The present invention improves probability of success in connection by enabling
effective re-calling even for such a partner apparatus, exchanger, or network that
takes a long time in releasing processing when a connection protocol fails at calling
in G4, the line is disconnected and re-calling is performed in G3 (fall-back).
A fall-back wait timer is provided for waiting for a predetermined time before
re-calling is performed by the fall-back function. With this, at the time of fall-back,
next communication can be activated in a sufficient time. Therefore, effective
re-calling is possible even for such a partner apparatus, exchanger, or network
that takes a long time in releasing processing, whereby the probability of success
in connection is improved.
