An examination of IPv4 and IPv6 networks : Constraints and various transition mechanisms

The concept of transiting from IPv4 network to IPv6 network is being processed vigorously. Extensive study is being done presently on this subject as transition from IPv4 to IPv6 requires a high level compatibility and clear procedure for easy and independent deployment of IPv6. The transition between IPv4 internet and IPv6 will be a long process as they are two completely separate protocols. IPv6 is not backward compatible with IPv4, and IPv4 hosts and routers will not be able to deal directly with IPv6 traffic and vice-versa. In fact that there will be extreme difficulties with address allocation and routing if the internet is to continue to run indefinitely using IPv4. Also it is impossible to switch the entire internet over to IPv6 over night. As IPv4 and IPv6 will co-exist for a long time, this requires the transition and inter-operation mechanism. Due to this reason several transitions mechanisms have been developed that can be used to make the transition to IPv6 smoothly. Most applications today support IPv4 and thus there is a need to run these applications on IPv6 access network, especially to persons who are generally on mobile and they want to securely connect to their home network so as to reach IPv4 services. This paper discusses constraints, various techniques and standards require for high level compatibility smooth transition and interoperation between IPv4 and IPv6 by removing the constraints.