What is Peer to peer (P2P)

What is Peer Computing?

Hailed by some as a potentially revolutionary phenomenon and by others as yet another fad in Internet technology, peer computing, also called peer-to-peer or P2P, is something you'll be hearing a lot about. So what is it? Are there peer applications for business and personal use that go beyond file sharing and searching? Will peer computing become the next generation of computing? This short article explains.

Innovation at the Edge of the Network

Centralized Web computing has proven itself effective for information broadcast and electronic commerce over the Internet and on corporate intranets. Peer computing, on the other hand, makes efficient use of computing and communications resources around the "edge" of the network. How? Some peer apps gain efficiencies by aggregating the distributed storage capacity (e.g., Napster, gnutella) and computing cycles (e.g., SETI@home) of devices spread across a network, others, such as instant messaging, take advantage of the direct network connections that peer devices can make to enhance the effectiveness of communications.

The most familiar example of a peer device is the telephone. Voice connections over the telephone are made directly, from one point on a network to another. The critical distinction between the phone network and peer computing is that the phone employs an intelligent network (with built-in logic for routing, tracking and billing) with relatively "dumb" devices (telephone handsets) at the edge of the network, while the peer-to-peer Internet model uses a relatively "dumb" network (the Internet) with no built-in application logic and high function endpoints (i.e., computers).

High function at the edge of the network means there's far greater potential for rapid innovation in Internet peer services, tools and applications.

Peer Communications

Why should a business with an existing Web-based messaging system consider developing and deploying peer group communications applications? The answer is that while the Web can adequately serve as a communications platform, peer computing simply may be more cost-effective, more personally efficient and more flexible and adaptable to person-to-person communication.

Peer Communications are Cost Effective

There is no need for IT administrators to manage access, security, storage or other tasks associated with centralized Web-based shared work spaces. Team members make use of their own local computing resources.
Consider the inefficiency of sending an email with a file attachment to ten recipients, who then reply to all with the file still attached, taxing network and storage resources. Peer-to-peer file transfer can minimize network traffic while eliminating redundant storage.
Administrative costs are not limited to activities inside the firewall. Peer computing makes direct use of local computing resources in business-to-business and business-to-consumer settings.
Peer communications offer personal efficiency

In a peer computing environment, as in a person-to-person phone call, the user has personal control. He or she makes a direct connection to someone else, there's no up-front setup required. What's more, with most peer communications, the user easily can bring additional members into the interaction.

Peer communications offer flexibility and adaptability

This sense of personal control will grow as further innovation occurs at the edge of the network. Why rely on a development team to add server functionality for a shared application, such as a Web-based shared work space, when it can be added directly (and more quickly) at the edge of the network by an end user?

Is There a Future for Peer Computing?

If stand-alone peer computing tools such as Napster and gnutella are the 'thin edge of the wedge' opening up a new dimension of computing, then we can expect the next phase of this trend to unveil a general purpose platform - like the PC or the Web server - on which a variety of applications can be built and deployed. Beyond that stage, we can expect IT management and systems integrators to tie these new peer applications together with existing systems....

Clay Shirky is a Partner at The Accelerator Group. He writes extensively about the social and economic effects of the internet for the O'Reilly Network