400电话的呼叫队列震铃方式是什么？

　　What is the ringing method for the call queue of 400 phones

　　A 400 phone can be bound to many numbers, which are bound to the management backend. In the management backend, you can set three different strategies for these bound numbers:

　　1. Ring sequentially, with customizable time intervals. When the first bound phone is not answered or busy, the first bound phone is called in sequence;

　　2. Randomly select a phone ringer from the bound phones, and if the line is busy, randomly call another bound phone;

　　3. The bound phone rings simultaneously until one of the phones picks up the call.