This Technical Report contains a service description of the Emergency Telecommunications Service (ETS). ETS is intended for use in a variety of networks and provides priority call/session setup capabilities that are used to support emergency response/recovery activities and disaster responders. ETS provides priority connectivity for any authorized user from any orginating point in the public network and to any destination point in the public network. It includes support of priority connectivity and communications across mutiple networks types (e.g., circuit-switched networks, wireless network/mobile radio access, cable satellite, or packet-based multi-media networks). ETS provides priority handling for all access types, network call setup, and delivery of the call, including priority handling of all associated signaling generated in conjunction with an ETS call (including queires and corresponding responses). This Technical Report includes an overview of ETS, descriptions of ETS from the end user perspective and in various types of networks. Information flows are included describing the access, intranetwork signaling, and internetwork signaling. A high-level description and security aspects of ETS is also included.