I have a sip provider that has no registration in the trunk by username and password and the fields should remain empty.
Question 1: can I create a trunk to them without username and password?
In order to secure the trunk, the SIP provider would like to know what IP address will be used.
Question 2: what is the IP address for pbxes? Should I look up and give them the ip address for pbxes.org or pbxes.com or www3.pbxes.com ?
Once you allow traffic from pbxes.prg, I will be able to use your account, since it does not require a username or password. If you feel like throwing away money, please let me know.
If your provider gave you a tech prefix which is unique to you, then you are ok. Otherwise you can't use those provider who just do pure sip trunking.
You gotta have a unique public ip address, which you don't have here on pbxes.org