Cisco Headend System Release 2.7
Chapter 2 SDV: The New Optional Feature in SR 4.2
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Switched Digital Video: Optimizes Bandwidth
Utilization
Utilization
Overview
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.
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.
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.
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.
separately.
Note: SDV also requires the functionality of the Netcrypt Bulk Encryptor.
An End-to-End Solution is Now Available
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.
providers that want to deploy SDV in their system. The hardware, software, and
technical expertise required to implement SDV is now available from Cisco.