As the central public IPv4 address pool has already been exhausted, the deployment of IPv6 has become inevitable. However, the users still require IPv4 Internet access due to some IPv4-only applications. The IPv4aaS (IPv4-as-a-Service) IPv6 transition technologies facilitate that ISPs provide IPv4 service to their customers while using only IPv6 in their access and core networks. This paper discusses the widely used IPv4aaS IPv6 transition technologies in ISP/enterprise networks; we explain their operations, advantages, properties and consider their performances. There are currently many IPv6 transition technologies, nevertheless, in this paper, the five most prominent IPv4aaS IPv6 transition technologies are discussed, namely 464XLAT, Dual-Stack Lite, Lightweight 4over6, MAP-E, and MAP-T. Moreover, the deployment and implementations of these technologies are being analysed and inspected. This paper also overviews the benchmarking methodology for IPv6 transition technologies and surveys several papers that investigated metrics and tools utilized in analysing the performance of different IPv6 transition technologies.