Well, I thought I could start a thread about that. I am trying to accomplish this, and I guess I am not the only one. Lync 2010 seems to have quite some success (compared to OCS), so there are probably business opportunities around this. My first attempt is a half success, as I got calls from Lync to FreeSWITCH working (need some extensive testing, though), and calls from FreeSWITCH to Lync are connecting ok, but they get disconnected after circa 30 seconds. I am trying to pinpoint the reason for this disconnection, but untll now, I had no luck. RTCP requirement was disabled on the Lync side (RTCPActiveCalls), but anyway I have enabled RTCP on the FreeSWITCH, so it should not be that. RTP is flowing normally, it's not a call on hold or muted. Refer was disabled on the Lync side. SessionTimer is enabled on the Lync side (but I dont think I ever saw a REINVITE caused by the session timer). I just suddenly receive a BYE from Lync, after 30-35 seconds. On the Lync side, as you can guess, it's not easy to access any meaningful logs. I think our partner managing the Lync will have to escalate that to the SVP Product Engineering to get the right command to enable the interesting debug mode :) I've been told that some folks at MS were claiming a such trunking was not possible. Well, I would tend to say otherwise, as I am not far to get this working, except of course if they just hardcoded some forbidden Owner Usernames in the SDP, like FreeSWITCH, in order to save this business from the mean OpenSource world and leave it to commercial SBC vendors. I can hardly imagine they would dare to do that in 2011, so the question remains opened: what may be closing that call after 30 seconds ? I would be glad to discuss the subject, here or privately, with anyone who is involved on a such project, or planning to be soon. David Ponzone Direction Technique email: david.ponzone@ipeva.fr tel: 01 74 03 18 97 gsm: 06 66 98 76 34 Service Client IPeva tel: 0811 46 26 26 www.ipeva.fr - www.ipeva-studio.com Ce message et toutes les pièces jointes sont confidentiels et établis à l'intention exclusive de ses destinataires. Toute utilisation ou diffusion non autorisée est interdite. Tout message électronique est susceptible d'altération. IPeva décline toute responsabilité au titre de ce message s'il a été altéré, déformé ou falsifié. Si vous n'êtes pas destinataire de ce message, merci de le détruire immédiatement et d'avertir l'expéditeur.