HTTP protocol
The Hyper-Text Transfer Protocol (HTTP) has become the most significant protocol used on the Internet and has expanded its role beyond web browsing with a large number of applications using HTTP for a variety of functions on both desktop and mobile devices.
AA provides the tools required by residential, mobile and business VPN service providers to accurately classify any web-based applications regardless of where the content is stored and how it is delivered. This is done by using either the default protocol signatures delivered with the AA ISA software or by defining string based signatures from the HTTP header information fields included in the HTTP request messages to further refine the detection.
HTTP session persistency
HTTP can use both non persistent connections and persistent connections. Non-persistent connection uses one TCP connection per HTTP request while persistent connection can reuse the same TCP connection for multiple HTTP request to the same server.
Nowadays most applications are using HTTP/1.1 and persistent connection but HTTP/1.0 and non-persistent connections remains on older software and mobile devices.
HTTP flows are classified in a particular application using the first HTTP request of the flow only by default. Optionally, the MS-ISA offers the flexibility to classify each HTTP request within the same flow independently using http-match-all-request feature.
HTTP proxy support
AA also supports traffic classification of HTTP between a subscriber and a web proxy. This feature is enabled by default, the ISA monitors and detects HTTP proxy flows automatically, each request within the same persistent connection to the proxy server is classified independently.