Network facsimile apparatus, facsimile communication system, and method that can efficiently transport packets

A network facsimile apparatus conforms to ITU-T Recommendation T.38 Standard and includes a function of transporting packet data by using one of TCP and UDP. A packet delay detection part detects a delay in packet transmission. A UDP/TCP selection part transports a succeeding packet of an address by using UDP in a case where the delay in a preceding packet of the same address is equal to or greater than a predetermined value when transporting the packet data by using TCP, and transports a succeeding packet of an address by using TCP in a case where the delay in a preceding packet of the same address is less than the predetermined value when transporting the packet data by using UDP.