A small number of users (~5/2500), that have the iPhone Lync 2013 Mobile Client (Version 5.7) installed on their iPhone receive an iPhone call from the number that is calling their work phone if the call is not picked up on their work phone or Lync 2013 Application on their computer, within ~20 seconds of ringing. 

 - (Expected Behavior) If the iPhone Lync Application is actively open or open in the background and logged into; and a call is placed to the users Work phone number, theyll instantaneously receives a Lync call on their iPhone through the Lync Application.

 - (Expected Behavior) If the iPhone Lync Application is open and NOT signed into or closed and NOT signed into; and a call is placed to the users Work phone number, their cell phone will not ring at all.

 - (Unexpected Behavior) If the iPhone Lync Application is closed and the user has not formally signed out of the Lync Application; and a call is placed to the users Work phone number. She will receive an iPhone call after 17-21 seconds. The call will route through her iPhone "Phone" application and is answerable.

Our Lync server reflects the logging in/out of the users iPhone Lync App appropriately.

I verified that call forwarding was completely off on both, the users local Lync Application on their computer and the iPhone Application.

I tried uninstalling/reinstalling the Lync Application on her iPhone.

I verified that all settings were identical to my iPhone Lync Application (which is working properly).

I have tried removing all traces of her cell phone number from her Computer's Lync Account, Active Directory, and Outlook Web Applications Phone Settings tab.

I tried to sign in/out multiple times while over both WiFi and 4G.

I tried completely shutting down the Lync Application on her computer and taking it off the network, and placing a call to her work number, the call still routed to her phone after 20 seconds.

I played with changing the call forwarding setting on the computers local Lync Application from "Unanswered calls will go to: Voice Mail in 20 seconds" to 5 seconds and 60 seconds. When changing it to 5 seconds the iPhone never got the chance to ring because the Voicemail kicked in after 5 seconds. When at 60, her iPhone still began ringing at ~20 seconds and continued to ring until the 60 seconds was up and the voice mail kicked in.

Does anyone have suggestions on what to test/try next?

Thanks, Dan

• Edited by DanOBrien 13 hours 40 minutes ago adding detail

I would try removing Lync mobile from her iPhone and then test setting it up on a different iPhone to see if you can repeat the issue that way, if you can, it's something with Lync/Exchange, if it doesn't repeat, it's something with her phone.

If you set simultaneous ring on your phone to a different number, does the cell phone still ring when the work phone is called? If you then turn it back off does the problem disappear? There was an issue on a version of the 2010 mobile where a forwarding number could be entered twice, wondering if this is something similar.

Thanks for the replies. I'll get a hold of a user and test both of your suggestions. 

• Edited by DanOBrien 12 hours 10 minutes ago

I've been meaning to write up the blog on this for nearly four months. One thing you should be aware of is that when you login to your mobile client it asks you for your mobile phone number.  What this is really doing is creating a static registration in the database for your user. 

So let's assume you did this.  A call comes into Lync.  The server will ring your end-point and also the static registration of the mobile phone via the Lync Client.  If for some reason that client isn't accessible (I see this on iPhones all the time where the users "exits" the program via the multitask screen and doesn't receive notifications anymore) the Lync server will fallback to ringing the device via the PSTN instead.  It does this regardless if Sim Ring is enabled or not in the client.  This is a "feature" of the client to never miss a call.

The static registration is valid for 21 days in the database so after a while it just goes away on it's own.  Typically I've found that if you remove the Lync Client, add it back, enter the same mobile number and then correctly log off the client it goes away. One other time I had to manually hack the database to make it go away (super not supported of course).

Richard

You could also modify the web.config file for UCWA located here:

C:\Program Files\Microsoft Lync Server 2013\Web Components\Ucwa\Ext

C:\Program Files\Microsoft Lync Server 2013\Web Components\Ucwa\Int

And modify the following entry from 15 days to 1 day.

<add key="MobileApplicationExpiryTimeInDays" value="15"/>

To

<add key="MobileApplicationExpiryTimeInDays" value="1"/>

A reboot would be required, IISreset isn't enough.