Overlayvõrgud

Overlay networks are a type of computer network that is built on top of another existing network, such as the internet. Instead of directly connecting devices, overlay networks use software to create virtual links between nodes. These virtual links can span across different physical networks, allowing for communication and resource sharing as if the nodes were directly connected.

The concept of overlay networks is fundamental to many modern internet technologies. For example, peer-to-peer (P2P) networks, which are used for file sharing and distributed computing, are a prime example of overlay networks. In a P2P system, each participant node acts as both a client and a server, contributing resources to the network and accessing resources from others, all within a virtual overlay.

Another significant application of overlay networks is in virtual private networks (VPNs). VPNs create a secure, encrypted tunnel over a public network, effectively forming an overlay that provides privacy and security for data transmission. This allows users to access private networks remotely as if they were physically present.

Distributed hash tables (DHTs) are also often implemented as overlay networks. DHTs provide a decentralized method for storing and retrieving data, distributing information across many nodes in a structured way without relying on a central server. This distributed nature makes them resilient and scalable.

Overlay networks offer several advantages, including increased flexibility, scalability, and the ability to implement custom routing or addressing schemes independent of the underlying physical infrastructure. However, they can also introduce complexities related to routing efficiency and performance due to the additional layers of indirection.