The problem is in the call forward.Extension 6000 is configured to forward all calls to extension 7000. When someone call 33336000 (PSTN H323GW site A) and the call try to forward to 7000 (Voip H323GW Site B) it come a busy tone. With the same configuration when I call the extension 6000 (SiteA) from extension 8000 (Voip H323GW Site C) the call is normally forwarded to 7000 (siteB). I'm using CUCM 6.0.
I will appreciate any help.