Issue: Users getting a fast busy instead of voicemail prompts.
Recently multiple user complaining about voicemail. Users received missed calls to their inbox. Caller gets a fast busy tone instead of voicemail prompts.
Lync QoE report shows multiple failure with diagnostic ID 15035 - Failed to route rejected by Exchange server. And ID 15030 - Failed to route to Exchange Server.
Multiple user was affected so started look Lync server side.
First I checked Lync FE Server found multiple error event ID: 44022.
An attempt to route to an Exchange UM server failed. The attempt failed with response code 504.
Later ran Test-CsExUMConnectivity command let however test result was failed.
When I checked get certificate on exchange server and found certificate is not assigned UM service.
Then assign certificate to UM service on exchange server using power shell:
Enable-ExchangeCertificate -Thumbprint 5113ae0233a72fccb75b1d0198628675333d010e -Services 'UM, UMCallRouter'
You can assign certificate using ECP or EAC:
1. In the EAC, navigate to Servers > Certificates.
2. In the list view, select the certificate that you want to assign to the Unified Messaging and UM Call Router services, and then click Edit .
3. On the
page, select Services, and then select UM and UM call router.
4. Click Save.
However when I assign certificate to UM service it gives me error. ‘The certificate with <> can’t be enabled for Microsoft Exchange Unified Messaging because it is currently set to run in TCP mode only. Change the mode to TLS or Dual and then run this cmdlet again.’
You can use Get-UMService and see the startup mode: it will be TCP that’s why certificate doesn’t get assigned.
Use the Set-UMService cmdlet to set the properties on a Microsoft Exchange Server 2013 Mailbox server or Exchange Server 2007 or Exchange Server 2010 Unified Messaging server that's running the Microsoft Exchange Unified Messaging (UM) service.
Enables the Microsoft Exchange Unified Messaging service on the Mailbox server MyUMServer to start up using dual mode.
Set-UMService -Identity MyUMServer -IPAddressFamily Any -UMStartupMode Dual
1. Generate new certificate with CN as Server FQDN, if you have certificate then assign exiting certificate.
2. In my case existing is good.
Enable-ExchangeCertificate -Thumbprint "AF6203FFF24EAAFB43A940EB606261E5A3156BF2" -Services 'UM’
To complete configuration you have to Restart Microsoft Exchange Unified Messaging Service on ‘MyUMServer’.
After Service restart you test again UM. Now Test comlet passed.