I cannot get the PSTN line to register with 3CX I have a very basic setup in place, for testing and evaluation purposes: 3CX software running on Windows Server 2003 GrandStream 8-port GXW-400x gateway 1 GrandStream GXP2000 phoneset 2 Software phones The configuration is as follows: Extensions 100 and 102 are for the software phones Extension 101 is the GrandStream phoneset. ID and authentication work. I can call from set to set. When I try to make an outbound call, server status shows the following: 10:11:15.988 ServRegs:nAdd Registration is rejected: user <myuserID> is not in database 10:11:15.868 CallConf:nIncoming Incoming call from Ext.101 to sip:<thephonenumberI'mdialing>@192.168.1.56 LineStatus shows the line as unregistered when it is IDLE, and "RINGING" when I try to make an outbound call. If I make a call from another phone INTO this number, it rings busy. The gateway configuration is as follows: External Number <the pstn phone number> Internal Number 10000 Outbound Caller ID <the pstn phone number> Allow outbound calls on this line TRUE Answer incoming calls on this line TRUE Answer after 0 Authentication <ID> (using PSTN number as ID) Password <password> (Matching password) Route inbound calls in office hours to Extension 101 (the phoneset) Thanks for any help or info you can provide.