Configuring QoS for L2TP Interfaces
The JUNOSe software supports QoS queues and scheduler nodes for L2TP session interfaces. L2TP QoS provides per-L2TP session queuing and allows QoS profiles to be dynamically attached to L2TP session interfaces on E-series routers. The routers can be configured as either an LAC or LNS.
The dynamic attachment process uses RADIUS and AAA, enabling a QoS profile to be attached to a dynamic L2TP session interface when the newly created interface has the QoS-Profile-Name [26-26] RADIUS VSA associated with it. L2TP QoS support gives you the ability to shape tunneled users through L2TP interfaces.
L2TP QoS profiles are attached at the L2TP session interface, except on the LNS with nonmultilink interfaces. On the LNS with nonmultilink interfaces, L2TP QoS profiles are attached at the IP interface. The queues and scheduler node are built at the L2TP client interface on the line module.
L2TP session interfaces have default QoS profiles and scheduler nodes. The default configuration includes the following settings:
host1(config)#show qos-profile l2tp-session-default
t-class interface rule traffic scheduler queue drop statistics
group type type class profile profile profile profile
-------- ------------ ----- ----------- --------- ------- ------- ----------
l2tp-session queue best-effort default default default default
Configuration Procedure
This section describes a sample procedure that configures L2TP QoS. The configuration steps are identical for QoS on an LAC or an LNS; however, the resulting scheduler hierarchy depends on the type of environment. Scheduler Hierarchies shows the scheduler hierarchies that the configuration example would create for different environments.
The following example assumes that the traffic class (voice) and the two scheduler profiles (100k, and 400k) have already been created.
- (Optional) This step is required if you are configuring QoS on an LNS; it is not required for QoS on an LAC.
Remove the best-effort traffic class rule from the IP interface type of the server-default QoS profile; this enables you to create L2TP session queues.
host1(config)#qos-profile server-default
host1(config-qos-profile)#no ip queue traffic-class best-effort
host1(config-qos-profile)#exit
- Create a traffic-class group, and enter Traffic Class Group Configuration mode. Add the traffic class voice to the new group.
- Configure the QoS profile.
host1(config)#traffic-class-group tcGroup1
host1(config-traffic-class-group)#traffic-class voice
host1(config-traffic-class-group)#exit
- Create the QoS profile, and enter QoS Profile Configuration mode.
- Add two queues for L2TP session interfaces to the QoS profile.
host1(config)#qos-profile l2tpQpro25
host1(config-qos-profile)#
host1(config-qos-profile)#lt2p-session queue traffic-class best-effort
scheduler-profile 400k
host1(config-qos-profile)#lt2p-session queue traffic-class voice scheduler-profile
100k
host1(config-qos-profile)#exit
host1(config)#
- (Optional) Verify the new QoS profile configuration.
host1(config)#show qos-profile l2tpQpro25
qos-profile l2tpQpro25:
t-class interface rule traffic scheduler queue drop statistics
group type type class profile profile profile profile
-------- --------- ----- ----------- --------- ------- ------- ----------
l2tp-session queue best-effort 400k default default default
tcGroup1 l2tp-session queue voice 100k default default default
Scheduler Hierarchies
This section shows the different scheduler hierarchies that might be built by the procedure shown in Configuration Procedure. The type of networking architecture in which the QoS profile is used determines the actual hierarchy that is built. Figure 28 through Figure 32 show scheduler hierarchies for different networking architectures.
