Users at a remote branch connected via wan to centralized ccm 4.1.3ess122.1 cluster are randomly having transferred calls getting a fast busy. The same is happening with call park. What appears to be happening is that when the call gets to the point when it should ring to Unity it instead is getting a fast busy. Site is set up to use g.711 codec to unity and when watching the audio stat and call viewer tools I can see that indeed we are using g.711. I have had multiple tac cases open and they just keep asking for debugs and traces but not giving me any resolutions. Has anyone seen this before? The phones are 7961's and 7941's. Routers are 3825's, there are three dms-100 pri's at the site. Any advice on where to look would be greatly appreciated.