Detail this asset from Unity Store: Original Link
This is a paid asset, but now you can download Storm Unity Networking Free.
Storm Unity Networking v1.1
Storm Unity Networking is a fast, simple and flexible networking solution for server-client multiplayer games.
Storm hides you from the complexity of the using sockets, allows to use high-level API as remote procedure calls and synced variables, but it still stays fast.
Storm supports both: TCP and reliable UDP sockets.
Asset includes a detailed documentation and a simple example.