Mobile network operators are deploying IPv6 to their
mobile networks in recent years, to support ever increasing
mobile and IoT devices. They also adopt IPv4-IPv6 transition
techniques to provide connectivity from their IPv6 networks to
IPv4 networks. Since IPv6 deployment to mobile network is still
in an early stage, the performance assessment on IPv6 based
mobile network is needed, regarding both IPv6 and IPv4. In
this paper, we focus on assessing the performance of IPv6 based
mobile networks. We first analyze the detailed TCP connection
procedures in accordance with the different IP versions that
the end hosts use. Based on the analysis result, we suggest
improvement points to speed up the connection establishment. We
also compare the performance difference between IPv6 and IPv4
by measuring the connection establishment time to 40 popular
dual-stack websites. We witnessed that IPv4 can be connected
faster than IPv6 in most cases because of the immaturity of the
IPv6 infrastructure.