might help clarify your current problem, if you are working in a static and protected network then your working settings are fine, neither of your boxes “require” authentification, but if you want to use SIP invite authentication, then you will need to choose a scheme that is acceptable to both and use the correct credentials (which you will presumably have previously set up). You can debug the SIP conversations on both ends to find out what you have wrong common problems are obvoiusly wrong account/passwords and less obviously attempting to use digest authentification without having previously set it up completely, if in doubt, try google.
I’m not sure if the Username or remotesecret are the correct thing to be using however the username and password values are correct.
when we send an INVITE to the opensips (from freepbx) we get a 407
with this field
Proxy-Authenticate: Digest realm=“192.168.168.183”, nonce=“52ef9bda000000431f0208e68c83258ad2b6510af66d8f78”
and I still get a 403 response back I feel that freepbx . I read somewhere that you can configure how the md5 hashes the username and password but I don’t know how you are meant to format that part.
If you want to use digest authentication with asterisk you will need to learn how it works, I could tell you but what fun would that be and how would you have increased your feeling of security?