WebSocket

Abstract: Internet communication provides a convenient, hyperlinked, stateless exchange of information, but can be problematic when real-time data exchange is needed. The WebSocket protocol reduces Internet communication overhead and provides efficient, stateful communication between Web servers and clients. To determine whether WebSocket communication is faster than HTTP polling, the authors built a Web application to measure the one-way transmission latency of sending real-time wind sensor data at a rate of 4 Hz. They implemented a Jetty servlet to upgrade an HTTP connection to a WebSocket connection. Here, they compare the WebSocket protocol latency to HTTP polling and long polling.

Abstract: A system enabling service communications in distributed Web applications between servers otherwise inaccessible due to cross-origin security restrictions in pre-HTML5 compliant Web-browser clients. A Web-browser client executes a client-side Web application received from a source origin server having a defined source origin and requests connections to request identified Web-application services. Execution of an emulation client library establishes a bidirectional capable HTTP-based communications connection between the Web-browser client and a gateway server, having a target origin outside the scope of the source origin, providing access to the request identified Web-application service. The bidirectional capable HTTP-based communications connection includes a cross-origin communications bridge providing a secure communications path between the source and target origins. The gateway server can establish an HTML5 compliant connection to a target defined service, provided by a target server, having a predefined relation to the request identified Web-application service.

Abstract: A gateway server interoperates with client and remote server systems to provide stateless security management for a distributed Web application. A Web client application on the client system initiates a WebSocket connection directed to a remote Web service by performing an authentication challenge directed to a user of the Web-browser client where a secure token is not present in a local store instance corresponding to the client application. The authentication challenge obtains the user credentials and then exchanges the user credentials with the gateway server for a secure token. The secure token is then sent in a protocol specific connect message to the gateway server. The gateway server, in response to receipt of the connect message, initiates a WebSocket connection directed to the remote Web service by inspecting the connect message to recover the secure token, evaluating the secure token to obtain user credentials, injecting the secure token with the user credentials, and sending the connect message to the remote Web service.

Abstract: An area of intensive research under the umbrella of the Internet of Things (IoT) has resulted in intensive proliferation of globally deployed sensor devices that provide a basis for the development of different use-case applications working with real-time data and demanding a rich user interface. Overcoming the lack of the standard HTML platform, HTML5 specifications WebSocket and Canvas graphics strongly supported the development of rich real-time applications. Such support has been offered by browser plug-ins such as Adobe Flash and Microsoft Silverlight for years. In order to provide a deep insight into IoT Web application performance, we implemented two test applications. In the first application, we measured latencies induced by different communication protocols and message encodings, as well as graphics rendering performance, while comparing the performance of different Web platform implementations. In the second application, we compared Web performance of IoT messaging protocols such as MQTT, AMQP, XMPP, and DDS by measuring the latency of sensor data message delivery and the message throughput rate. Our tests have shown that although Adobe Flash has the best performance at the moment, HTML5 platform is also very capable of running real-time IoT Web applications, whereas Microsoft Silverlight is noticeably behind both platforms. On the other hand, MQTT is the most appropriate messaging protocol for a wide set of IoT Web applications. However, IoT application developers should be aware of certain MQTT message broker implementation shortcomings that could prevent the usage of this protocol.