Patent attributes
To allow a call received from an accommodated device to arrive at the other party by diverting the call from an IP network to a detour network even with different numbering systems between communications over the IP network and over the detour network. A VoIP gateway apparatus 1 includes an ISDN terminal side IF portion 101, an IP network side IF portion 102, an ISDN network side IF portion 103, a condition storage portion 109, a detour determining portion 108, and a number editing portion 106. The detour determining portion 108 determines whether a call arriving at the ISDN terminal side IF portion 101 satisfies a detour condition stored in the condition storage portion 109 or not. If so, the number editing portion 106 edits the called party number of the call under a number editing condition stored in the condition storage portion 109 and then transmits it from the ISDN network side IF portion 103. If not, the call is transmitted from the IP network side IF portion 102 without editing the called party number.