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Lync intermittent one way audio half way through a call. RRS feed

  • Question

  • Current situation is that

    Lync 2013 standard edition server, Lync 2013 Mediation server connected to a SIP trunk on a separate voice vlan (2nd NIC on mediation server).

    What happens is that on inbound or outbound PSTN call via SIP trunks, some calls (1 in 100) will go on successfully initially. All of a sudden, audio to either direction may. This issue has been happening randomly and the monitoring / centralized logs do not show anything (only shows normal call clearing). The Sip trunk providers Wireshark capture shows and can hear media from both directions, not just Lync.

    Any ideas ?


    Murali Krishnan| My blogs: UnifiedMe | Twitter: @Mkris9

    Monday, September 9, 2013 2:17 PM

Answers

  • changed provider to a lync certified - and it works beautifully.

    Murali

    If you see a post that helped you please click "Vote as Helpful" and if it answered your question, please click "Mark as Answered.
    Murali Krishnan | My blog: UnifiedMe | Twitter: @mkris9

    Wednesday, November 20, 2013 4:54 PM

All replies

  • Hi - does the issue occurs with a fixed pattern (e.g. after a specific time)?

    check this thread for reference but there are many more if you do a search in these forums.

    http://social.technet.microsoft.com/Forums/lync/en-US/68a338e3-00b2-47b3-8132-c1d708d81616/intermittent-oneway-audio-and-dropped-calls


    Alessio Giombini | Microsoft Solutions Architect | Twitter: @AlessioGiombini
    Lync 2013 Detailed Design Calculator: try it at http://goo.gl/jU1hZR

    Monday, September 9, 2013 2:42 PM
  • NOpe, no fixed pattern unfortunately. yes, I have seen that, but didn't help.

    I've checked codec, media bypass, firewall properties, AV etc etc etc...


    Murali Krishnan| My blogs: UnifiedMe | Twitter: @Mkris9

    Monday, September 9, 2013 2:57 PM
  • that thread suggested the issue was on the SIP carrier end, I take you've also checked with them and they took and analysed specific traces?

    Alessio Giombini | Microsoft Solutions Architect | Twitter: @AlessioGiombini
    Lync 2013 Detailed Design Calculator: try it at http://goo.gl/jU1hZR


    Monday, September 9, 2013 3:06 PM
  • Yes... actually I did. The SIP trunk carrier is a non-Lync certified one (I know.. :):) ) and they are adamant that it is passing fine through their end.

    Murali Krishnan| My blogs: UnifiedMe | Twitter: @Mkris9

    Monday, September 9, 2013 3:15 PM
  • not certified, and how is the interoperability achieved, direct SIP to the carrier's SBC or you have a media gateway?

    have you tried to tweak any of these values about the trunk? http://memphistech.net/?p=169


    Alessio Giombini | Microsoft Solutions Architect | Twitter: @AlessioGiombini
    Lync 2013 Detailed Design Calculator: try it at http://goo.gl/jU1hZR

    Monday, September 9, 2013 3:32 PM
  • Sorry to be so vague initially - I tend to be a one-liner in everything which is why I have so much hard time writing my blog. :)

    Yes - Direct SIP to ITSP's SBC.

    I have configured MoH, so currently the values are on Enablesessiontimer - True, RTCPactivecalls - False.

    What I have also done earlier is to disable AV on the mediation server as well. They have McAfee and I've had some funny issues with it before. So thought I'll give that a try.


    Murali Krishnan| My blogs: UnifiedMe | Twitter: @Mkris9

    Monday, September 9, 2013 4:16 PM
  • This problem may be related with the Mediation Server.

    Please check the configuration on Mediation Server with two NIC.

    http://blogs.perficient.com/microsoft/2009/02/ocs-mediation-server-nic-configuration-2/

    Check if you can find any errors on Lync Mediation Server.


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    Tuesday, September 10, 2013 7:12 AM
  • Thanks Lisa,

    Unfortunately, I already knew / checked Jeff's blog about this - I am using separate subnets for voice vlan as well as server vlan. There are no errors on Mediation server / monitoring server reports on any of the calls.

    I've started a continuous wireshark capture anyways.


    Murali Krishnan| My blogs: UnifiedMe | Twitter: @Mkris9

    Tuesday, September 10, 2013 12:06 PM
  • Can confirm through Wireshark that both the voice VLAN NIC could hear both sides of the audio even when the Lync user could not hear the third party for over 5 seconds. Call continued successfully afterwards.

    Planning to change the 2 NIC configuration to a single NIC one. Any other suggestions ?


    Murali Krishnan| My blogs: UnifiedMe | Twitter: @Mkris9

    Wednesday, September 11, 2013 3:40 PM
  • If you have a monitoring server deployed, I recommend you review sessions with problems.

    If removing the 2nd NIC from the mediation implies you need to NAT to the SIP trunk, that might potentially introduce additional issues.


    Alessio Giombini | Microsoft Solutions Architect | Twitter: @AlessioGiombini
    Lync 2013 Detailed Design Calculator: try it at http://goo.gl/jU1hZR

    Wednesday, September 11, 2013 9:53 PM
  • Monitoring reports do not show anything, but normal call clearing if you disconnect the call. Else does not even recognise that the call had one way audio for 10 seconds. MOS, jitter etc is normal.

    Murali Krishnan| My blogs: UnifiedMe | Twitter: @Mkris9

    Thursday, September 12, 2013 6:45 AM
  • Any suggestions, anyone ?


    Murali Krishnan| My blogs: UnifiedMe | Twitter: @Mkris9

    Thursday, September 12, 2013 4:21 PM
  • If you are certain everything on Lync and SIP carrier side is perfectly normal, i'd point the finger to something related to networking.

    few possible next steps:

    - confirm any firewall, or IDS, or antivirus, or any other application doing packet inspection is not interfering

    - confirm switch ports are not the issue

    - if at all possible remove the VLAN and test


    Alessio Giombini | Microsoft Solutions Architect | Twitter: @AlessioGiombini
    Lync 2013 Detailed Design Calculator: try it at http://goo.gl/jU1hZR

    Thursday, September 12, 2013 5:07 PM
  • I had a response from another thread - http://social.technet.microsoft.com/Forums/lync/en-US/f3d358c9-e4d6-490b-8f8b-9fa28c30a489/sip-trunk-intermittent-one-way-audio

    What worked for them is as below. Will ask the infrastructure team to try it out.

    "For us it turned out to be deep packet inspections feature on our Juniper SRX Firewall. Once we disabled these features our problem went away. We disabled the following:

    • SCCP (Skinny protocol)
    • MGCP (Media Gateway Control Protocol – another PSTN VoIP protocol)
    • H323 (Video based but we disabled it anyway) 
    • REAL (Real time streaming protocol, can impact UDP)
    • RTSP (Real time streaming protocol, can impact UDP) "

    Murali Krishnan| My blogs: UnifiedMe | Twitter: @Mkris9



    Friday, September 13, 2013 7:52 AM
  • yes that matches with my last post -check everything does packet inspection in the path from Lync servers to SIP carrier's SBC.

    Have you had a chance to try yet?


    Alessio Giombini | Microsoft Solutions Architect | Twitter: @AlessioGiombini
    Lync 2013 Detailed Design Calculator: try it at http://goo.gl/jU1hZR

    Friday, September 13, 2013 8:35 AM
  • The client has applied the firewall changes - now its waiting game. :) 

    Murali Krishnan| My blogs: UnifiedMe | Twitter: @Mkris9

    Friday, September 13, 2013 9:05 AM
  • still the same unfortunately. 2 out of 90 calls from pilot users had this issue.

    Murali Krishnan| My blogs: UnifiedMe | Twitter: @Mkris9


    Friday, September 13, 2013 3:51 PM
  • Recently faced a similar issue where the client had the SIP trunk passing through a Cisco ASA w/8.2x firmware. They did not want to update their ASA firmware or make any changes to it. We bypassed the Cisco ASA and terminated on an Audiocodes gateway. 

    No more intermittent audio issues since.

    Friday, September 27, 2013 6:47 PM
  • changed provider to a lync certified - and it works beautifully.

    Murali

    If you see a post that helped you please click "Vote as Helpful" and if it answered your question, please click "Mark as Answered.
    Murali Krishnan | My blog: UnifiedMe | Twitter: @mkris9

    Wednesday, November 20, 2013 4:54 PM
  • Thanks for all your help by the way. :)

    If you see a post that helped you please click "Vote as Helpful" and if it answered your question, please click "Mark as Answered.
    Murali Krishnan | My blog: UnifiedMe | Twitter: @mkris9

    Wednesday, November 20, 2013 4:56 PM