Next Generation Internet and IPv6
Currently, two versions of the Internet Protocol are in use, IPv4 and IPv6 (Internet Protocol version 4 and 6) as addressing system of the Internet. IPv4 was designed to support up to 4.3 billion (4.3 x 109) Internet hosts. However, the exponential growth of the Internet has led to IPv4 address exhaustion. The Internet Assigned Number Authority (IANA) pool of unallocated IPv4 Internet addresses was completely exhausted on 3rd February 2011 and the Regional Internet Registries (RIRs) unallocated IPv4 address pool exhaustion date is predicted to happen a month or two on either side of 1st July 2011. It is a matter of time before the RIRs and ISPs will be unable to grant any requests for new IPv4 addresses. The successor Internet addressing scheme IPv6, developed in the mid 1990s, is being deployed actively worldwide.
Key IPv6 features include: Expanded addressing to improve scalability, hierarchical routing facilitating route aggregation, enhanced performance and extensibility through more efficient routing made possible through simplified and extension headers respectively, QoS support for Multimedia services, built-in and mandatory authentication and encryption for better security, auto-configuration of IP enabled devices for plug-and-play and mobility through Mobile IPv6 support that eliminates the complexity of triangular routing of Mobile IPv4.