Hello
jdi92,
First of all, it is wrong to not want a SBC, it is the first think you should want.
There are 3 options to seup an IP Phone on the 3CX Server:
A) Use of an SBC on remote site, to register the IP Phone.
B) Using an IP with 'Router' function (inbuild SBC).
C) The IP Phone will register as a 'flat' IP service (it seems, this is want you want to use)
To use this option you need make sure of the following options:
- Do the firewall test on the 3CX servere, it must be green and should be 100% good.
- The option "Block remote non-tunnel connections (Insecure!)", should not be set on the extension.
- Manually setup the IP Phone with SIP Details to register externally via the FQDN of the 3CX server.
The registration of an IP phone is as simple as just a few 'UDP' IP packets on the SIP port (default 5060 if not changed).
So again this should work, if not please check the SIP registration details you have used in the IP phone, there should not be anything else to do or check.
That said, it normally is 90% of the cases there is something wrong with the firewall.
Paulo