电话呼入处理程序，实现当外线呼入时根据其所拨的分机号转入相应的分机，分机摘机，该分机拍插簧后根据提示音拨相应的分机号可转接电话，在分机占线或者尚未摘机时二次拍插簧可恢复原先与外线的通话。-Incoming call handling procedures, the time to achieve When you hear the incoming call according to its extension into the corresponding extension number, extension hook, after the extension spring shoot inserted under the appropriate tone dial extension number to transfer the phone, in the extension Busy or not the secondary hook shot with an outside plug spring restored the original call.