Specifications

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Cisco TV CDS 2.5 ISA Software Configuration Guide
OL-24788-01
Chapter 1 Product Overview
Overview
in the local cache of the Streamer are pulled from the Vault, cached on the Streamer, and streamed to the
subscriber. Wherever the content is stored relative to the point of playout, all content appears as if it is
local to the Streamer and the streaming of any content is nearly instantaneous.
Caching Nodes
A Caching Node is an intermediary fill source for the Streamers. Caching Nodes are deployed in Virtual
Video Infrastructures (VVIs). The VVI is a deployment type of the TV CDS. In a CDS, servers cannot
communicate with servers in other groups. In a VVI, servers in other groups can communicate with each
other on an as needed basis. Streamers and Caching Nodes dynamically discover fill sources within other
groups. Streamers send cache-fill calls to remote servers (Streamers in other Stream Groups and Caching
Nodes) for content that is not found locally (DRAM, disk cache, or peer Streamers). In a VVI, the
Caching Nodes can communicate with the Streamers by using CCP or HTTP. For more information on
how a Caching Node interfaces with a CCP Streamer and an HTTP Streamer, see the “Caching Node
Workflow” section on page 2-10.
Streamer Load Balancing
To ensure that new streams are distributed to the best Streamer in the group, each Stream Group runs a
load distribution protocol among its members. The best Streamer is the Streamer that has the requested
content in the highest-performing cache resource (DRAM or disk) or that has the most unused capacity.
In this way, new Streamers are brought into operation hitlessly—because after a new server is in service,
fresh streams are automatically allocated to it. Furthermore, the cache capacity of the group is the sum
of the caches of all Streamers in the group, which provides the most optimal system operation and the
highest cache-hit rate.
CServer Functionality
The CServer is responsible for the following:
• Storing content
• Streaming content
• Managing bandwidth usage for ingests
• Managing bandwidth usage for streaming
• Mirroring content among Vault servers
• Making decisions on content retention on Streamer servers
Streamer Content Delivery Applications
On top of the CServer, and taking advantage of the services it offers, a variety of applications deliver
individual personalized entertainment services. Cisco currently offers the following applications:
• TV Streamer delivering VOD and network personal video recorder (nPVR) services
• TV MediaX Suite for simplifying ingest and workflow scheduling tasks for asset-based and
real-time content
In a full TV CDS network, the Vault, TV Streamer, and CDSM are required. The TV MediaX Suite is an
optional CDA. In a smaller TV CDS network, the ISV can be used in place of the Vault and TV Streamer.