[Home](./index.md) > [sip.js](./sip.js.md) > [Transport](./sip.js.transport.md) ## Transport interface Transport layer interface expected by the user agent core. Signature: ```typescript export interface Transport ``` ## Remarks The transport layer is responsible for the actual transmission of requests and responses over network transports. This includes determination of the connection to use for a request or response in the case of connection-oriented transports. https://tools.ietf.org/html/rfc3261\#section-18 ## Properties | Property | Type | Description | | --- | --- | --- | | [protocol](./sip.js.transport.protocol.md) | string | The transport protocol. | ## Methods | Method | Description | | --- | --- | | [send(message)](./sip.js.transport.send.md) | Send a message. |