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, e