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Lync Server 2010 requires 2 responses to sip NEGOTIATE request to send INVITE RRS feed

  • Question

  • Hello!

    We are trying to deploy MS Lync Server 2010 but can't understand how it's processing SIP messages at all.

    Scenario: Make call from MS Lync 2010 client to second party using TLS transport. When Lync Server receives INVITE from Lync client it generates and sends NEGOTIATE message to second party. Second party should respond with 200 OK and any another message (we tryied several messages like INFO, another 200 OK) and ONLY after that Lync Server sends INVITE request to second party. We do not use compression for this scenarion.

    If the second party doesn't respond with 200 OK and any other messages, Lync Server doean't send any requests. If we send only 200 OK to NEGOTIATE request Lync Server still doean't send INVITE from client and seems like it waits another message from the second party.

    We are really confused about such behaviour. Please explain initial part of basical SIP call from the Lync Server 2010 side.

    Also we compared the behaviour of Lync Server 2010 with Lync Server 2013 and Lync Server 2015 and found out the following difference: when the second party responds to NEGOTIATE request with 405 Method Not Allowed Lync Server 2013 or 2015 resends NEGOTIATE requests once again, the second party respondes with 405 Method Not Allowed again and after that Lync Server starts sending INVITE and other requests. So we can call. But with Lync Server 2010 such mechanism doesn't work.

    Hope you can help and explain how we can call using Lync Server 2010 to the second party. Maybe there is a way to disable NEGOTIATE compression requirement on Lync 2010. Please suggest.

    Thanks in advance!

    Friday, March 17, 2017 11:35 AM

Answers

  • Hi Jayakumar 

    Thanks for your reply. But my question was releated to NEGOTIATE process only not to "INVITE stage".

    Actually, I've resolved unpredictible behaviour described above. By default Lync Server 2010 side uses TLS 1.0 and after switching it to TLS 1.2 it finally works like Lync Server 2013 and Lync Server 2015.


    • Marked as answer by serzubov Friday, March 17, 2017 1:43 PM
    Friday, March 17, 2017 1:42 PM

All replies

  • Below article explaining your scenario.The second invite will be with the media path and candidate selection confirmation.

    https://digitalbamboo.wordpress.com/2013/08/17/lync-media-conferencingaudio-call-flow-of-sip-and-sdp/

    https://ucgeek.co/2014/02/understanding-how-lync-establishes/


    Jayakumar K

    Friday, March 17, 2017 1:32 PM
  • Hi Jayakumar 

    Thanks for your reply. But my question was releated to NEGOTIATE process only not to "INVITE stage".

    Actually, I've resolved unpredictible behaviour described above. By default Lync Server 2010 side uses TLS 1.0 and after switching it to TLS 1.2 it finally works like Lync Server 2013 and Lync Server 2015.


    • Marked as answer by serzubov Friday, March 17, 2017 1:43 PM
    Friday, March 17, 2017 1:42 PM
  • Hi serzubov,

    Thanks for your sharing, it will help others who have the similar issue.


    Regards,

    Alice Wang


    Please remember to mark the replies as answers if they help.
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    Monday, March 20, 2017 1:51 AM