Networks are the need of this age and several types of networks are available with different advantages, working and limitations. This book is designed with the purpose to present the overview of connectionless network, and explain the working, advantages and limitations of connection-oriented networks at one spot. The author has explained the structure of end-to-end WAN connections, which is divided into two stages: first, the WAN access technologies used in the local loop (last mile) and secondly, the cloud-based packet-switched network which can be virtual-circuit-networks (connection-oriented) or datagram/internet (connectionless). These WAN protocols or technologies include Transmission Control Protocol/Internet Protocol (TCP/IP), X.25, Switched Multimegabit Data Service (SMDS), Frame relay, Asynchronous Transfer Mode (ATM), Tag Switching, Multiprotocol Label Switching (MPLS), Software Defined Networking (SDN), and Segment Routing (SR). Moreover, this survey introduces a newprotocol called Route Once and Cross-Connect Many (ROACM), which is a new protocol in the WAN networking and protocol along with the future of packet switching networks.