Communication terminal equipment

Claim 1

Communication terminal equipment which is connected to an ISDN (integrated services digital network) to perform two-way communications with terminal equipment on a complex communications network having an ISDN interconnected with existing communication networks, comprising: a calling means for calling a receiver terminal according to a call control procedure and under the condition of communications that comply with a specific calling condition; a call control procedure changing means for changing the call control procedure upon detecting a switch from one communications network to another to be handled; a disconnect information detecting means for detecting the disconnect information being sent back when a communication trouble has occurred; a repeated call management table storage means for registering a plurality of repeated call management tables each specifying the relationship between disconnect information and the condition of making a repeated call; a repeated call management table selecting means by which a repeated call management table that complies with said control procedure is selected from said repeated call management table storage means; a repeated calling condition selector means by which an appropriate condition for making the repeated call is selected from said selected repeated call management table on the basis of the returned disconnect information; and a repeated calling means for calling again the receiver terminal of interest by the call control procedure and under the condition of communications that comply with the selected condition for making the repeated call.