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Cisco Broadband Cable Command Reference Guide
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Chapter 2 Cisco CMTS Configuration Commands
cable service flow inactivity-threshold
cable service flow inactivity-threshold
To set the inactivity threshold value for service flows using Unsolicited Grant Service with Activity
Detection (UGS-AD), use the
cable service flow inactivity-threshold
command in global configuration
mode. To disable the inactivity timer and reset the threshold limit timer to its default of 10 seconds, so
that service flows revert to UGS activity only, use the
no
form of this command.
cable service flow inactivity-threshold
n
no cable service flow inactivity-threshold
n
Syntax Description
Defaults
The default is to enable the inactivity timer, with a default value of 10 seconds.
Command Modes
Global configuration
Command History
Usage Guidelines
DOCSIS 1.1 allows a CM to request Unsolicited Grant Service (UGS) for an upstream, allowing the CM
to reserve a certain amount of Constant Bit Rate (CBR) bandwidth for real-time traffic, such as Voice-
over-IP (VoIP) calls. The UGS-AD variation allows the CMTS to switch a service flow to Real Time
Polling Service (RTPS) after a certain period of inactivity, so that bandwidth is not reserved when it is
not needed. The CM can then request UGS service when the flow again becomes active.
Note
This command replaced the
cable service-flow inactivity-timeout
command, which was used in
DOCSIS 1.0 operation to enable or disable watchdog cleanup of dynamic service flows that are not
sending any packets on the upstream.
The
cable service flow inactivity-threshold
command sets the inactivity timer for how long a service
flow must be inactive before the CMTS can switch it from UGS-AD to RTPS. The
no cable service flow
inactivity-threshold
command disables the timer and resets it to its default value of 10 seconds, so that
the CMTS always provides UGS service to the service flow, even when the flow is idle.
Caution
The
no cable service flow inactivity-threshold
command effectively disables the use of RTPS and
USG-AD services and configures the CMTS to provide only UGS services. This will prevent a CM that
registered for USG-AD services from being able to obtain upstream transmission opportunities, resulting
in a significant loss of bandwidth when a large number of CMs are requesting UGS-AD service flows.
n
Specifies the threshold limit in seconds, with 10 seconds as the default.
Configurable limits are 1 to 3600 seconds.
Release
Modification
12.1(4)CX
This command replaced the
cable service-flow inactivity-timeout
command for DOCSIS 1.1 operation.
12.2(4)BC1
Support for this command was added to the Release 12.2 BC train.