Call Via Work in Skype for Business Server 2015

What is Call Via Work 

Call Via Work is a new feature in SfB Server which enables you to integrate your SfB solution with your existing PBX phone systems. A user enabled for Call Via Work can click in SfB to call another user, either within your organization or an external user. The call is completed using the user's PBX phone. This enables a user with a PBX phone to include rich audio in their SfB conversations. 

How it works 

It uses Unified Communications Web API (UCWA) as the agent between the PBX system and SfB server, so that no special gateway is needed to connect SfB with your PBX system. 

Workflow 

1. The user selects a user in their Skype for Business client, and clicks the phone icon to call them. Or, during an IM conversation, the user clicks to call the user they are having the session with. 
2. The PBX phone of the user who placed the call starts to ring. The caller ID for this phone shows a global phone number which you have set up to show in the caller ID of all users placing Call Via Work calls. This global phone number is not an actual phone number that corresponds to any one person's phone. Instead, it is a visual signal to let a user know that this is their own outgoing call, and not an incoming call happening at the same time. When you deploy Call Via Work, you should educate those users about this global phone number and what it means. 
3. The user who placed the call picks up their PBX phone. Skype for Business then initiates the voice call to the callee.
4. When the callee answers, the voice call begins. If the two users already had an IM session going, it can continue. 

Joining a conference with Call Via Work 

A Call Via Work user can join a scheduled meeting by clicking the meeting URL. Skype for Business then shows a Dialing out to message until the meeting service dials the user's PBX phone. The Call Via Work user then picks up the PBX phone and joins the meeting. 

A Call Via Work user can also use the Meet Now option in Skype for Business to create Meet Now meetings. The user then sees the Dialing out to message, and the PBX phone rings. 

A Call Via Work user can also dial in to a meeting by calling the Conference Bridge number from within Skype for Business. If a conference PIN is required, the user must use their PBX phone to input the PIN. 

Incoming Calls 

When a user enabled for Call Via Work receives a Skype for Business call, the PBX phone and the user's Skype for Business clients all ring simultaneously (if the user has set up simultaneous ring). The user can accept the call either by picking up the PBX phone or clicking Accept on the Skype for Business notification. If the user accepts the call using Skype for Business, the Skype for Business window for the call stays open. But if the user accepts the call by picking up the PBX phone, then the Skype for Business notification window closes and there is no Skype for Business session, only the voice call over the PBX phone. 

Note: 

When a user enabled for Call Via Work receives a PBX call, only the PBX phone rings.