params { global_stats TRUE dscp_map{0-63:46} next_action acct } } |
Begin an action statement that calls flow accounting.
action { module flowacct name acct |
Entry |
Description |
---|---|
module flowacct |
Invokes the flow-accounting module flowacct |
name acct |
Gives the name acct to the action statement |
Define a params clause to control accounting on the traffic class.
params { global_stats TRUE timer 10000 timeout 10000 max_limit 2048 next_action continue } } |
Entry |
Description |
---|---|
global_stats TRUE |
Enables statistics taking on class video, which selects streaming video packets. |
timer 10000 |
Specifies the duration of the interval, in milliseconds, when the flow table is scanned for timed out flows. In this parameter, that interval is 10000 milliseconds. |
timeout 10000 |
Specifies the minimum interval time-out value. A flow “times out” when packets for the flow are not seen during a time-out interval. In this parameter, packets time out after 10000 milliseconds. |
max_limit 2048 |
Sets the maximum number of active flow records in the flow table for this action instance. |
next_action continue |
Indicates that no further processing is required on packets of the traffic class video, and that these packets can return to the network stream. |
The flowacct module gathers statistical information on packet flows of a particular class until a specified timeout value is reached.
Task |
For Information |
---|---|
Configure per-hop behaviors on a router | |
Activate the IPQoS configuration file |
How to Apply a New Configuration to the IPQoS Kernel Modules |
Create classes for traffic flows from applications |
How to Configure the IPQoS Configuration File for an Applications Server |
The IPQoS configuration file for a best-effort web server differs slightly from an IPQoS configuration file for a premium web server. The following procedure illustrates the similarities and differences between configuration files for the varying levels of web service. As an example, the procedure uses the configuration file from Example 3–2.
Log in to the best-effort web server.
Create a new IPQoS configuration file with a .qos extension.
fmtversion 1.0 action { module ipgpc name ipgpc.classify params { global_stats TRUE } |
The /var/ipqos/userweb.qos file must begin with the partial action statement to invoke the ipgpc classifier. In addition, the action statement also has a params clause to turn on statistics taking. For an explanation of this action statement, see How to Begin the IPQoS Configuration File and Define Traffic Classes.
Define a class that identifies traffic that is bound for the best-effort web server.
class { name userweb next_action markAF12 enable_stats FALSE } |
Entry |
Description |
---|---|
name userweb |
Creates a class that is called userweb for forwarding web traffic from users. |
next_action markF12 |
Instructs the ipgpc module to pass packets of the userweb class to the markAF12 action statement after ipgpc completes processing. The markAF12 action statement invokes the dscpmk marker. |
enable_stats FALSE |
Enables statistics taking for the userweb class. However, because the value of enable_stats is FALSE, statistics for this class are not turned on. |
For an explanation of the class clause task, see How to Begin the IPQoS Configuration File and Define Traffic Classes.
Define a filter clause to select traffic flows for the userweb class.
filter { name webout sport 80 direction LOCAL_OUT class userweb } } |
Entry |
Description |
---|---|
name webout |
Gives the name webout to the filter |
sport 80 |
Selects traffic with a source port of 80, the well-known port for HTTP (Web) traffic |
direction LOCAL_OUT |
Further selects traffic that is outgoing from the local system |
class userweb |
Identifies the class to which the filter belongs, in this instance, class userweb |
For an explanation of the filter clause task, see How to Define Filters in the IPQoS Configuration File.
Begin the action statement to invoke the dscpmk marker.
action { module dscpmk name markAF12 |
Entry |
Description |
---|---|
module dscpmk |
Invokes the marker module dscpmk |
name markAF11 |
Gives the name markAF12 to the action statement |
The previously defined class userweb includes a next_action markAF12 statement. This statement sends traffic flows to the markAF12 action statement after the classifier concludes processing.
Define parameters for the marker to use for processing the traffic flow.
params { global_stats FALSE dscp_map{0-63:12} next_action continue } } |
Entry |
Description |
---|---|
global_stats FALSE |
Enables statistics taking for the markAF12 marker action statement. However, because the value of enable_stats is FALSE, statistics are not turned on. |
dscp_map{0–63:12} |
Assigns a DS codepoint of 12 to the packet headers of the traffic class userweb, which is currently being processed by the marker. |
next_action continue |
Indicates that no further processing is required on packets of the traffic class goldweb, and that these packets can return to the network stream. |
The DS codepoint 12 instructs the marker to set all entries in the dscp map to the decimal value 12 (binary 001100). This codepoint indicates that packets of the userweb traffic class are subject to the AF12 per-hop behavior. AF12 guarantees that all packets with DS codepoint 12 in the DS field receive a medium-drop, high-priority service.
When you complete the IPQoS configuration file, apply the configuration, as described in How to Apply a New Configuration to the IPQoS Kernel Modules.
Task |
For Information |
---|---|
Add classes and other configuration for traffic flows from applications |
How to Configure the IPQoS Configuration File for an Applications Server |
Configure per-hop behaviors on a router | |
Activate your IPQoS configuration file |
How to Apply a New Configuration to the IPQoS Kernel Modules |