Devices with a data+ SIM card are assigned a private IP address. This is private and dynamic by default.
If a data+ SIM card is delivered with the standard APN "wsim", then a dynamic private IP is assigned to the device with this SIM. Devices using this APN cannot reach each other.
A data+ SIM card delivered with the APN "wsim.link" assigns a static, private IP to the device. IPs can reach each other. For technical reasons, the IPs are not assigned consecutively.
If a data+ SIM card is delivered with the APN "pip", then a static, public IP is assigned to the device. This can be reached via the Internet. A public IP address is associated with additional costs.
Explanation of the terminology
Private IP: The IP cannot be reached from the Internet, but only via a VPN tunnel (IPsec) or in the case of the "wsim.link" APN via other devices (devices can reach each other). In order for devices with a private IP address to access the Internet, they are assigned a public IP via carrier-grade NAT (Network Address Translation). This public IP address is used by several devices at the same time and the data traffic is assigned internally via port assignments to the corresponding SIM card. As a result, this IP is not suitable for accessing the device via the Internet.
Public IP: The public IP can be accessed from the Internet. Therefore, special security mechanisms are required on the device to prevent unauthorised access to the device.
Static IP: The IP address is constant and does not change. This means that the device can always be reached via the same IP address.
Dynamic IP: The IP address can change regularly, for example when re-establishing a data connection. This means that access to a device is only possible if the last assigned IP address from the online portal is used.