Friends, just a quick config question. I have a free standing box that I’m only using for web call back. When I try to use the feature, it appears to hair-pin back to my CISCO RV345P. The public-facing IP address that I’m using is: 192.0.2.42. I do have the IP set as up and pointing to a private ip, and as far as I know, the correct open ports are forwarded. But just want to confirm the correct PORT’s to open for this?
Howdy Friend! 
This is a friendly reminder to all y’all to please obfuscate your IP addresses, host and domain names, phone numbers, usernames, passwords, etc., before posting your info/logs to the forums and/or our FreePBX Pastebin. Although some times moderators will help make edits, it is up to you what you (initially) post. 
If you need ideas on example IP addresses, then please consider RFC 5737: IPv4 Address Blocks Reserved for Documentation. Similarly, the latest suggestions on example domain names are available in RFC 6761: Special-Use Domain Names.
Anyhow, to help answer your question, this appears to be a networking issue specific to your Cisco router. Those devices may or may not be able to manipulate the SIP headers to facilitate what you are trying to do. Some terms you’ll probably want to look for to find more details about VoiP routing functionality include Session Border Controller (SBC) and Application Layer Gateway (ALG).
Friends I have an WAN address pointing to a private IP which resolves to an installation of FREEPBX (for web call back). When I attempt to resolve the WAN address it just points to my firewall/router login screen so I don’t have the routing worked out correctly. I would like to know which ports I should be forward from the WAN to the private IP?
It is NAT, you choose.
This is going to be merged into your other post – please refrain from asking the same question twice in a less than 24 hour period.