loying IPv6 in 3GPP Networks volumes can guarantee that scalability issues are found. On the other hand, opening the service to too large a group too fast may be problematic. It may be difficult to roll back once millions of phones have been provisioned, and the customer support hotlines are congested. Participate in network operator groups and other conferences where operators share their experiences. This may help avoiding some of the potholes other people have already found. In addition, sharing one's own experiences also helps finding solutions to common problems, and also helps the vendors to enhance their products. The transition to IPv6 is an industry-wide project. It makes good business sense to participate in that. Try it out! There is no substitute for hands-on experience. Only trying it out will provide the experience and knowledge on what can go wrong and what works well. It is best to find the problems as early as possible rather than after the commercial launch. Start now! Unless the planning and transitioning has not even been started yet, it is time to start now. The only thing that can be assured for the transition journey is that it is going to be difficult, and issues about the network will be discovered that will need some problem solving. The earlier they can be found, the quicker solving of the problems can be started, and therefore, there is more time to solve them. It is difficult to fix problems, but it is definitely not nice to have to fix them in a hurry! As stated earlier, this is an overview at best. However, we hope that we can import some structure to the transition process, and perhaps help the transition process. The most important part is to start the enabling of IPv6 as a service. The other steps will follow naturally. 5.7 Chapter Summary In this chapter we looked into IPv6 transition in 3GPP networks and into a selected set of IPv6 transition mechanisms. We boldly chose the IPv6 transition mechanism for a closer inspection that we find fitting into wireless 3GPP architecture en