ABSTRACT
The 32-bit IPv4 address space, completely allocated, was the initial motivation for IPv6. It is the vanguard for network and mobile users using both data and voice by extending an IP address to 128 bits. IPv6 and IPv4 are completely separate protocols, and IPv6 is not backward compatible with IPv4. Thus networks running one of the versions will not communicate with the other directly. As devices need to support the same standard to communicate, it is expected that bridging mechanisms will evolve to interoperate between IPv4 and IPv6. As a consequence, networks would need to run a parallel infrastructure housing both protocols. The operational burden imposed by this complicated deployment is one of the factors slowing the adoption of IPv6.
