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Simultaneous Ring

    Question

  • Hi,

    I have my Lync server configured with a SIP Trunk (direct SIP, non official Lync SIP provider) and calls are working great. I'm trying to get simultaneous ring working with my cellphone but it doesn't work and I think I know why...

    In the logs/packet capture, the call to my cellphone is sending the caller id of the original caller in the FROM. My SIP provider tells me that because the number in the FROM is from another network it can not complete the call as this is effectively 'spoofing' the callerid.

    Any ideas how to fix?

    Many thanks!


    Thanks Christoph
    Tuesday, December 13, 2011 2:35 AM

Answers

  • Hi Christoph,

     

    I had exactly the same issue with a SIP trunk/Lync deployment, where calls forarded to external parties (including simultaneous ring) would fail. It was due to the SIp trunk provider identifying the source number received as not part of the configured number range for that particular customer: call dropped.

     

    From the SIP trunk provider, this is a security feature. The SIP trunk provider I used did not support authentication, they received calls from a nominated public IP only. Dropping the call from a source number the ITSP doesnt recognise prevents potential modern day phone "phreaking".

     

    Solving the issue in my enviromnet was easy because I had a Session Border Controller between the SIP trunk and the Lync environment. From the SBC you can manipulate any number you want, so if the call came from a number that was not part of the configured number range, I stripped it and replaced it with the company's main number. This is what a "normal" ISDN service provider does when it sees a source number it doesnt recognise. I do not believe there is a way to manipulate this number from the Lync environment.

    Wednesday, December 21, 2011 12:00 PM
  • Modify your mediation server config file to include referred by in the header for the sip
    trunk provider to use to enable call forwarding and simultaneous ring: http://unitycomms.wordpress.com/2011/08/04/forwarded-calls-dont-contain-the-called-partys-number/


    -Chad

    Thursday, May 10, 2012 4:47 AM

All replies

  • Dear Friend,

    Did you check this - when you add Simultaneous ringing the number which you added should be normalized  on your client. If its working and ringing, Want me to know about is this Direct SIP or through the Mediation GW?, If gateway is front you have to check the Gateway side and if Direct SIP to LyncFE its a Problem in SIP provider side according to my experience.


    Madushka Dias : MCITP(Lync Server 2010 Administrator) & MCTS - Active Directory) - http://uctechi.blogspot.com/ | Live - madushka@live.com | If got your answer don't forget to Rate as an Answer
    Tuesday, December 13, 2011 1:49 PM
  • Hi,

    you can try with disabling the REFFER from the voice route and see whether it's working. Also this is the normal behavior of this scenario and you may need to have the certified Gateway in middle of the SIP Trunk and the Mediation server to get it working as it should.

     


    Thamara. MCTS, MCITP Ent Admin, Specialized in U.C Voice OCS 2007 R2
    Tuesday, December 13, 2011 4:03 PM
  • Hi,

    Yes the ssimultaneous ring number is normalized. I can transfer lync calls to this number because a transfer uses the caller id of my lync client. Simultaneous ring however trys to send the caller id of the original caller.

    The error from the SIP providers gateway is "500 internal server error" but asking the provider they have advised its because the presented FROM caller id does not below in their network so they can not connect the call.

    I have disabled REFER on the route but this has not made any difference. How would a certified gateway help me in this situation? What does it do that my provider does not? The problem seems to be Lync using the original callerid in the FROM parameter...

    Thanks for your help guys


    Thanks Christoph
    Tuesday, December 13, 2011 9:16 PM
  • Hi,Chrisoph,

    In Lync Server 2010, direct SIP is configured between a Microsoft Lync Server 2010, Mediation Server and an IP-PBX. The Lync Server 2010, Mediation Server connects both signaling and media to SIP peers (that is, gateways, Session Border Controllers (SBCs), proxies, IP-PBXs, and so on). For a gateway, SBC, proxy, and IP-PBX to connect to the Lync Server 2010, Mediation Server, it must support certain requirements. The direct SIP peer must support the following:
    • SIP over Transmission Control Protocol (TCP)
    • G.711 codec
    • RFC2833 for dual-tone multifrequency (DTMF)

    Direct SIP with simultaneous ringing in Lync Server provides users the ability to receive inbound calls on both Lync 2010 as well as on their IP-PBX phone.When an inbound call is routed to Lync Server, it sends the SIP INVITE to all the registered endpoints of the callee based on the user’s preferences, including the IP-PBX phone specified by the user. To ring the user’s IP-PBX phone, Lync Server forwards the SIP INVITE to the IP-PBX by using the Mediation Server across the direct SIP connection.

    So if your direct sip provider doesn't translate the incoming call to the correct format before it sending to cellphone,it will fail.But if you have a certificate gateway it will help you normalization the call when it go through to sip then to the cellphone.

    Regards,

    Sharon


    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.
    Wednesday, December 14, 2011 7:05 AM
  • Hi,Chrisoph,

    Any updates here?

    If you have fixed the issue please kindly share us the solution.

    Regards,


    Sharon Shen

    TechNet Community Support

    ******************************************************************************************************************************************************* 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 memb
    Tuesday, December 20, 2011 10:36 AM
  • Hi Christoph,

     

    I had exactly the same issue with a SIP trunk/Lync deployment, where calls forarded to external parties (including simultaneous ring) would fail. It was due to the SIp trunk provider identifying the source number received as not part of the configured number range for that particular customer: call dropped.

     

    From the SIP trunk provider, this is a security feature. The SIP trunk provider I used did not support authentication, they received calls from a nominated public IP only. Dropping the call from a source number the ITSP doesnt recognise prevents potential modern day phone "phreaking".

     

    Solving the issue in my enviromnet was easy because I had a Session Border Controller between the SIP trunk and the Lync environment. From the SBC you can manipulate any number you want, so if the call came from a number that was not part of the configured number range, I stripped it and replaced it with the company's main number. This is what a "normal" ISDN service provider does when it sees a source number it doesnt recognise. I do not believe there is a way to manipulate this number from the Lync environment.

    Wednesday, December 21, 2011 12:00 PM
  • Hi Damien and Sharon,

    I do have simultaneous ring to my desk phone working fine (Lync to Asterisk) but not to my cellphone.

    Damien, what you've described sounds exactly like the problem I've got. The ITSP is dropping the call because Lync is sending the original CallerID whicn is not part of my number range.

    I don't have my own SBC, my Lync environment connects directly to them so I wonder if there is something else I can do?

    Is it normal behaviour for IP-PBX systems to use the original caller ID when doing 'simultaneous ring' functions? or is it just a Lync thing?

    Many thanks

    Christoph


    Thanks Christoph
    Wednesday, December 28, 2011 1:02 AM
  • Modify your mediation server config file to include referred by in the header for the sip
    trunk provider to use to enable call forwarding and simultaneous ring: http://unitycomms.wordpress.com/2011/08/04/forwarded-calls-dont-contain-the-called-partys-number/


    -Chad

    Thursday, May 10, 2012 4:47 AM
  • Thanks philldogger,

    Thats more along the lines of the solution I was expecting! I've tried it and I can see the new REFERRED-BY header but the call still fails, probably because the ITSP doesn't knwo what to do with this header.

    Thanks!


    Thanks Christoph

    Thursday, May 10, 2012 9:27 PM
  • No problem, some ITSPs you contact about it, mine however is not one in interop (Paetec/Windstream) and I'm doing  sip trunking directly from mediation server to their SBC (yes the do SIP over TCP).  When I asked them if they could take the referred-by header they said no, but offered to enable a feature on their end called Enterprise Trunking which essentially allows foreign numbers in the FROM header to place calls as long as the call came via mediation server at some point (which it does during a transfer or sim ring).

    -Chad

    Thursday, May 10, 2012 10:36 PM
  • Interesting.

    I also am doing "Direct SIP' to their SBC from my mediation server.

    I'm in touch with my ITSP now and they are looking into it.


    Thanks Christoph

    Thursday, May 10, 2012 10:46 PM