Skype for Business Cloud Connector Edition - Inbound / Outbound calls fail RRS feed

  • Question

  • Hello

    I just set up the Skype for Business Cloud Connector Edition on my Hyper-V Host. The Deployment finished without any failures after fixing some issues.

    We have a new O365 Tenant with an integrated default domain, on which we have created the external dns records.

    I have set up everything like described in the manual of the 'configure skype for business cloud connector edition' from microsoft and it looks like everything is working fine.

    the users have also assigned their phone numbers.

    when i do an internal call to another user of the domain, the call is working fine and everything is great.

    but when i try to make an outbound call, the windows for the calls opens and just breaks up and fails.

    our sip provider has set up a 'media gateway' with a sip-trunk to the pstn. 

    our Mediation Server from the CCE is behind a NAT Firewall with SIP-ALG - so the source ip address of the sip packets should stay the public IP. The mediation server uses a different public ip as the external edge interface. they are both behind NAT at the moment. With the edge NAT should not be a problem and is supported like described on the configuring website. 

    The firewall rules are all OK and have the ports assigned like described on the microsoft website. We have also set the public souce IP for the external edge and the mediation server.

    Could that be a problem for the sip traffic?

    Or does the mediation server of the cce need a second NIC with the public IP assigned?

    I thought the NAT to the mediation server would't be a problem because our sip provider uses a 'media gateway'. 

    I don't know id the 'media gateway' is just the same like a regular audiocodes or if it is something else just like a configuration for skype for business server.

    I have also seen on wireshark:

    The Edge server is communicating with the office365 server and with the mediation server - everything is looking fine.

    The mediation server is communication with our sip provider (media gateway) and with the edge server and the other servers of our deployment.

    But - There is sometimes a tcp retransmission in wireshark when the mediation server is communicating with the sip provider media gateway. I dont know if this means some issues or if this is Ok.

    when i l have a look at the logs for the users with the skype for business online powershell module i see the following failure:



    possible server configuration issue

    cannot route from and to domains in this combination

    the domain of the message that corresponds to remote peer (external) is not shared between local and remote depoyments

    Has anyone a tip or a solution for me?

    It be very happy for any help!


    Kind regards


    Wednesday, March 22, 2017 11:21 AM

All replies

  • Hi fabiok._,

    Based on your description, I understand the issue just appeared when you did the outbound call. Is that right?

    In order to narrow down the issue, please help us confirm the following questions:
    Did the issue only appeared on the specific user?
    Are there any error message when you make the outbound calls?

    You could refer to the following blog then check if the SIP trunk is correct.
    Please try to use SFB debugging tool check if there are any errors


    Alice Wang

    Please remember to mark the replies as answers if they help.
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    • Proposed as answer by Alice-Wang Friday, March 31, 2017 9:10 AM
    Thursday, March 23, 2017 8:42 AM
  • Deleted
    Thursday, March 23, 2017 11:07 AM
  • Outbound Calls Failing following indicate that the external Edge certificate does not contain sip.domain.com in the SAN name matching the SIP domain of the user placing the call:


    504  Server time-out

    ms-diagnostics:  1017;reason="Cannot route From and To domains in this combination";cause="Possible server configuration issue";summary="The domain of the message that corresponds to remote peer (external) is not shared between local and remote deployments";external-domain="skylabca.com";external-type="domain-type-local";internal-domain

    The CCE scripts will run a check for this and will return an error. However if you manually update certificate or failed to define all sip domains in use this can happen. Please update the certificate with sip.domain.com for all supported sip domains. Also be sure that the Cloud Connector configuration file has all supported sip domains defined.

    After the certificate is updated, you will need to import/assign to CCE Edge server. If running CCE build 1.4.2, you can do this by running the following in Admin PowerShell on the CCE Appliance Server:
    Set-CcExternalCertificate -Path <Full Path including Filename> -Target EdgeServer -Import

    If running build older than 1.4.2, you'll need to manually import/assign on CCE Edge either using Skype for Business Server Deployment Wizard or

    PowerShell https://technet.microsoft.com/en-us/library/gg398518.aspx

    Friday, April 7, 2017 3:27 PM