HI I installed a zyxel vdsl switch into a motel. The 200 has been running just fine. After all of the cross connects, modems installed into rooms, and everything is said and done. My internet works. My phone can receive calls on the extension and the DID. I can make extensions calls. But when I press 9 and make a phone call I get a busy signal. I have tried many numbers, they all ring busy. Any ideas??

check room status to see if its set for int loc
or ld

That's what it sounds like to me too

If you changed the type of trunks from "Dial In Tie" to "DID" in form 15 (by changing the "N" column???), they were deleted from the trunk group they were in.