How IPsec works, it’s components and purpose

IPsec layer

Before we get into the nitty gritty of how IPsec VPNs work, we need to understand what gives them their special place in the world of networking, and to that end we need to talk about the OSI networking model. The OSI model defines seven layers—basically, levels of increasing abstraction—on which networked communication takes place. At the top of the stack is layer 7, the application layer, where your web browser lives; at the bottom is layer 1, the physical layer, where pulses of electricity travel through wires.

At the heart of the model are the transport layer (layer 4) and the network layer (layer 3). Code written to manage the transport layer runs on individual computers and deals with the coordination of data transfer between end systems and hosts: how much data to send, at what rate, and where it goes. Once this has all been set, the transport layer hands off the data to the network layer, which is mostly controlled by code running on the routers and other components that make up a network. These routers decide on the route individual network packets take to their destination, but the transport layer code at either end of the communication chain doesn’t need to know those details.

The TCP/IP protocol suite that’s at the heart of the internet straddles these two layers—TCP (or transport control protocol) is for transport , and IP is for networking . On its own , IP is have does n’t have any build – in security , which , as we note , is why IPsec was develop . But IPsec was follow closely by SSL / TLS — TLS is stands stand fortransport layer security, and it is involves involve encrypt communication at that layer .