A telecommunication control system, in a telecommunication network having one, two or more telecommunication control systems for performing a call control between terminals and enabling telecommunication between a caller terminal and a receiver terminal by an intercommunication between a caller side telecommunication control system of the one for communicating with the caller terminal and a receiver side telecommunication control system of the one for communicating with the receiver terminal, characterised by comprising: a caller priority call category judgment unit for generating a first priority call category identifier by judging a priority call category from a combination of a requested call category and terminal capability information included in first connection configuration information notified by the caller terminal; a priority call category identifier notification unit for notifying the receiver side telecommunication control system of the first priority call category identifier; a requested call category judgment unit for judging a requested call category to be requested to the receiver terminal from a first priority call category identifier notified by the priority call category identifier notification unit; a requested call category notification unit for notifying the receiver terminal of the requested call category; a receiver priority call category judgment unit for generating a second priority call category identifier by judging a priority call category from a combination of a response call category and terminal capability information included in second connection configuration information notified by the receiver terminal; a connection call category judgment unit for judging a connection call category from the first priority call category identifier and second priority call category identifier; and a telecommunication establishment unit for making telecommunication between the caller terminal and receiver terminal established by a connection call category judged by the connection call category judgment unit. a caller priority call category judgment unit for generating a first priority call category identifier by judging a priority call category from a combination of a requested call category and terminal capability information included in first connection configuration information notified by the caller terminal; a priority call category identifier notification unit for notifying the receiver side telecommunication control system of the first priority call category identifier; a requested call category judgment unit for judging a requested call category to be requested to the receiver terminal from a first priority call category identifier notified by the priority call category identifier notification unit; a requested call category notification unit for notifying the receiver terminal of the requested call category; a receiver priority call category judgment unit for generating a second priority call category identifier by judging a priority call category from a combination of a response call category and terminal capability information included in second connection configuration information notified by the receiver terminal; a connection call category judgment unit for judging a connection call category from the first priority call category identifier and second priority call category identifier; and a telecommunication establishment unit for making telecommunication between the caller terminal and receiver terminal established by a connection call category judged by the connection call category judgment unit.