Calls to an international phone number fail when you use Cloud PBX with PSTN International Calling

When you dial an international phone number using Cloud PBX with PSTN International Calling in Skype for Business Online (formerly Lync Online), you experience one of the following symptoms:
  • Your call isn't completed successfully and you may receive an error. For example, when a user attempts a call to Australia by using the phone number format: +61 02 XXXXXXXX, the call will fail with the error: 
    number not in service
  • The following details are recorded in the UCCAPI logs from the Mediation Server:
    Error message: SIP/2.0 404 Not Found
    Reason: Gateway responded with 404 Not Found (User Not Found)
These issues occur because the user is leaving the trunk code of "0" (zero) in the phone number sequence. This results in an invalid phone number being passed to the PSTN when you use the Office 365 Skype for Business Online PSTN International calling service.  

With Skype for Business on-premises deployments, administrators frequently configure normalization rules to handle different dialing behaviors of users. However, when you use the Cloud, international phone numbers must be dialed with the full international phone number in the format of + (Country Code)(Area Code)(Local Number). In the earlier example, the phone number should be dialed using this phone number format: +61 2 XXXXXXXX.
Depending on the particular PSTN calling infrastructure and telephony carrier, users are accustomed to dialing numbers with the "0" (zero). Administrators remove this number in the dialing sequence elsewhere in the telephone infrastructure before this is passed to the carrier. At this point, there's no way to strip or normalize the phone number before its passed to the PSTN when you use the PSTN international calling feature in Skype for Business Online.

Still need help? Go to the Office 365 Community website.

Article ID: 3141415 - Last Review: 02/12/2016 22:04:00 - Revision: 1.0

Skype for Business Online

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