Forward public IP to a lan IP

[telecomtekperson]

I have a dsl modem with a wan IP. I want to set up a VOIP phone with the office. I need to forward a public IP to the internal phone system (192,168.1.2). I have searched linksys, and this forum, but not getting it. Please help.

 

[smah]

Do you know what port(s) the VOIP phone operates on? I know very little about VOIP, so my question is: If you were to plug this phone into the broadband modem (without the linksys device), would it just work (with the public IP address), or is there something more involved?

 

[telecomtekperson]

There are a bunch. I have some that need to go to an ftp server (192.168.1.20) and a some that go to the phone system.

I thought I would be able to forward one of my public IP's to the lan IP and that would be the end of it...???

 

[smah]

So you have multiple public IP addresses? - One of which you want to use exclusively for the phone?

If the above is correct, think about this:
Put a switch in front of the linksys router (internet facing). The linksys router will get/use the same public IP. Assign another public IP to the phone (however you do that). All ports for the phone's public IP address will go to the phone. Now, not being knowledgable about these phones, I strongly suggest that you research the security ramifications of having them directly connected to the internet. I imagine that that would be fine, but what do I know.