Hi,

Recently we have had an issue with one of our Lync deployments where they have Lync 2010 On-Prem but UM hosted through Office 365.

It was working perfectly but we're not sure what has caused it to stop.

The problem only occurs when you try and call voicemail from a Lync Phone Edition device or Lync on a PC. If you call the subscriber number from external, it connects fine, it is also fine if you call from external to an internal number and get redirected to their voicemail.

Visual voice mail works OK as well as the other EWS features.

When this fails, in event viewer I get a 44009 LS Exchange Unified Messaging Routing event, which basically says "Dialplan is not configured properly". 

When running the Lync Logging Tool the only error i can see is "Call failed to establish due to a media connectivity failure when both endpoints are internal"

I have checked all DNS and firewall rules and they are as they should be. Federation also works perfectly.

Any suggestions would be greatly appreciated.

Regards

Mark

Take a look at this and verify if you have the right Dial plan for UM

http://help.outlook.com/en-us/140/ms.exch.ecp.newumdialplan.aspx

Full article here for Lync Server and UM Online 

http://help.outlook.com/en-us/140/gg702674.aspx

Had a client that hasn't made changes in 6 months have Voice mail stop working, sip logs from the Edge server reported: "Prompts are not in a consistent state. Object: Dial Plan."

The fix was to remove all recorded audio files from the Auto Attendant (recreating the Dial Plan would have the same effect), seems as though O365 corrupted the files.

Client posted on 0365: http://community.office365.com/en-us/forums/158/p/212427/646671.as