Unable to A/V with external SfB users RRS feed

  • Question

  • I've setup an on-premises Skype for Business environment consisting of:

    - Front-End Enterprise Pool, 1 server (with Mediation role)

    - Edge pool, 1 server

    A hybrid setup is created with the already existing Skype for Business Online environment, everything works as expected between the on-premises and Online environment. Also other Skype for Business Online environments can communicated with the on-premises Skype for Business users. I've tested a few other on-premises Skype for Business on-premises environments, those users can see presence and chat, but they are unable to audio or video chat (incoming and outgoing). Desktop sharing however is possible! Even when user A from organisation 1 and user B from organisation 2 are on the same LAN, it doesn't work.

    I've created many Lync and Skype for Business environments before, I cannot see that something is blocked in the firewall. It feels like an issue in a Conferencing or Federation setting, but I don't know what?

    Identity                               : Global
    AllowAnonymousUsers                    : True
    AllowFederatedUsers                    : True
    AllowOutsideUsers                      : True
    BeClearingHouse                        : False
    EnablePartnerDiscovery                 : True
    DiscoveredPartnerVerificationLevel     : UseSourceVerification
    EnableArchivingDisclaimer              : False
    EnableUserReplicator                   : False
    KeepCrlsUpToDateForPeers               : True
    MarkSourceVerifiableOnOutgoingMessages : True
    OutgoingTlsCountForFederatedPartners   : 4
    DnsSrvCacheRecordCount                 : 131072
    DiscoveredPartnerStandardRate          : 20
    EnableDiscoveredPartnerContactsLimit   : True
    MaxContactsPerDiscoveredPartner        : 1000
    DiscoveredPartnerReportPeriodMinutes   : 60
    MaxAcceptedCertificatesStored          : 1000
    MaxRejectedCertificatesStored          : 500
    CertificatesDeletedPercentage          : 20
    SkypeSearchUrl                         : https://skypegraph.skype.com/search/v1.0
    RoutingMethod                          : UseDnsSrvRouting
    Tuesday, July 11, 2017 1:27 PM

All replies

  • Hi Marco Schilder,

    According to your description, did you mean that you can’t AV call between the SFB on premise environment?
    Are there any error messages when you do AV call?

    For this issue, please try to check the DNS configuration, the following document is for your reference

    Make sure the port 5061 is open, also check if you have the correct configuration of Lync federation, please refer to

    Also you could use Microsoft remote connectivity analyzer check if there are any errors


    Alice Wang

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    Wednesday, July 12, 2017 6:13 AM
  • Hi Alice,

    Yes. When I try to communicate with an external (federated) Skype for Business on-premises user, I can only chat and share a desktop, but no audio or video. The connection just drops almost instantly 'The call couldn't be completed' and the calling party receives a missed call. Strangely it works fine with federated Skype for Business Online users.

    DNS should be ok, the sip. lyncdiscover. and _sipfederationtls_.tcp records all point to the on-premises Skype for Business.

    Port TCP 5061 is open, else I would nog be able to chat.

    Microsoft Remote Connectivity analyser (with the A/V option enabled) gives OK.

    Wednesday, July 12, 2017 2:51 PM
  • Hello Marco,

    1) You may want to test federation between you and your federated partner, same test should be performed from your federated partner. Ensure this is successful.

    Test-CsFederatedPartner -TargetFqdn poolinternaledge.contoso.org -Domain google.com -verbose

    TargetFqdn is your internal edge pool name

    2) telnet to access edge on port 5061 and 443 should be successful on both sides

    3) You may want to capture Client log while reproducing the issue on both sides and check for error.

    ex:- Error 1034 or Error 1046 etc

    • Proposed as answer by Alice-Wang Thursday, July 13, 2017 5:48 AM
    Wednesday, July 12, 2017 10:11 PM
  • Hi Alice,

    The Test-CsFederatedPartner command was successful (only when I ran PowerShell as an administrator though). The ports 5061 and 443 are available on both sides.

    I have not been able to filter or see the client errors you've mentioned.

    Friday, July 21, 2017 1:00 PM
  • Hi Marco,

    Thanks for your response.

    Please try to use snooper to collect SFB client log.


    Alice Wang

    Please remember to mark the replies as an answers if they help and unmark them if they provide no help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    Monday, July 31, 2017 7:26 AM