Network Address Translation (NAT)

Peer-to-Peer Networks and NAT

Before the expansion of cloud-computing, several peer-to-peer systems were created that enabled small groups of users to connect directly with each other. The main benefit of P2P systems is that they could be set up quickly at relatively low cost. Today, most of the remaining P2P networks are based on desktop sharing tools. Tthe host installs the software and shares the desktop with remote viewers. Those users can connect through a Web site and see the software and watch as the user steps through applications. The applications and work take place only on the host computer. Essentially, copies of the screen are transmitted to the viewers. The host often pays a fee to the remote sharing company, typically based on the number of users. The technique is useful for demonstrating desktop-based software or for walking users through a complex set of steps. But it can also be used for simple presentations by sharing slide shows or other documents.

One of the challenges with P2P groupware is that network address translation (NAT) makes it challenging to find and connect to other computers. Most companies use NAT in their routers to isolate their internal networks from the Internet—partly to improve security and partly to conserve the limited number of IPv4 addresses. In summary, each computer within the company’s network receives a unique IP address that cannot be accessed by anyone outside the company. Although security officers like NAT, it makes it considerably more difficult to establish computer connections to individuals outside the company—including traveling employees, customers, and business partners.