SPDY: Protocol that will make web 2 times faster.

Its Google again, all set to make the web at least 2 times faster. SPDY (pronounced as SPeeDY) is the research project that it has taken up to make this happen. As Google puts it “SPDY is an application layer protocol for transporting content over the web, designed specifically for minimum latency.” In simple terms, it aims at making the interaction between browser and server faster.

It creates a session between the HTTP application layer and the TCP transport layer, above SSL (Secured Socket layer) and uses several techniques to make the interaction between browser and server faster:

• Multiplexed Streams: It permits multiple and concurrent streams over a single TCP connection, unlike HTTP. Streams are bi-directional flow of bytes across a virtual channel with in a SPDY session.
• Request Prioritization: Using this technique a client can request as many items as it wants from the server and assign a priority to each request.
• HTTP Header compression: SPDY compresses request and response header, which results in fewer packets and fewer bytes to be transmitted.
• A major enhancement to HTTP is server initiated streams, which is not found in HTTP. Server initiated streams enables the server to transfer content to the client, even when client does not make a request. This is done in two ways:

1. Server Push: Server pushes data to client via the X – Associated – Content header. This header informs the client that server is sending the information to the client before the client asked for it. This will remarkably increase the initial – page download speed.
2. Server Hint: Using X – Subresources header, server suggests the client that it should ask for certain resource. Server will wait to send the resource until the client asks for resource.

So far Google has developed a prototype SPDY enabled Google chrome browser and an open source web-server. After conducting a test by downloading top 25 web sites 10 times, it was found that the download speed increased by (up to) 55%. The browser and the web server have to be upgraded, where as no changes are required in web pages.

After testing under lab conditions, Google has a major task to make it work in real-life condition and make it compatible with other browsers like internet explorer, Firefox.