Call Flows

Think of a Call Flow as the "GPS route" a phone call takes from the moment someone dials a number to the moment the call is ended. In a VoIP system (like your Yealinks), this isn't just a straight line; it's a series of "if/then" decisions made by your phone system (PBX).

Here is a breakdown of how a typical business call flow works:

1. The Inbound Journey (Customer calling you)

When an outside caller dials your business number, the system follows a pre-set path:

• Step A: The Gatekeeper (IVR/Auto-Attendant): The caller hears, "Press 1 for Sales, 2 for Support." This routes the call based on the caller's input.
• Step B: The Waiting Room (Queue/Ring Group): * Ring Group: All phones in a department (e.g., Sales) ring at once. Call Queue: Callers wait in line, hearing music until an agent is free.
• Step C: The Handshake: One of your Yealink phones "answers" the INVITE packet sent by the server, and the audio path (RTP) is established.

2. The Outbound Journey (You calling a customer)

When you pick up your Yealink and dial a number:

1. Digit Map: The phone checks if the number you dialed is valid (e.g., is it 10 digits?).
2. Request: The phone sends a "SIP INVITE" to your provider (the cloud).
3. Authentication: The server checks if your phone is "Registered" (using those SIP credentials we talked about earlier).
4. Routing: The provider sends the call out to the Public Switched Telephone Network (PSTN) to reach the recipient.

3. Common Call Flow Components

To manage these flows, admins use these common "building blocks" in the interface:

Visualizing the Flow

Imagine a tree:

• The Trunk: The main business number.
• The Branches: The IVR options (Sales, Support).
• The Leaves: The individual Yealink handsets.

Fun Fact: If you ever hear "one-way audio" (you can hear them, but they can't hear you), it usually means the call flow "route" is working, but a firewall is blocking the audio "packets" from getting back to your phone.