Patent ID: 6496576
Filing Date: 2002-12-17
Classification: H04M,H04Q

Abstract:
A digital key telephone system having a main unit connected to a communication network through an office line and accommodating a plurality of extension lines connected to extension terminals, and having a function of switching and connecting the office line to at least one of the plurality of extension lines and/or the extension lines to each other, comprising:camp-on control means for, when a new call arrives at an extension line which is communicating, holding said new call; line determination means for determining whether said new call is on the office line or one of the plurality of extension lines; and selective generation means for, during a period in which the new call is held by said camp-on control means, causing the called extension line to selectively generate a first camp-on tone indicating that the new call is on the office line or a second camp-on tone indicating that the new call is on one of the plurality of extension lines in accordance with a result of the determination made by said line determination means.