An electronic device connected to a first communication network is provided. The electronic device may include: a communication module comprising communication circuitry; a processor operatively connected to the communication module; and a memory operatively connected to the processor, wherein the memory may store instructions that, when executed, cause the processor to control the electronic device to: transmit a message requesting a call connection through a first transmission protocol to an external electronic device using the communication module; receive a provisional response message for the request through the first transmission protocol from the external electronic device using the communication module; connect to a second communication network using the communication module based on the call connection not being supported by the first communication network; transmit a response message for the received provisional response message through a second transmission protocol to the external electronic device using the communication module; and perform the call connection using the connected second communication network.