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Could somebody clear this up for me (I've seem to forgotten it): I know you can run a HTTP and SPDY "versions" of your webpage in parallel. But how does the bro
by CWIZO 14y ago
Could somebody clear this up for me (I've seem to forgotten it): I know you can run a HTTP and SPDY "versions" of your webpage in parallel. But how does the browser know which protocol to use (if it supports both)? Does it initially make a HTTP request and the server responds with some header that let's it know it can use SPDY or what?
- zxoq 14y agoThe server tells the client it can handle SPDY through an Alternate-Protocol header. The client then makes subsequent requests over SPDY. http://dev.chromium.org/spdy/spdy-protocol/spdy-protocol-draft2#TOC-Server-Advertisement-of-SPDY-through-the-HTTP-Alternate-Protocol-header http://dev.chromium.org/spdy/spdy-protocol/spdy-protocol-dra...
- CWIZO 14y agoOK thanks. That cleared things up :) Too bad that this means that the first request (which is usually the most expensive one) is always done trough HTTP :/
- laktek 14y agoNot really. The HTTPS requests can choose SPDY using the Next-Protocol-Negotiation(NPN). Alternate protocol header would matter only to HTTP requests to know this server is capable of supporting SPDY. However, as per the latest post by Opera Labs[1], all 3 major browsers supporting SPDY doesn't handles this header correctly. Also, it's not mentioned in SPDY draft 3. [1] http://dev.opera.com/articles/view/opera-spdy-build/ http://dev.opera.com/articles/view/opera-spdy-build/