External callers don't hear ring tone when calling our Skype users. RRS feed

  • Question

  • Hello,

    We use Skype for Business 2015.

    External callers don't hear a ring tone when calling any of our Skype users numbers.

    Internal calls are fine and you can hear the ringing tone before a user picks up.

    What could be the issue?


    Wednesday, December 14, 2016 11:53 AM

All replies

  • what you are using for external access.?? SIP trunk direct? or sbc/GW?
    Wednesday, December 14, 2016 1:57 PM
  • Hello,

    We have a SIP trunk from Gamma.

    Wednesday, December 14, 2016 2:06 PM
  • did you try to see the logs? 183 sdp, 180 anything from service provider??? and what you are sending
    Wednesday, December 14, 2016 2:12 PM
  • We have raised it with the provider last night, but they are still trying to find out what is happening.

    We don't have access to this SIP trunk.

    I'm not an expert as you can tell, will any of these logs show on any of the Skype servers we have, we have OWA, Reverse Proxy servers and the main Skype for Business servers.

    Wednesday, December 14, 2016 2:35 PM
  • The call connects then it's quite, no right dial, then after 15 seconds (our default) it goes through to voicemail.  Customers hang up as they think the call hasn't gone through, but it has, they just can't hear the ring tone.
    Wednesday, December 14, 2016 2:45 PM
  • yes please start ocs logger on skype front end server and enable s4,sip stack options. Regards
    Wednesday, December 14, 2016 2:47 PM
  • so many logs created for my 1 inbound call, what should I be looking for, I've opened the file in snooper?
    Wednesday, December 14, 2016 3:54 PM
  • I see:

    Start-Line: SIP/2.0 100 Trying

    Start-Line: SIP/2.0 180 Ringing

    Start-Line: SIP/2.0 183 Session Progress

    Start-Line: SIP/2.0 200 OK

    Wednesday, December 14, 2016 4:04 PM
  • okay so would like to knw if ur sip service provider is lync qulaified or not and secondly i would like to know if lync is sending to your sip service provider 180 or 183? i think it is sending 183 to service provider and this is why service provider is opening the channel and they are hearing blank. Regards
    Wednesday, December 14, 2016 4:58 PM
  • Hi TB303,

    Did the issue happen to all external users or specific external user in your environment?

    If the issue only appeared on the specific user, please try to compare user attributes in AD between the affected user and other normal users. If the issue appeared on all users in your environment, please try to check the configuration of the enterprise voice, the following document is for your reference:
    Make sure your mediation server with the latest update.

    If the issue persists, please try to use SFB debugging tool collect more information for us.https://www.microsoft.com/en-us/download/details.aspx?id=47263


    Alice Wang

    Please remember to mark the replies as answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

    • Edited by Alice-Wang Monday, December 26, 2016 5:50 AM
    Monday, December 26, 2016 5:49 AM
  • Hello, I saw this issue. "External callers don't hear ring tone when calling our Skype users". did you ever get a good solution ?


    R Bosch

    Friday, April 21, 2017 3:00 PM
    • Question                    
      You cannot vote on your own post                            

      It was solved with audiocodes sbc solutions.

      in the ip profile we uses the right options (prack optional) en remote can playback

    Thursday, July 6, 2017 11:09 AM
  • This is because of the settings in SBC/Gateway at your end for SIP trunk.The gateway need to enable this.So you need to check with your gateway vendor about this.

    Also this may be related to the early media enabled on gateway side.

    Below is kind of same issue.This parameter may diffrent in different gateways.



    Jayakumar K

    Thursday, July 6, 2017 12:08 PM