Patent ID: 7457278

Claim:
A terminal connection device that is connectable to a packet network for transmitting and receiving packet data, a public switched telephone network for transmitting and receiving voice band signals, and a communication terminal for sending a connection request which contains a telephone number of a destination, said terminal connection device comprising: a connection processing unit configured to send said connection request to one of said packet network and said public switched telephone network on the basis of the telephone number of said destination contained in the connection request; a packet network state judgment unit configured to judge whether or not a communication is viable through said packet network; and a storage unit configured to store information about telephone numbers of destinations to which communication is only established through the public switched telephone network as a PSTN route-around table, wherein said connection processing unit is configured to compare the telephone numbers as in the connection request with the PSTN route-around table stored in the storage unit before a judgment by said packet network state judgment unit, if the telephone number matches one of the telephone numbers in the PSTN route-around table, the connection processing unit sends the connection request to said public switched telephone network, if the telephone number does not match any of telephone numbers as listed in said PSTN route-around table and said packet network state judgment unit judges that a communication is not viable through said packet network, said connection processing unit sends said connection request to said public switched telephone network even if it is decided to send said connection request to said packet network, and if the telephone number does not match any of telephone numbers as listed in the PSTN route-around table and said packet network state judgment unit judges that a communication is viable through said packet network, said connection processing unit sends said connection request to said packet network.