Date Added: Oct 2010
The Internet has evolved from its original design. The user cares about what they are looking for, not which machine provides the data or the service. The host-to-host Internet tends to become a data-oriented network. In the pressures of commerce and security, the middle-boxes, such as Network Address Translators (NATs), firewalls and caching servers, become commonplace in current Internet. They improve the performance of the applications and security, but also violate the Internet layering and are difficult to maintain and configure.