A call monitoring method for detecting an error in a Bearer-Independent Call Control (BICC) environment using an Internet Protocol (IP) as a bearer is provided, in which an MSC receives connection information about a called exchange from another MSC, requests IP resource allocation for configuring a termination to a Media GateWay (MGW) controlled by the MSC based on the received connection information about the called exchange, determines, upon receipt of a resource allocation failure message from the MGW, whether a cause of a resource allocation failure is an IP allocation error, and transmits the resource allocation failure message to a resource manager, if the cause of the resource allocation failure is an IP allocation error.