How to solve the serious delay after the mobile phone passes through the switch?

Hello, landlord: If the computer duty mode is turned on, there will be a delay in ringing. If you want to change this delayed ringing mode, you can only change the external line of 30 B+D. Of course, your switch is analog, and you will not experience the instant communication effect of digital external line. Maybe it's normal to hear two beeps after the phone is connected. Not all telephone exchanges ring as long as you get through, so you must have passed the telephone exchange!