An idle timeout is the maximum time that a subscriber session can be idle before the session is terminated or a connectivity check is started. Idle timeout applies to PPPoE and IPoE hosts.
The time/volume based accounting model is used to configure an idle timeout.
Create a category-map (see Category map and categories)
Define a category with queues and policers to be monitored for activity (packets being forwarded).
An activity threshold (in kb/s) must be configured for idle timeout to take effect. The activity threshold suppresses background traffic (for example control flows) from activity monitoring.
The following in an example of a category map configuration:
config>subscr-mgmt
category-map "idle-timeout" create
activity-threshold 25
category "cat-1" create
queue 1 ingress-egress
exit
exit
In the sla-profile, associate the category-map and optionally define
An idle-timeout (60 to 15552000 seconds). The default is infinite (no idle-timeout).
The idle-timeout can also be specified from RADIUS in an access-accept or CoA message with the [28] Idle-Timeout attribute. A RADIUS specified idle-timeout overrides the CLI- configured value. The values outside the limits are accepted but rounded to these boundaries.
Attribute ID | Attribute name | Type | Limits | Purpose and format |
---|---|---|---|---|
28 |
Idle-Timeout |
integer |
60 to 15552000 seconds |
0 = infinite (no idle-timeout) 60 to 15552000, in seconds For example: Idle-Timeout = 3600 |
An idle-action:
shcv-check
Perform a subscriber host connectivity check (IPoE hosts only). Host connectivity verification should be enabled on the corresponding group-interface for the idle-timeout-action shcv-check to take effect:
configure>service ies | vprn service-id subscriber-interface ip-int-name >group-interface ip-int-name>host-connectivity-verify
If the SHCV check is successful, the subscriber host is not disconnected, and the idle-timeout timer is reset to zero. If the SHCV check fails, the subscriber host is disconnected (same as terminate).
For PPP hosts, the idle-timeout-action shcv-check is ignored and has the same effect as idle-timeout-action terminate.
IPoE:
Terminate (default): disconnect the subscriber hosts
PPP:
Example
config>subscr-mgmt
sla-profile "sla-profile-1" create
category-map "idle-timeout"
category "cat-1" create
idle-timeout 3600
idle-timeout-action terminate
exit
exit
exit
At host instantiation, a timer is initialized to the idle-timeout value (one timer per sla-profile instance). Each queue or policer in the category is monitored for activity over a fixed polling interval:
During the polling interval:
When the timer becomes zero, the idle-timeout-action is performed for all hosts associated with the SLA-profile-instance (all hosts from a subscriber on a single sap and that share the same sla-profile).