# start() Initiate some action to open the connection on the network like making a handshake, initiating a multiplexing session, etc. Starts the connection, which will cause the connection to evaluate its path, do resolution, and try to become ready (connected). `NetworkConnection` establishment is asynchronous. `onStateUpdate` will be called when the state changes. If the connection cannot be established, the state will transition to `waiting` with an associated error describing the reason. If an unrecoverable error is encountered, the state will transition to `failed` with an associated error value. If the connection is established, the state will transition to `ready`. ``` final func start() -> Self ``` ## Discussion Start should only be called once on a connection, and multiple calls to start will be ignored. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)