P2P Network Architectures - Peer-to-Peer Computing: Applications, Architecture, Protocols, and Challenges - page 50

Requesting Peer

Broadband Network

User
Interface

Server for Multiple Independent Nodes

Admission
Control

Request
Manager

Partial Video
Object
Indexing

QoS
Manager

Query
Manager

Data

Memory
for Video
Objects

Storage
Manager

Multimedia
Indexing

Data Data Data

Data

FIGURE 3.17: The MIIS network architecture [Kalogeraki et al., 2003].

Thirdly, the reliability of different architectures was tested by measuring
the number of video objects that became unavailable as servers/peers failed.
As expected, the FAMS architecture was the most reliable. On the other hand,
as time evolved, the reliability of the MIIS architecture gradually improved.
This was because the replication algorithm gradually cached more copies of
popular video objects.
Fourthly, Kalogeraki et al. also investigated the scalability of the architec-
ture as a measure of the number of user requests rejected. In the SIMS/MIMS
architecture, the indexing servers/peers can become a performance bottleneck
as the number of user requests increases. However, the servers/peers provide
QoS guarantees if the requests are admitted. Obviously, in the FAMS archi-
tecture, the number of rejected requests is very small, at the expense of having
slow connections.

3.7 Case Study: PPLive
The PPLive network is unstructured and is found to be similar to random
graphs [Hei et al., 2007a, Vu et al., 2010]. Moreover, in the PPLive mesh
network, the average node degree (i.e., number of peers in the neighbor list) is