Cisco Cisco Digital Service Access Node (DSAN) 8211 Installation Guide

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Chapter 2    Introduction 
 
 
 
34 
OL-29938-01 
Emergency Alert System Support 
This section describes the Emergency Alert System (EAS) support and operation for 
the DSAN device. 
Distribution and Triggering 
The DSAN unit supports EAS signaling via the SCTE-18 standard. The signaling is 
distributed to the DSAN device in-band via QAM channel. The DSAN unit 
continuously monitors the QAM associated with the first configured demodulator 
on the first configured wide-band tuner for SCTE-18 data to trigger an emergency 
event. 
Notification Method 
The DSAN unit supports EAS notification via force tuning of specified output 
channels to a particular details channel. The details channel is specified in the SCTE-
18 data in the details_major_channel_number and details_minor_channel_number 
parameter. Scrolling text and audio overlay are not supported due to the 
complexities of insertion to a high number of analog output channels by the device. 
Typical provisioning of the DSAN device should include the details channel 
specified in the SCTE-18 data as one of the 82 existing provisioned services on the 
output. If the details channel is not one of the 82 provisioned services or is zero, the 
default EAS output channel will be used. This can be set using SNMP or the CLI. 
In the event that the details channel in SCTE-18 or the default channel is not a 
provisioned service, the unit will ignore the EAS message, enter an alarm condition 
indicating a failure to tune to the specified output channel, and then send a trap 
indicating the failure. 
Note: The default EAS force tune output channel must be configured during 
installation as a valid, provisioned channel, or must be disabled by setting to zero. 
An alarm condition will persist until this configuration option is set. 
Exception Channel Handling 
To support exception channels, the details channel has to be one of the 82 existing 
provisioned services on the output. Exemptions to force tuning may be specified by 
including exception_major_channel_number and exception_minor_channel_number 
parameters in the SCTE-18 message.  The exception_major_channel_number represents 
the EIA channel frequency and exception_minor_channel_number represents the 
program number.  Since EAS messages are carried in-band,  
exception_OOB_Source_ID
 parameters are not used to determine exception channels 
per SCTE-18 specification.