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speedy (SPDY)

The SPDY (Speedy) protocol was proposed by Google for accelerating web page invocation. Web pages are called by the request of the web client to the web server. The transmission of web pages from the web server to the web client is done using the Hypertext Transfer Protocol( HTTP) and the TCP protocol. Since HTTP protocol is not optimized for minimum latency, and web pages have changed a lot in the last decade, it forms a bottleneck in web page transmission.

Since web pages consist of multiple details such as text, graphics, or video, the web page details are each transmitted to the web browser over individual TCP connections. In addition, browsers support only a limited number of connections at a time. Both the multiple connection setup and the limited number of connections reduce latency.

The Google SPDY protocol, which stands for Speedy, relies on TCP/ IP, but is intended to replace the HTTP protocol. The speed increase is achieved by reducing overhead, interleaving the client's requests, and persistent connections.

As far as data reduction is concerned, header information is compressed, requests from the Web client are not transmitted sequentially but are interleaved in a multiplexing technique with interleaving, and as far as persistent connections are concerned, these are permanent and are not reestablished for each request. By these measures and by prioritizing the requests, the transmission of web pages to the web client is between 10% and 50% faster.

A similar approach is taken by HTTP 2.0, or HTTP/2, and the QUIC protocol, or Quick UDPInternet Connections (QUIC), which also achieves faster page loads. HTTP/2 compresses the HTTP header with HPACK and the QUIC protocol, which relies on the UDP protocol and removes the limitations of the SPDY protocol due to the underlying TCP protocol.

Englisch: speedy - SPDY
Updated at: 05.08.2016
#Words: 292
Links: protocol, Google, web page, web client, server
Translations: DE

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