Performance evaluation of Websocket protocol for implementation of full-duplex web streams

Besides traditional synchronous HTTP request-response communication paradigm that was used on the Web for decades, modern Web services require more flexible communication system that enables asynchronous messaging between clients and servers, as well as server-initiated data delivery. Among several Web-based asynchronous communication paradigms emerged recently, the Websocket protocol and corresponding Websocket API are accepted as a pivotal framework for implementation of full-duplex asynchronous Web streams. In this paper, we evaluate the performance of the Websocket protocol with respect to underlying TCP protocol. We compare the two against the latency and amount of generated network traffic. The results show that, except a small overhead imposed due to initial handshaking, Websocket-based communication does not consume any more network traffic than plain TCP based communication. However, it is still slightly inferior in terms of latency.