This paper develops a connection establishment framework for protecting connections against single-link failures using link protection at the granularity of a connection, referred to as Connection Switched Link Protection (CSLP). As a connection is routed only around a failed link, the channel assignment for the connection on the backup path of the failed link must be consistent with that of the primary path. Such a consistency is guaranteed at the time of call admission. The advantages of employing link protection at the connection level is established by comparing its performance through extensive simulations against link protection at the granularity of a fiber, referred to as Fiber Switched Link Protection (FSLP). Link protection at the connection level is shown to significantly outperform that at the granularity of a fiber, specifically when some traffic requires protection while others do not.