A server apparatus for establishing communication with a plurality of input/output devices via a network. The apparatus includes: a management unit configured to manage a communication session with the input/output devices; a storage unit configured to store information of the input/output devices in association with group information thereof; an execution unit configured to execute an application program; a communication unit configured to receive an operation instruction for the application program and to transmit to the input/output devices a processing result of the application program; a determination unit configured to determine whether the processing result requires connection of the input/output devices to an external server; and a message transmission unit configured to generate a message including an instruction to connect to the external server, when the determination unit determines that the processing results requires such a connection. The message includes the group information.