in the 1990s using dial-up modems over their telephone lines, that is, over the established global telecommunication infras- tructure for telephony. Also, the Ethernet access networks were interconnected via the global telecommunication infrastructure created for transmission primarily of digital telephony, based on 64 kbit/s dedicated bitrate in each direction of the voice communi- cation (i.e. ITU-T G.711 voice codec standard, based on pulse code modulation (PCM)). The "chunk" bitrate of 64 kbit/s was the basis for all digital telecommunication systems in the 1990s, and even in the 2000s. For example, the main transport technology in digital PSTNs (public switched telephone networks), the SDH (synchronous digital hierarchy) was based on the 64 kbit/s chunks made for voice, SO the STM-1 (synchronous transport module, level 1) has a bitrate of 155.52 Mbit/s, which equals exactly 2430 X 64 kbit/s, and higher transport modules, STM-N, have bitrates of N X 155.52 Mbit/s, which again is a multiple of 64 kbit/s as basic voice throughput in one direction (from user A to user B) in digital telephony. However, the appearance of the Internet on the global ICT scene in the 1990s (sped up by the invention of the World Wide Web and its growth in that period) resulted finally in transport of Internet traffic (various data carried with IP packets and transported by using the IP stack end-to-end) over such SDH transport networks cre- ated for transport of digital voice signals. With the convergence of ICTs to the Internet networking principle, Internet networking principles started to penetrate from access 1.2 Convergence of the Telecom and Internet Worlds and QoS networks (e.g. Ethernet) to metro and transport networks, thus making SDH and other technologies from the digital PSTN era obsolete. What did this convergence of the telecom and Internet worlds mean? Instead of having separate networks for transmission of different services (e.g. a telephone network for telephony, broadcast network for television, and separate network