class in UnityEngine.NetworkingSwitch to Manual
A High level network connection. This is used for connections from client-to-server and for connection from server-to-client.
A NetworkConnection corresponds to a specific connection for a host in the transport layer. It has a connectionId that is assigned by the transport layer and passed to the Initialize function.
A NetworkClient has one NetworkConnection. A NetworkServerSimple manages multiple NetworkConnections. The NetworkServer has multiple "remote" connections and a "local" connection for the local client.
The NetworkConnection class provides message sending and handling facilities. For sending data over a network, there are methods to send message objects, byte arrays, and NetworkWriter objects. To handle data arriving from the network, handler functions can be registered for message Ids, byte arrays can be processed by HandleBytes(), and NetworkReader object can be processed by HandleReader().
NetworkConnection objects also act as observers for networked objects. When a connection is an observer of a networked object with a NetworkIdentity, then the object will be visible to corresponding client for the connection, and incremental state changes will be sent to the client.
NetworkConnection objects can "own" networked game objects. Owned objects will be destroyed on the server by default when the connection is destroyed. A connection owns the player objects created by its client, and other objects with client-authority assigned to the corresponding client.
There are many virtual functions on NetworkConnection that allow its behaviour to be customized. NetworkClient and NetworkServer can both be made to instantiate custom classes derived from NetworkConnection by setting their networkConnectionClass member variable.