Information Technology Reference
In-Depth Information
Media player module
Data delivery module
Streaming control module
Content lookup substrate
Figure 1.1
Modules within a peer of a P2P streaming system.
Content lookup
substrate
Server-based
P2P networks
Centralized
indexes
Distributed
indexes
Structured
P2P networks
Unstructured
P2P networks
Query flooding
selective
forwarding
DHT-based
others
Figure 1.2
Categories of content lookup substrates.
topology maintenance. The
data delivery module
is in charge of data exchange
among peers. The
media player module
is in charge of media playback.
Based on the way the protocols distribute and discover the content in
the content lookup substrate, P2P networks can be categorized into struc-
tured P2P networks and unstructured P2P networks (see Figure 1.2). In
structured P2P networks almost all protocols use a Distributed Hash Table
(DHT) to manage content distribution and discovery. In unstructured P2P
networks, most protocols simply flood the network with requests to dis-
cover content.
Based on the data delivery mechanisms of the networks controlled by the
streaming control layer, the P2P networks can be categorized by whether
they use tree-push, mesh-pull, or push-pull methods (see Figure 1.3).
