SIP Trunk Requirements NAT and Public Static IP

[petewatterschats]

My impression from reading entries in this Form is that some are using Dynamic Public IP addresses which implies that they are using port Forwarding on their Router giving access to the Internet. They are also using a DDNS service like DynDNS to insure that the Public FQDN always resolves to the Public Address of the WAN port on their router

3CX in their training materials and documentation says that you need a Static NAT and Static Public IP Address where the cost for the Internet service is significantly higher.

This issue is for small business and Home Use where costs are a factor but what is the down side or will not having a Static IP and NAT even be possible

 

[leejor]

3CX version 12.5 isn't quite as picky in the install instructions about the use of a dynamic IP. If there is enough of a push-back, then the requirement (wording) might change for version 14. I believe, at this time, it says that some features not work properly.

some are using Dynamic Public IP addresses which implies that they are using port Forwarding on their Router

may

The use of port forwarding does not imply this. It is required in either case.

 

[petewatterschats]

To me "Static NAT" means that you map a public address directly to a private address. Then in the firewall you open ports for this mapping.

 

[leejor]

To me "Static NAT" means that you map a public address directly to a private address. Then in the firewall you open ports for this mapping.

If you read the definition here...

http://www.bayt.com/en/specialties/q/11 ... c-nat-pat/

Are you planning to to map one public IP to one local IP?

Everyone is going to have different set-ups. You can use a router, that is shared with other devices on a network, most common for a set-up where there is only one high speed connection available, and, it is shared. In this case the public IP, as a whole would not be "mapped" to only one private IP. You would use the routers port forwarding to "send" only certain ports to the device running 3CX. All other ports would only be used if other devices required them. You may choose to not use a firewall but let the router "protect" you network. You could have the 3CX server not even use a private IP, but instead a public IP, then make use of a firewall to allow only the ports required to reach the server. Many cloud deployments will be set-up this way.

You could use a router and a firewall, there are many variables depending on the situation and security concerns.

In answer to your original question about DDNS... check the recent post from Nick, here.

a-couple-of-questions-about-internal-and-external-fqdn-43393-s15.html