Web OS 10.0 Application Guide374 n Chapter 15: Content Intelligent Switching 212777-A, February 2002HTTP Header InspectionContent intelligent switching is performed by inspecting HTTP headers. HTTP headersinclude additional information about requests and responses. The HTTP 1.1 specificationdefines a total of 46 headers. For Web Cache Redirection, at any given time one HTTP headeris supported globally for the entire switch.HTTP headers can be general, request, response, or entity headers. General headers may existin both requests and responses. Requests and response headers are specific only to requests andresponses, respectively. Entity headers describe the content of the request body or the contentof the response body.Each HTTP header field consists of a name, followed immediately by a colon ( : ), a singlespace character, and the field value. Field names are case-insensitive. Header fields can beextended over multiple lines by preceding each extra line with at least one space.Some customer applications of HTTP header inspection are listed below: Redirection based on domain name Cachability based on domain name Virtual hosting Redirection based on browser type Cookie-based preferential redirectionBuffering Content with Multiple FramesTo handle the overall length of HTTP headers, including request headers containing multiplecookies, and the Maximum Segment Size (MSS) of dial-up connections, Web OS softwareprovides the following support: HTTP GET Request HeadersN OTE – In addition to the URL path, which generally is less than 300 bytes, the HTTP GETrequests also include general headers and request headers.o Parsing GET requests to match URL path and HTTP header beyond the first framewhile performing delayed bindingo Processing multiple frames from a single HTTP GET request, using a TCP stack onthe switch HTTP Cookie Request HeadersBuffering a maximum of 4500 bytes for a single GET request across multiple frames. Asingle GET request can include multiple cookies.
