ZeroTier, Inc. is a software company with a freemium business model based in Irvine, California.
ZeroTier provides proprietary software, SDKs[1] and commercial products and services to create and manage virtual software-defined networks.
[3][4][5] ZeroTier markets proprietary tools, which are licensed under a Business Source License 1.1,[7] intended to support the development and deployment of virtual data centers: In 2021, the product line consists of the following tools: The ZeroTier client is used to connect to virtual networks previously created in the ZeroTier Central web-based UI.
STUN and hole punching are used to establish direct connections between peers behind NAT.
Direct connection route discovery is made with the help of a global network of root servers via a mechanism similar to ICE in WebRTC.