Cisco Headend System Release 2.7 Release Notes

 

34 

4012157 Rev B 

The growth in service bandwidth available to the service provider has far outpaced 
the increases in available access network bandwidth. This growth is due, in part, to 
upgrades and rebuilds. This same expansion of available services has also created a 
situation in which, at any given time and in any given service group, most services 
are not being viewed. Thus, bandwidth for an edge device (for example, a QAM 
modulator) and access network bandwidth is wasted because many of the services 
that are continuously broadcast to subscribers are not being watched. SDV is a 
technique that recaptures such potentially wasted access network bandwidth by 
delivering selected services only where and when users are actively requesting 
service. This technique is performed through program switching. 

SDV is an optional feature in SR 4.2 that optimizes bandwidth utilization at edge 
devices delivering content to cable network subscribers. Implementation of SDV in 
the Cisco DBDS network utilizes technology that ensures efficient sharing of QAM 
bandwidth between VOD and SDV services.  

As a new DBDS technology, SDV imposes requirements on the following existing 
DBDS elements: DNCS, GQAM, and DHCT. These elements all interact with a new 
element of the DBDS—the SDV Server. 

Important! SDV is an optional feature that must be purchased and installed 
separately. 

Note: SDV also requires the functionality of the Netcrypt Bulk Encryptor. 

With the release of SR 4.2, Cisco is able to provide an end-to-end solution for service 
providers that want to deploy SDV in their system. The hardware, software, and 
technical expertise required to implement SDV is now available from Cisco.