Introduction to Peer-to-Peer Networks

Peer-to-peer networking is an approach to computer networking in which all computers share equivalent responsibility for processing data. Peer-to-peer networking (also known as peer networking) differs from client-server networking, where specific devices have responsibility for providing or serving data, and other devices consume or otherwise act as clients of those servers.

Characteristics of a Peer Network

Peer-to-peer networking is common on small local area networks (LANs), particularly home networks. Both wired and wireless home networks can be configured as peer-to-peer environments.

Computers in a peer-to-peer network run the same networking protocols and software. Peer network devices are often situated physically near one another, typically in homes, small businesses, and schools. Some peer networks, however, use the internet and are geographically dispersed worldwide.

Home networks that use broadband routers are hybrid peer-to-peer and client-server environments. The router provides centralized internet connection sharing, but file, printer, and other resource sharing are managed directly between the local computers involved.

Peer-to-Peer and P2P Networks

Internet-based peer-to-peer networks became popular in the 1990s due to the development of P2P file-sharing networks such as Napster. Technically, many P2P networks are not pure peer networks but rather hybrid designs as they use central servers for some functions such as search.

Peer-to-Peer and Ad-Hoc Wi-Fi Networks

Wi-Fi (wireless) networks support ad-hoc connections between devices. Ad-hoc Wi-Fi networks are pure peer-to-peer compared to those that use wireless routers as an intermediate device. Devices that form ad-hoc networks require no infrastructure to communicate.

Benefits of a Peer-to-Peer Network

P2P networks are robust. If one attached device goes down, the network continues. In client-server networks, when the server goes down, it takes the entire network with it.

Computers in peer-to-peer workgroups can be configured to allow sharing of files, printers, and other resources across all devices. Peer networks allow data to be shared in both directions, whether for downloads to a computer or uploads from a computer.

On the internet, peer-to-peer networks handle a high volume of file-sharing traffic by distributing the load across many computers. Because they do not rely exclusively on central servers, P2P networks scale better and are more resilient than client-server networks in case of failures or traffic bottlenecks.

Peer-to-peer networks are relatively easy to expand. As the number of devices in the network increases, the power of the P2P network increases, as each additional computer is available for processing data.

Security Concerns

Like client-server networks, peer-to-peer networks are vulnerable to security attacks.

• Because each device participates in routing traffic through the network, hackers can easily launch denial of service attacks.
• P2P software acts as server and client, which makes peer-to-peer networks more vulnerable to remote attacks than client-server networks.
• Data that is corrupt can be shared on P2P networks by modifying files that are on the network to introduce malicious code.