Let us begin by learning about VPN.
VPN stands for the virtual private network. It is an encrypted connection over the web from a device to a network. The encrypted connection supports that sensitive information is safely communicated. It avoids an unauthorized person from eavesdropping on the traffic and enables the user to organize work remotely. VPN technology is broadly used in corporate environments.
A VPN protects your IP address by allowing the network to redirect it through a particularly configured remote server run by a VPN host. This defines that if you surf online with a VPN, the VPN server becomes the source of your information. This defines that your Internet Service Provider (ISP) and other third parties cannot view which websites you inspect or what data you send and receive online. A VPN works like a filter that shifts all your information into "gibberish".
A remote-access VPN is invented to connect remote users securely to a corporate network. For example, when the COVID-19 pandemic arrived in 2020, some organizations transitioned to a remote workforce, and established secure remote access VPNs from the remote users to attach to critical business services at the corporate site.
VPN as a Service or a cloud VPN is a VPN hosted in a cloud-based infrastructure where packets from the user introduce the web from that cloud infrastructure rather than the client’s local address. Consumer VPNs generally use this model, allowing users to secure themselves while linking to the Internet via insecure public Wi-Fi and offer some anonymity while accessing the Internet.
APN stands for Access Point Name. It is the name of a gateway that can include devices such as protocol translators, rate converters, signal translators, etc. It can support a system capable of being regulated reciprocally among a GPRS that is a mobile data service on the 2G or 3G mobile network and another computer network, generally the public Internet. It can preserve confidential data being sent over a public telecommunications network. It can be used in creating the packet data network, most generally used over the 2G or 3G networks.
A mobile operator needs to support data or internet services to its subscribers. The operator is required to set up a gateway node (GGSN-3G/PGW-4G) in-home network. APN is the address of the gateway node to acquire data functions while roaming.
When a subscriber roams, it connects to the home network for mobile services (voice, SMS, and data) via a roaming network. For accessing data service, SGSN in the roaming data and for setting up a PDP context to access the internet.