Information Technology Reference
In-Depth Information
1.3.1 Structured Peer-to-Peer Networks
Structured P2P networks are mostly based on different arrangements of a
DHT. Hash tables are data structures designed for efficient search [18]. The
DHTs are a distributed version of hash tables, where all participating hosts
keep part of all the entries of the hash table [25-30].
1.3.1.1 Distributed Hash Table (DHT)
In the DHT implementation, an end host would pass a message
X
(e.g., IP
address) to a hash function to get a key
H(X)
. The content object
Y
would also
be passed to the hash function to get a key
H(Y)
. The content object
Y
would
then be placed into the end host
X
with the keys
H(X)
and
H(Y)
closest to
each other.
Figure 1.12 shows a simple example of DHT-based protocol. There are four
computers (i.e., A, B, C, and D) interconnected to each other based on DHT-
based protocol. Each computer can send a message to a hash function to get
a key (e.g., host A has the key numbered 507). Different content objects can
Host A
Key = 507
Host B
Key = 516
507
Communication
theory
515
Information
theory
508
Stochastic
processes
517
Statistical language
processing
Host D
Key = 540
Host C
Key = 523
540
524
Wavelets
VLSI testing
544
Advanced robot
manipulation
Figure 1.12
A simple example of a DHT-based concept.
