ince DS-Lite is not even part of the recommended transition tool set for 3GPP networks, there is little hope, for example, for NAS protocol support for bootstrapping the required bootstrapping information. 6RD [5] is an automatic tunneling protocol based on 6to4. The difference from 6to4 is that instead of the 6to4 IPv6 prefix, 6RD uses the operator's own prefix. This solves many of the problems manifested in 6to4 the IPv4 address does not have to be globally unique as long it is unique in the operator's network, and the asymmetric routing issues are not present in 6RD as the routing is based on the operator's own address prefix. 6RD has been designed to be run from the customer premises equipment, such as a residential gateway or a home router. The 6RD address is created by combining the operator's IPv6 prefix with a part of the home router's IPv4 address. This creates a prefix that is equal or shorter than /64. As the used IPv4 address is configured by the operator, a similar stateless tunneling mechanism to 6to4 can be used. 6RD is an example of a transition solution that can implement a mesh topology. Interestingly, 6RD has been one of the most successful transition technologies with many large live network deployments. Its success has been on the fixed network access where CPE devices could be upgraded (or switched) to 6RD supporting firmware. There has not been a similar level of success or even interest in using 6RD on the wireless networks, because of obvious reasons discussed earlier in this chapter. Transition Scenarios for 3GPP 3GPP started the specification work on IPv6 and on the IPv6 transition at the end of 1990s. When looking at the IPv4 address exhaustion problem timeline, and the IPv6 technical maturity, 3GPP started the specification work relatively early. While starting the Deploying IPv6 in 3GPP Networks specification early is admirable, the implementation and especially deployment has lagged behind significantly. In practice, this means that the technology, network environment, and even the 