Exhaustion of IPv4 address space is highly aware for most internet players, not only Internet Service Providers (ISPs), but also Telco and Content Providers. A number of IPv4/IPv6 migration/transition tools and mechanisms have been proposed, deployed/implemented world-wide. To make IPv4 networks be able to connect to IPv6 world, 4over6, DS-lite, and 4rd seems to be the most attractive solution according to their features and functions benefits. Beside such benefits, in this paper, we investigate their performance in terms of delay time, and reliability in both inter and intra-communications. Comparison results and analysis of these 3 solutions will be given. We conclude that these figures will provide the factors of scalability and quality-of-service (QoS).