Provided are a method, system, and program for managing a network providing Input/Output (I/O) paths between a plurality of host systems and storage volumes in storage systems. An application service connection definition is provided for each connection from a host to a storage volume. At least one service level guarantee definition is provided indicating performance criteria to satisfy service requirements included in at least one service level agreement with at least one customer for network resources. Each service level guarantee definition is associated with at least one application service connection definition. Monitoring is performed as to whether Input/Output (I/O) requests transmitted through the multiple I/O paths satisfy performance criteria indicated in the service level guarantee definition associated with the I/O paths.