"This Technical Report provides information on the traffic availability performance of trunk-type switched exchange-access transmission paths between an Exchange Carrier's (EC) end offices and an Interexchange Carrier's (IC) point of termination (POT). Both originating access segments (from the EC to the IC) and terminating access segments (from the IC to the EC) are covered and are both referred to herein by the term access arrangement (see Figure 1). This Technical Report also provides methodologies for: a) assessing traffic availability; b) exchanging trunk forecasting information; c) trunk servicing activities; and d) reporting of results. Purpose This Technical Report is intended for use by the telecommunications industry to aid in the understanding of traffic performance and related activities. The use of this Technical Report and other Technical Reports or standards helps to assure and maintain the quality of the exchange-access service; aids the industry in planning and provisioning the exchange-access network; and defines the levels of availability that will provide end-users with quality exchange access service. This Technical Report is the product of a number of considerations. Among them are: End-user concerns Network architectures Technical capabilities of the network Network hardware and software Highly varying traffic loads among ICs Non-systematic changes in individual IC traffic growth levels Regulatory constraints and access tariff considerations Operational and economic concerns Application This Technical Report applies specifically to trunk-type switched exchange access service provided by a single EC to an IC between the EC end office and the IC POT. Switched exchange-access service is an element of voicegrade service similar to what has historically been referred to as the ""Public Switched Telephone Network."" This Technical Report applies only to access arrangements utilizing hierarchial routing and traditional network traffic measurement techniques (UPCO). Technological development/deployment may affect these traditional measurements and are for further study. For example@ look-ahead routing may require new analysis methodologies."