a call request control device , which in an offhook state , upon detecting a key input , checks the type of the key that was input . when the input key is a transmission / redial key , a determination is made of whether dial data is stored in the dial buffer . if dial data is stored in the dial buffer , then the dial data is set as a call destination number , and a call request message is sent . if dial data is not stored , then redial data is set as the call destination number , and a call request message is sent . telephone sets incorporating such call request control device have enhanced functionality without corresponding increase in the number of keys .