Communication apparatus
AssigneeCanon Kabushiki Kaisha
InventorMasahiro Odaira
Life of this patent
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Abstract
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.
Claims12
A communication apparatus connected to an ISDN which comprises:
- decision means for, when call connection fails, deciding a reason for the failure in connection;
- setting means for setting a timer value used to wait for a predetermined time after a line disconnection failure when the decision means decides a mismatch in communication mode;
- and
- control means adapted for waiting for the predetermined time in response to the decision of a mismatch in communication mode made by the decision means, and then switching the communication mode to another communication mode to try the call connection again.
A communication apparatus connected to an ISDN, having a plurality of communication protocols in a B channel, said apparatus including D-channel control means for controlling a call in a D channel, and a plurality of B-channel control means for conducting protective controls corresponding to a plurality of communication modes in the B channel, said apparatus comprising:
- decision means for, when call connection by the D-channel control means fails, deciding whether or not call connection should be tried by the D-channel control means again after switching a communication mode in the B channel to another communication mode;
- timer control means for waiting for a predetermined time after a line disconnection failure when the decision means decides that the call connection should be tried by the D-channel control means again after the switching to such another communication mode in the B channel;
- and
- control means adapted for switching to said another communication mode in the B channel after waiting for a predetermined time by the timer control means to try the call connection again by the D-channel control means.
A communication method in an ISDN, comprising the steps of:
- when call connection fails, deciding a reason for the failure in connection;
- setting a timer value used to wait for a predetermined time after a line disconnection failure when the decision step decides a mismatch in communication mode;
- and
- controlling adapted for waiting for the predetermined time in response to the decision of a mismatch in communication mode made in the decision step, and then switching the communication mode to another communication mode to try the call connection again.
A communication method in an ISDN, having a plurality of communication protocols in a B channel, said method including a D-channel control step for controlling a call in a D channel, and a B-channel control step for conducting control corresponding to each of a plurality of communication modes in the B channel, said method comprising the steps of:
- when call connection by the D-channel control step fails, deciding whether or not call connection should be tried in the D-channel control step again after switching a communication mode in the B channel to another communication mode;
- controlling a timer for waiting for a predetermined time after a line disconnection failure when the decision step decides that the call connection should be tried in the D-channel control step again after the switching to such another communication mode in the B channel;
- and
- controlling adapted for switching to said another communication mode in the B channel after waiting for a predetermined time in the timer control step to try the call connection again by the D-channel control step.
A storage medium to store a computer program for the implementation of a communication method in an ISDN, comprising the steps of:
- when call connection fails, deciding a reason for the failure in connection;
- setting a timer value used to wait for a predetermined time after a line disconnection failure when the decision step decides a mismatch in communication mode;
- and
- controlling adapted for waiting for the predetermined time in response to the decision of a mismatch in communication mode made in the decision step, and then switching the communication mode to another communication mode to try the call connection again.
A storage medium to store a computer program for the implementation of a communication method in an ISDN, having a plurality of communication protocols in a B channel, said method including a D-channel control step for controlling a call in a D channel, and a B-channel control step for conducting control corresponding to each of a plurality of communication modes in the B channel, said method comprising the steps of:
- when call connection by the D-channel control step fails, deciding whether or not call connection should be tried in the D-channel control step again after switching a communication mode in the B channel to another communication mode;
- controlling a timer for waiting for a predetermined time after a line disconnection failure when the decision step decides that the call connection should be tried in the D-channel control step again after the switching to such another communication mode in the B channel;
- and
- controlling adapted for switching to said another communication mode in the B channel after waiting for a predetermined time in the timer control step to try the call connection again by the D-channel control step.
Dependencies are inferred from the claim text.