If the other party doesn't answer the phone or return the message, the line is busy.

There is no answer when the line is busy, which may be the following three situations:

1. It is very likely that the other party is on the phone and is not connected to the wireless network, so the line is busy, and the phone priority is higher than WeChat. 2. The other party is making a WeChat call. If we call at this time, it will also show that the other party is busy. 3. The network is not smooth. If the other party is not convenient to answer the phone, you can not contact him first, and he will contact you naturally when he is busy, or wait for a while and then take the initiative to contact him. If it is a particularly urgent notice or something, you can send a short message to inform.