One of the most frequently asked questions concerns the possibility of remotely accessing IP devices connected to a home and / or company network via the Internet. Let's say that remotely accessing any device connected to the local network implies some "smattering" on the operation and configuration of networks as well as on the setting of the router and other networking devices.
Static / Dynamic IP
The address Static IP is an address that is definitively assigned by internationally recognized authorities and uniquely identifies your connection. Normally, the ISP (Internet Service Provider) telecommunications operator assigns a temporary IP address to the modem router which is valid for the connection time (Dynamic IP). The temporary assignment allows you to recycle the address between users, if the connection is interrupted (eg the router is switched off) the address can be assigned to another user.
Public / Private IP
THEPublic IP (Both static and dynamic) is an address reachable from anywhere else on the Internet (Typically, you can ping it). A dynamic public IP can be reached via URL using Dynamic DNS services (Topic). Since static public IP addresses have a price and to overcome the scarcity of the same, the ISP usually assigns an address Private IP of your network from which you can reach the Internet but the reverse is not possible (Cannot ping it). Other times, even if the IP is public, the ISP blocks access from the Internet for security reasons.
NAT / Firewall
The modem router with which your LAN is connected to the Internet has NAT / firewall functionality, this means that by default the incoming ports are all closed so access to the LAN from the Internet is disabled.
Access from the Internet
So to reach from the Internet a device connected to your LAN network that will have a private static IP inside your LAN you need an Internet connection with a public IP (Static or dynamic), and you will have to open access ports on your router by creating NAT (or Port forwarding) rules between the Internet and your LAN. As is evident, this solution involves settings on the router connecting to the ISP, which are often not possible as the router is blocked by the ISP itself or in the case of corporate networks it is the same corporate IT manager who prevents its configuration for reasons safety. So many prefer to use a standalone internet connection (via a cellular router) for remote access to the device to be controlled.
But even in the case of autonomous connection with a cellular router, the problems are not over, the mobile ISP will assign you a dynamic IP, many times private, on which access from the Internet is blocked for security, so in order to access you will have to ask the 'ISP unlocking the doors (Topic). When the IP is unlocked, you will need to configure the NAT rules in the router for each device / port you want to access remotely. And every time you connect a new device to your LAN to access it, you will first have to configure its NAT rules.
VPN (Virtual Private Network)
A VPN (See article) is a private telecommunications network, established between subjects that use, as a transport technology, a public and shared transmission protocol, such as the Internet. A VPN can be seen as the geographic extension of a corporate private local network (As if your network cable extends geographically), the cellular routers distributed by us can create VPN (Topic). It is evident that all the devices connected in VPN are correctly reachable with their IP address, but are not reachable by Internet connections outside the VPN.
EasyAccess
You will surely have used a program like SKYPE or WhatsApp to communicate or TeamViewer for remote desktop without asking for the IP address of your interlocutor. THE Weintek operator terminals they integrate EasyAccess which allows you to access your operator terminal from anywhere in the world, an easy-to-use service such as an instant messaging service. You will not need to know the IP address of the operator terminal or spend hours configuring your router or configuring complex port mappings. EasyAccess solves all these problems and provides a complete solution to access your remote operator terminal. But not just through the pass-through procedure (Topic) you can reach any IP device on the terminal's network, and if you don't need the screen you can use the CMT-SVR.
Logging
So far we have seen how to remotely access devices, but if the need is to receive data from remote devices via the Internet, there are much simpler solutions that use our devices. SlimLine. In all these applications is the system that opens the TCP connection so they can operate on any type of connection with private, public, dynamic IP and without having to intervene on the configuration of the router.
The system can collect data and send it to a server in the cloud using the REST protocol, can send data to a broker using the MQTT protocol, can create a file (CSV format) in its file system and send it automatically to a remote FTP server (Topic). More systems SlimLine they can talk to each other exchanging data (See article), or connect to each other in Client / Server mode and then with the FB DataStreamExch open a communication channel with another IP device on the LAN.