Specifications

2-4
Cisco TV CDS 2.5 ISA Software Configuration Guide
OL-24788-01
Chapter 2 Network Design
TV CDS and VVI Topologies
Figure 2-3 illustrates the centralized topology for a VVI.
Figure 2-3 Centralized Topology with Caching Nodes
Decentralized Topology
The decentralized topology is a hub-and-spoke topology between the headend site and multiple hub
sites, where the Vaults are located at the headend and the Streamers are in the hub sites. For a VVI, a
decentralized topology provides a three-tiered approach by having the Vaults located in the headend, the
Caching Nodes in intermediary sites, and the Streamers in the hub sites. The decentralized topology
works well for distributing Stream Groups close to subscribers. A decentralized topology has advantages
in reducing the amount of long-haul fiber transport bandwidth needed—typically by a factor of ten or
better. Figure 2-4 illustrates the decentralized topology.
Figure 2-4 Decentralized Topology
Caching Nodes
Vaults
GE Switch
GE Switch
GE Switch
GE QAMs
Streamers
Headend or Remote Hub
HFC
252114
203090
Headend
Storage Content
Vaults
GE QAMs
Remote Hub 1
Streamers
HFC
GE QAMs
Remote Hub 2
Streamers
Switch
Network
HFC
Switch
Network
Switch
Network