As the Internet Assigned Numbers Authority (IANA)
delegated the last five “/8” IPv4 address blocks to the
Regional Internet Registries in 2011 [1], and the depletion of
the IPv4 address pool of the RIPE NCC (which is responsible
for the IPv4 address allocations in Europe) is expected to
happen in 2012 [2], the deployment of the IPv6 became
inevitable in Europe, too. Internet service providers (ISPs)
must urgently take preparations for both providing IPv6
services and the co-existence of the two versions of IP. (Of
course, not only ISPs, but also customers (including both
private and business customers) have to manage this complex
change carefully [10]; and because of its complexity they have
to use some integrated approach for the evaluation of all
aspects concerning their activities and networks [11].)