 <p>Angular is having normal url as href:mailto as whitelist. But few attribute need to loaded from the security point of view. To start an IM through angular we need to add sip to whitelist like this</p> <pre><code> var app = angular.module( 'myApp', [] ) .config( [ '$compileProvider', function( $compileProvider ) { $compileProvider.aHrefSanitizationWhitelist(/^\s*(https?|sip|chrome-extension):/); } ]); </code></pre> <p>It will add sip to whitelist and the Lync application will start when clicked in the Icon. This change is to be made in app.js.</p>