Tech Chat | What is NAT-DDNS?

2022-09-20

In our last blog, we've talked about why we need to remotely manage the CORS station and how to reach it.

Apply for a static IP with high cost and policy limitation.
Use DDNS to automatically update the dynamic IP address.

However, the above two methods are based on the Extranet, which is the Internet. And both static IP and dynamic IP addresses are public IP addresses.

If we are using 4G instead of Ethernet, then the APN provider will assign a private IP address to your terminal device, which is under the large Intranet of the APN provider. In this case, how can we reach our device?

The answer is – NAT-DDNS technology.

You may be confused about these terms. Don't worry, we will explain in detail in this blog.

First, explain the concept of "Intranet" and "Extranet"

Intranet: That is, the local area network (LAN), such as the school's or company’s local area network, each local area network in each computer's IP address in the local area network has the opposite sex, is not repeatable.

Extranet: The Internet, which is also wide area network (WAN). The local area network is connected to the outside world through a server or a router. The IP address of this LAN is unique. All computers on the Intranet are connected to this extranet IP address and exchange data through this extranet IP address. The Intranet IP address of all computers in the same LAN is different, but they share the same extranet IP address.

What is NAT-DDNS?

NAT-DDNS (Network Address Translation- Dynamic Domain Name Server) is a Dynamic mapping method based on Dynamic Domain Name service (DDNS) and Network Address Translation (NAT). It is mainly to help users realize under the environment of network IP address can realize the dynamic DNS, keep real-time dynamic IP addresses and server communication, fixed binding domain, let Internet users input a specific domain name to access to a network host, can easily realize the remote management, remote configuration, remote check, etc.

Principle of NAT-DDNS

For Intranet devices, they can proactively access public network ports, but cannot be accessed by the public network. The main idea of NAT-DDNS is to take advantage of this. The node on the Intranet proactively accesses a server with a public IP address, and the intermediate server Bridges the server to open the tunnel from other hosts to the node behind the NAT.

How to use NAT-DDNS for CORS station?

Firstly, you should make sure whether your GNSS device supports NAT-DDNS. Here we take SV100 GNSS receiver as an example to show you how to use the NAT-DDNS.

Step1: Apply for the NAT-DDNS domain

There are some common NAT-DDNS service providers, such as