Cisco DNCS System Release 2.8.1 3.8.1 4.3.1 User Guide

Important: The DSG Timer user interface is intended for use by operators with DOCSIS network experience. If
you need more detailed information on Basic DSG, please review the DOCSIS Set-top Gateway (DSG)
Interface Specification, which you can access from the CableLabs® website (

).

The Client Filters user interface allows you to change any of the pre-configured timer settings in the global
default DCD (Downstream Channel Descriptor) file. These settings define the overall amount of time a set-top's
embedded cable modem waits to receive DSG packets. Timer settings are pre-configured with recommended
default values and are applicable to any system running basic DSG, including systems that use the PowerKEY®
CA method and systems using a third-party CA method.

Follow these steps to change timer settings for basic DSG.

1.

On the DNCS Administrative Console, click the Application Interface Modules tab.

2.

Click Client Filters. The Rules for Client Filters window opens.

3.

Click Configuration. The Configuration for Client Filters window opens.

4.

Update the timer settings as necessary. The following list provides a brief description of each setting.



DSG Initialization Timeout (TDSG1) - The time the DHCT's embedded cable modem (also

known as the eCM) stays on a DOCSIS channel during initialization, waiting for DSG packets to
arrive from the CMTS. If DSG packets are not received within this time period, the DOCSIS
channel is declared invalid, and the set-top does not lock on a particular DOCSIS channel. The
default value is 2 seconds. You cannot set this timer to 0.



DSG Operational Timeout (TDSG2) - The time allowed for DSG packets to reach the

set-top's embedded cable modem during normal operation. If DSG packets do not arrive within
this time period, the DSG One-Way retry Timer (TDSG4) is activated. The default value for
TDSG2 is 600 seconds. You cannot set this timer to 0.



DSG Two-Way retry Timer (TDSG3) - The time the set-top's embedded cable modem waits

before trying to re-establish two-way connectivity with the CMTS while the embedded cable
modem is in a one-way operational state. The default value is 300 seconds. You cannot set this
timer to 0.

Note: "One-way" and "Two-way" in these descriptions refer to the state of the embedded cable
modem, not the operational state of the set-top.



DSG One-Way retry Timer (TDSG4) - Determines how long the set-top's embedded cable

modem waits to rescan for a DOCSIS downstream channel that contains DSG packets after an
operational timeout occurs. If this time period expires, the DOCSIS channel is declared invalid
and the DHCT's embedded cable modem will scan for another DOCSIS channel. The default
value is 1800 seconds. You cannot set this timer to 0.

5.

When you have finished updating the settings, click Save. The DCD file is updated with the values and

reloaded on the BFS.

