Send an IM with UCWA - Step 1 - Prerequisites

Installing and Configuring UCWA

Before you can install and configure UCWA, ensure that all nodes in your Lync environment (Front End, Edge, Director, etc.) are fully patched and up to date with the latest Cummulative Updates.

Microsoft have a great resource that summarizes the updates available, which you should check regularly.

https://technet.microsoft.com/en-US/office/dn788954

Bootstrapping the Environment

Once up-to-date, you need to run the Bootstraper application on each Edge, Front-End and Director server in your environment, from the Lync Server Management Shell (not Powershell).

%ProgramFiles%\Microsoft Lync Server 2013\Deployment\Bootstrapper.exe

Configuring "Allowed Domains"

UCWA controls access by only permitting access from a set of domain names that you specify, to help avoid Cross Domain exploits.

Your UCWA application or handler needs to be hosted on an IIS site with a fully qualified domain (FQDN), such as ucwa.contoso.com. Contoso is regularly used by Microsoft for examples and tutorials, so we'll use it here .

Every variation of the FQDN (http, https, different ports, etc.) must be added to the internal list of Allowed Domains.

Again, using the Lync Server Managed Shell, kick off the following commands on each and every Front End, Edge and Director server you have. The 2nd line is wrapped for readability.

$x = New-CsWebOrigin -Url "{https://ucma.contoso.com}"
Set-CsWebServiceConfiguration -Identity "My UCWA Application" 
        -CrossDomainAuthorizationList @{Add=$x}