How to Make an external phone call and an external phone call

How to Make an external phone call and an external phone call

After using a telephone switch, when using a telephone switch, you usually need to dial a "0" before dialing the phone number.

For some old-fashioned programmable telephone switches that are somewhat backward behind, it is recommended that the phone numbers be dialed after 0 intervals of about 1-2 seconds. Otherwise, the phone numbers may occasionally fail to be called or are not reflected after the phone number is pressed.

Some switches may also be set to outgoing numbers such as 4, 6, and 9 in addition to 0.

After the outbound number is entered, the system prompts a busy voice or no sound, or "excessive permission". This means that the external line is being occupied by another person, or the extension lock is used, or the extension is subject to the outbound call level controlled by the switchboard. This is basically the way for an internal phone to call an external line! Individual models are not described in detail.