Cisco Headend System Release 2.7 User Guide

 

4019781 Rev B 

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Switched digital video (SDV) is a technology that allows cable operators to recover 
bandwidth from infrequently-viewed channels, by making these channels “on-
demand.” Instead of sending all channels to the set-top boxes, lightly viewed 
channels are put into a switching pool and only sent to the set-top boxes when 
viewers tune to them. 

This guide provides procedures to help you keep your SDV system running as 
expected. This guide explains various tools that you can use to monitor and 
troubleshoot SDV systems. 

The procedures in this document only apply to Digital Broadband Delivery System 
(DBDS) networks operating with the Cisco Resident Application (SARA). 

The Digital Network Control System (DNCS) must meet the following conditions to 
support SDV: 

 

Must run System Release (SR) 2.7/3.7 or SR 4.2 Service Pack 2 (SP2), or later 

 

Must have SDV feature enabled for DNCS 

 

Must have SDV feature enabled for the Netcrypt Bulk Encryptor 

 

SSP 2.3 Compliant 

For each SDV-enabled service group, a mini-carousel discovery file is created. Each 
BFS carousel is limited to 475 individual files; and therefore, before SR 2.7/3.7/4.2 
SP2, the number of SDV-enabled service groups available on the DNCS was limited 
to 475.  

A new feature in SR 2.7/3.7/4.2 SP2 allows the DNCS, by default, to create four 
additional BFS sources to deliver the mini-carousel discovery files. This 
enhancement provides for a default total of five carousels, or up to 2,375 SDV-
enabled service groups. See Expand the Number of Available Service Groups  
(on page 11) for additional information.