Hi there, As a newbie, I would like to get somebody addressing me o help me to find what is going on. any help is welcome. I have remote extensions (Cisco Linksys SPA92X and SPA94X) behind NAT connected to a Elastix v2.0. Inbound and outbound calls are working fine. Problem arise when I try Three-way call from SPA9XX units: I am able to make the first call, press conf button and stablish second call, but when I press conf button again, the first call continue in call waiting and MOH and never get access into the conference. Again, thanks for any help.