本文档提供了交换运营商终端办公室和交换运营商间终端之间中继型交换接入传输路径的流量可用性性能信息。更具体地说，它包括关于设计阻塞目标的信息；交通相关数据的报告；评估阻塞结果；干线群服务；并提供干线预测数据。

This document provides information on the traffic availability performance of trunk-type switched exchange-access transmission paths between an Exchange Carrier's end office and an Inter-exchange Carrier's point of termination. More specifically, it includes information regarding design blocking objectives; reporting of traffic-related data; assessing blocking results; trunk group servicing; and providing trunk forecasting data.