Specifications

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Cisco TV CDS 2.5 ISA Software Configuration Guide
OL-24788-01
Chapter 2 Network Design
TV CDS and VVI Topologies
to the quadrature amplitude modulation (QAM) devices over gigabit Ethernet or asynchronous serial
interface (ASI), and then is modulated onto the HFC plant to the subscriber set-top box (STB) for
viewing.
CDS with ISVs
For the smallest networks, Cisco packages the CDS in a single server, the Integrated Streamer-Vault
(ISV), offering a solution for VOD services with large content libraries but small stream counts.
In a TV CDS with ISVs, MPEG-2 TS video is stored on the ISVs with the associated trick-mode files.
Content is sent unicast from the ISVs and delivered to the QAM devices over a gigabit Ethernet network,
and then is modulated onto the HFC plant to the subscriber STB for viewing.
CDS with Caching Nodes
For larger networks, Cisco offers the CDS with Caching Nodes in the Virtual Video Infrastructure (VVI).
In a VVI, Caching Nodes are the intermediary fill source for Streamers, which removes a large portion
of the distribution traffic from the Vaults.
In a TV VVI, MPEG-2 TS video is stored on the Vaults with the associated trick-mode files. Content is
transported from the Vaults to the Caching Nodes as needed, by using CCP over gigabit Ethernet
networks. Content is distributed from the Caching Nodes to the Streamers as needed, by using CCP over
gigabit Ethernet networks, or by using HTTP over gigabit Ethernet networks. Content is sent unicast
from the Streamers and delivered to the QAM devices over a gigabit Ethernet network, and then is
modulated onto the HFC plant to the subscriber STB for viewing.
TV CDS and VVI Topologies
The TV CDS (using Vaults and Streamers, or ISVs) and the TV VVI (using Vaults, Caching Nodes, and
Streamers), supports centralized, decentralized, and hybrid gigabit Ethernet network designs. Because
the use of Vaults and Streamers separates storage from streaming, streaming requirements can be
satisfied on an as-needed basis and the streaming can be centralized or distributed among multiple
locations. Caching Nodes separate the ingest and storage of content from the distribution of content,
offering greater flexibility and network efficiency.
The TV CDS topology and TV VVI topology can change with the evolving needs of the system operator.
If the need to decentralize becomes evident, you can move the Streamers or Vaults to remote hubs
without disrupting service. The VVI offers additional flexibility in designing your network. Vaults can
be centrally located at a national network, and content may be classified by market (city, state, or a
broader region) depending on the AMS or BMS used. Caching Nodes can be located centrally, or
distributed closer to the regional networks where the Streamers are located. Using Caching Nodes in the
network design takes the distribution traffic off the network backbone.
Caution All Cisco servers are connected through a switch. Because all Vaults, CCP Streamers, and Caching
Nodes in the same array exchange heartbeat messages through the cache interfaces, it is important to
ensure there is enough bandwidth among switches involved in delivering cache traffic, as well as to
support the same aggregated amount of traffic on all cache interfaces.