In both IPv4 and IPv6, IP address is assigned to interface and shared by different users on a same host. This model of addressing is not suitable for future Internet-based computing, where user-oriented accounting, behavior tracing, multi-homing and independent port usage must be supported. Because IPv6 provides a big enough space that everyone in the world can own several addresses, it is believed that a new, user-oriented IP addressing model will appear in the near future.

On the other hand, network protocol stacks in current operating systems are designed in the framework of interface-oriented addressing model. To specify a dedicated address to each individual user, the kernel must be modified so that one user can use only its own IP address, either for source or destination of a packet. Secondly, both user and IP address administration tools must contain a map from user ID to a group of address that the user having permission to apply them. Furthermore, the behavior of application programming interface must be modified in order that each user-mode network program binds address properly. Issues of compatibility and security are also discussed.