UC-ONE Add-Ins (EOL ab 7.12.2019)

Skype4 Business Add-In für UC-Desktop Windows

S4B Add-In für UC-Desktop Communicator Windows 21.3.1


The UC-One Add-in for Microsoft Skype for Business (S4B) is a client-side add-in that enables calling a phone number using “Call from Phone” or “VoIP from S4B” through UC-Desktop.

Instant messaging, presence, desktop sharing, and S4B-to-S4B calling stay in S4B. Non-S4B calls use Placetel with UC-Desktop as the add-in front end.

Configuration of the add-in is done through the branding process and through the main configuration file. The standard UC-Desktop installation is used with the addition of a single registry setting.

The add-in integrates directly with Microsoft S4B and relies on the built-in integration between S4B and other Microsoft products. If S4B displays a calling option in a Microsoft product and that call goes through S4B, then the add-in is able to send the call through Placetel UC-Desktop.

The following figure depicts the high-level network architecture.

Supported Features

The following features are supported by the UC-Desktop for S4B:

  • Add-in installation with UC-Desktop installer
  • Add-in update using UC-Desktop installer
  • Authentication towards Placetel in standard UC-Desktop login window
  • Calling S4B contacts using a phone number
  • Calling a new number in S4B
  • Built-in S4B integration with other Microsoft products such as Outlook, SharePoint, Office, and Internet Explorer
  • Calling any tel: link using S4B add-in (based on built-in S4B functionality, only tel: format is supported)
  • Calling from any application (requires S4B Select Dial add-in)
  • Calling from phone (over Xtended Services Interface [Xsi])
  • Calling with VoIP (over Session Initiation Protocol [SIP])
  • Escalating audio calls to video
  • UC-Desktop call status reported to S4B so Busy In Call presence can be shown there (does not require Extensible Messaging and Presence Protocol (XMPP) to be enabled on the UC-Desktop side)
  • Video call (when the default is set to “video” by the end user in the Windows task bar UCDesktop icon)

Xsi, VoIP, and video calling are available through the UC-One license and can be disabled through configuration.

Call settings and usual call management features of UC-Desktop-initiated calls such as call transfer are available independently of S4B integration. This functionality must be enabled via configuration. For additional information, see the UC-Desktop for Desktop Configuration Guide.

System and Software Version Requirements

UC-Desktop system requirements are the same with or without the S4B add-in. For details, see the UC-Desktop (Desktop, Mobile, and iOS and Android Tablet) Product Guide or the UC-Desktop for Desktop User Guide.

The following are additional requirements for the UC-Desktop for S4B.

  • Windows

    • Windows 7
    • Windows 8
    • Windows 8.1
    • Windows 10
  • Lync/S4B

    • Lync 2010 32-bit
    • Lync 2013 Basic 32 and 64-bit
    • Lync 2013 Standard 32 and 64-bit
    • S4B 2015 32 and 64-bit
  • UC-Desktop 21.2.0 or newer

  • Windows administration rights (due to required registry entry)

Placetel Requirements

With UC-Desktop for S4B, there are no additional Placetel requirements on top of usual UC-Desktop configuration.

S4B configuration is outside of the scope of this document as it is expected that companies have configured and deployed, and now support S4B on their own. Called numbers that are not in SIP URI format in S4B use UC-Desktop for calling.

However, the following items are to be considered if applicable:

  • S4B Click to Dial add-in must be activated to place calls from Internet Explorer:
    • Go to Internet Explorer, open Tools → Manage Add-ons → Tool bars and Extensions and then enable the S4B Click to Dial Add-In.
    • In the Internet Explorer Tools menu, select S4B Click to Call and check “Enable number detection”.
  • Call from any application with using F8: Support for this functionality is dependent on users installing S4B Select Dial ( https://gallery.technet.microsoft.com/Lync-Copy-Dial-Just-Select-3c426244 ), which provides F8 functionality with S4B.
Special Note - Licensing and Client Use:
  1. The Placetel UC-Desktop with Lync Integration is a Site based license and will convert all new and existing UC-One clients within the specified Customer Site to “Dialer only” mode.

  2. The UC-Desktop for Lync and UC-Desktop for Windows clients should NOT be installed at the same time on an individual PC. If you have the regular UC-Desktop for Windows client installed, please uninstall the client before installing the UC-Desktop for Lync client.

UC-Desktop Cofugiration

Due to the special deployment model where S4B still manages presence and chat as well as S4B-to-S4B calls, S4B Integration is recommended to be used with the following general settings:

  • XMPP: Disabled (UC-Desktop as soft phone only) with one of the following calling options enabled in the Windows system tray menu:
    • Audio
    • Video call
    • Call from Phone
  • Video: Enabled (can be disabled through configuration, if preferred)
  • Contacts: Full directory disabled
  • Call History using Xsi: Enabled
  • Live Search: Disabled
  • UC-Desktop Outlook add-in MUST be disabled
  • Auto show communications window: Enabled

For more information on UC-Desktop Release 21.1.0 configuration, see the UC-Desktop Configuration Guide. The S4B add-in must be specifically enabled in the main configuration file. Additionally, when making a build of the UC-Desktop installer, the S4B integration must be specified at the branding level for the installer.

Migration for Existing S4B Users

When existing S4B users start using the UC-Desktop for S4B Communicator Client, the S4B user interface remains the same as before. The only exception is the dial pad that appears after installation (if it was not there before).

The calling experience is different in that when calling non-S4B numbers, the UC-Desktop communication window appears.

If there are users with both S4B and UC-One running with full feature sets (not the intended setup), both should work. In this case, UC-One tries to have the same presence on both sides with a predefined mapping between S4B and UC-One presence states.

Interoperability Status

This section provides the known interoperability status of the UC-Desktop for S4B with Placetel. This includes the version(s) tested and supported capabilities.

Verified Versions

The following table identifies the verified UC-One Add-in for S4B and Placetel versions. Testing was done in February to March 2015 and May 2015.

The following table lists specific UC-One Add-in for S4B versions that Placetel identified as compatible and should interface properly with UC-One. Contact Placertel Technical Assistance Center (TAC) for any questions concerning maintenance and compatible releases

Lync/S4B R16.1 R16.3 R17
2010 i i OK
2013 Basic/32-bit i i OK
2013 Basic/64-bit i i i
2013 Standard/32-bit i OK OK
2013 Standard/64-bit OK i OK
2015 OK OK OK

i = release lineup not officially tested

known issues

The following known issues have been observed.

Key Summary
BTUC-8051 UC-Desktop cannot add items to Lync call history (Lync limitation).
BTUC-7780 Lync presence occasionally does not revert to available after terminating call (only applies if UC-Desktop presence is enabled).
BTUC-8628 Skype for Business status not updated to Busy In Call when UC-Desktop Presence/XMPP disabled. For supported parameter combinations, see the UC-Desktop for Desktop Configuration Guide.
BTUC-7859 [LYNC] Not able to start N-way call from Lync (out of scope).
BTUC-8001 UC-One GUI brought to foreground when placing a call from Lync (working as designed).
BTUC-7763 [LYNC] Calling bridge from Lync via UC-Desktop not working (not supported by Lync).
BTUC-7756 Handle conference calls/calling with more than 1 contact selected.
BTUC-8277 Irregularities in call handling with SFB 2015 and UC-Desktop.



Once you receive an email indicating you have been given access to the Desktop client, log in to the MyPhone Portal to download the client installer. In the My Features / Meine Funktionen tab, select the S4B Client:

Click the Download button for your Operating System and follow the steps below:


  • Double click the installer executable and follow the installation instructions Launch UC-Desktop client
  • Launch UC-Desktop client


  • Double click the disk image
  • Copy the application into th „Applications“ folder
  • Launch UC-Desktop client

On first launch, you will be prompted to sign in. Enter your username listed in MyPhone and your password to MyPhone

Select if you would like Placetel UC - Desktop to remember your password
Select if you would like Placetel UC - Desktop to automatically sign you in on subsequent launches

Click Sign In

NOTE: If you have chosen automatic sign in, you will be automatically signed in and taken to the contact list upon subsequent Placetel UC – Desktop launches. Otherwise, you will be presented with the sign in screen.

After logging in, a popup dialog may appear informing you about emergency calls.

You may also see a banner in the Main window related to emergency calls. Depending on your service provider settings, emergency calls may not be allowed. In this case, calling an emergency number displays a popup dialog. A notification message in the Main window may also display.


There are no additional security requirements for the UC-Desktop for S4B.


Ticket eröffnen Status Kontakt Remote-Support