Communication apparatus connected to ISDN

A communication apparatus connected to an integrated service digital network having a first information channel, a second information channel, and a control channel, and having a first communication function and a second communication function, comprising:

• first communication means for performing communication with another party's communication apparatus by said first communication function using said first information channel;
• memory means for storing information indicative of a number for discriminating another party's communication apparatus when a call is received or a call is made by the first communication means;
• detecting means for detecting a call request by said second communication function during communication by the first communication means;
• call means for making a call, based on said information stored in said memory means, when a call request is detected by the detecting means;
• and
• selecting means for selecting either a first mode, in which a call is possible using said call means or a second mode, in which a call is not possible using said call means;
• wherein said call means makes a call, based on said information stored in said memory means, when said selecting means selects the first mode.

A communication apparatus connected to one subscriber's line of an integrated service digital network having a first information channel, a second information channel, and a control channel, and having a first communication function and a second communication function, comprising:

• a handset;
• first communication means for performing communication with another party's communication apparatus by said first communication function using said first information channel;
• memory means for storing information indicative of a number for discriminating another party's communication apparatus when a call is received or a call is made by the first communication means;
• detecting means for detecting a call request when said handset has been taken off a hook during communication by the first communication means;
• call means for making a call by reading said information stored in said memory means using said control channel, when a call request is detected by the detecting means;
• and
• second communication means for performing a communication with said another party's communication apparatus by said second communication function using said second information channel, after the call by the call means.

A communication apparatus connected one subscriber's line of an integrated service digital network having a first information channel, a second information channel, and control channel, and having a first communication function and a second communication function, comprising:

• a communication start switch;
• first communication means for performing communication with another party's cmmunication apparatus by said first communication function using said first information channel;
• memory means for storing information indicative of a number of discriminating another party's communication apparatus when a call is received or a call is made by the first communication means;
• detecting means for detecting a call request by depression of said communication start switch during communication by the first communication means;
• call means for making a call by reading said information stored in said memory means using said control channel, when a call request is detected by the detecting means;
• and
• second communication means for performing a communication with said another party's communication apparatus by said second communication function using said second information channel, after the call by the call means.