We have a CS-1000m on rls.7.0 that also has some IP sets going to a remote building in it . The conference has seemed to stop working on these sets . You call your first party they answer then hit the conference key and call your second party and they answer ,when you try to connect them by hitting the conf.key again nothing happens. This happens no matter what combination you try all internal, 2 outside one inside, etc. The sets are on firmware C8A. Like I said they did work before we know of nothing they may of changed . Also on VOIP sets where does the conference take place MGC?