SPDY Protocol

Why Trust Techopedia

What Does SPDY Protocol Mean?

The SPDY (pronounced speedy) protocol is an open-source, Transmission Control Protocol (TCP)-based, application layer protocol that transports content over the Web. Developed as an experimental protocol by Google’s Chromium group in 2009, SPDY is primarily geared toward reducing Web page latency.

Advertisements

Techopedia Explains SPDY Protocol

The Chromium project was initiated to achieve higher transmission speeds by rendering a single connection per client to prioritize and multiplex the file transmission process. The SPDY protocol is made up of a session layer on top of a secure shell (SSL), which facilitates multiple concurrent and interleaved streams over a TCP connection. SPDY defines a new framing format for encoding and transmitting data over the wire.

SPDY protocol features include:

  • Server-initiated streams: SPDY facilitates content delivery to the client without a client request through an advanced server-initiated stream feature. Two different configuration options are available: Server push and server hint.
  • Multiplexed concurrent streams: SPDY facilitates unlimited concurrent streams across a single TCP connection.
  • Request prioritization: SPDY request priorities overcome clogging problems by assigning priority tags to each request, which allows unlimited client content requests.
  • Compression: SPDY compresses request and response HTTP headers, facilitating the transmission of fewer packets and bytes.

Google’s Chrome browser uses SPDY while communicating with Google services, such as Gmail, Google Search, Chrome Sync and Google ads.

Advertisements

Related Terms

Margaret Rouse
Technology Expert
Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.