Hi, We have the weirdest problem here: Some of our numbers can not be called, outgoing works fine. The server doesn't get the invite (so nothing is logged). Other numbers on the same account do work. The Invite is sent from the provider, as I can see the tcp packet arriving on the server PC (using a packet sniffer). Reboot server pc -> doesn't help, Restore config -> doesn't help Changing the destination of an incoming (DID) number (fi, from internal 401 nr togroup all) and back does solve the problem for a few hours. Help!!! config : Windows Vista Home Premium 3GB mem CD E2220 CPU Symantec endpoint security with all traffic allowed on voip ip-adressses, local lan, and all communication from/to 3cx executables allowed.