Method for switching communication modes and exchange therefor

A method for switching communication modes for shifting an exchange from a frame relay exchange having a packet exchange processing unit to an ATM exchange in a communication system having a plurality of exchanges each accommodating a plurality of terminals and including a frame relay exchange having a packet exchange processing unit and having a network for connecting the plurality of exchanges to each other in order to transfer data among said plurality of terminals, comprising

• a first step of selecting any one exchange among said plurality of exchanges,
• a second step of operating said selected exchange as a frame/cell compatible type exchange capable of operating for both outputting input frame relay signals for said frame relay exchange as ATM cell signals and outputting input ATM cell signals as frame relay signals for said frame relay exchange, reversibly, and
• a third step of executing said first step and second step for an exchange which has not yet been selected and
• repeating said third step to autonomously shift all said exchanges to said ATM exchanges,
• wherein, in said second step,
• whether an opposing exchange or an opposing terminal of another party of communication operates for frames or operates for cells is automatically identified in said selected exchange, and
• the selected exchange is operated as an exchange operating for frames or an exchange operating for cells according to the result of the identification.

An exchange used in a communication system having a plurality of exchanges each accommodating a plurality of terminals and including a frame relay exchange having a packet exchange processing unit, and having a network for connecting the plurality of the exchanges to each other in order to transfer data among said plurality of terminals, said exchange comprising:

• an ATM side bus and a frame relay side bus provided in parallel,
• a frame/cell compatibility function unit inserted in said ATM side bus, said frame/cell compatibility function unit being capable of both outputting input frame relay signals for said frame relay exchange as ATM cell signals and outputting input ATM cell signals as frame relay signals for said frame relay exchange, reversibly, and
• a frame/cell switch unit for alternatively switching between said ATM side bus and frame relay side bus, wherein
• said frame/cell switch unit switches alternatively between said ATM side bus and frame side bus in accordance with an instruction from the outside, and
• said instruction is given according to office data registered in advance.

An exchange used in a communication system having a plurality of exchanges each accommodating a plurality of terminals and including a frame relay exchange having a packet exchange processing unit and having a network for connecting the plurality of the exchanges to each other in order to transfer data among said plurality of terminals, said exchange comprising:

• an ATM side bus and a frame relay side bus provided in parallel,
• a frame/cell compatibility function unit inserted in said ATM side bus, said frame/cell compatibility function unit being capable of both outputting input frame relay signals for said frame relay exchange as ATM cell signals and outputting input ATM cell signals as frame relay signals for said frame relay exchange, reversibly, and
• a frame/cell switch unit for alternatively switching between said ATM side bus and frame relay side bus, wherein
• said frame/cell switch unit switches alternatively between said ATM side bus and frame side bus in accordance with an instruction from the outside,
• said exchange further provided with:
• a frame/cell detection unit for detecting whether a signal input from the outside is comprised of frames or cells,
• said instruction being created in accordance with the result of detection by this frame/cell detection unit,
• a pair of said frame/cell switch units formed at the two end portions of said ATM side bus and frame side bus provided in parallel and
• a switch control unit for receiving as input the result of detection by said frame/cell detection unit and controlling said pair of interlocked frame/cell switch units.