[Home](./index.md) > [sip.js](./sip.js.md) > [UserAgent](./sip.js.useragent.md) > [start](./sip.js.useragent.start.md) ## UserAgent.start() method Start the user agent. Signature: ```typescript start(): Promise; ``` Returns: `Promise` ## Remarks Resolves if transport connects, otherwise rejects. ## Example ```ts userAgent.start() .then(() => { // userAgent.isConnected() === true }) .catch((error: Error) => { // userAgent.isConnected() === false }); ```