Lync 2013 For Mobile Clients. Lync 2013 mobile apps now include voice over IP VoIP and video over IP capabilities in addition to contacts presence and IM features. I tried the Lync 2013 client on iPhone iOS 6 and Android 42 as well and on the competitions platform it works perfectly but on Windows own platform it fails.

Lync 2013 for Mobile Devices. Lync 2013 mobile clients provide enhanced presence IM Lync meetings and voice and video calls over the Internet or the cellular connection. I found the solution here.
Der Lync 2013 Client für Android muss also auf sehr viel mehr unterschiedliche HardwareUmgebungen Rücksicht nehmen also der Lync 2013 Mobile IOS.
You can use mobility table section in Capacity Calculator to see if extra server is required. I hope someone can. Sorry for delayed reply. You need to create an internal DNS record for the external FQDN and point it to your external reverse proxy IP and allow hairpinning of the traffic.