Spacenet Internet Page Accelerator™ Technology
Spacenet is the leader in accelerating web browsing over VSAT through its patented Internet Page Acceleration (IPA) technology. Spacenet’s IPA intelligently “pre-fetches” images and other objects to effectively defeat the latency inherent in all satellite networks.
Spacenet IPA requires no software to be installed on the user’s computer, and works with all operating systems and all modern web browsers (those that are able to use web proxies). The only configuration needed is to select the remote user’s VSAT IP address as their web proxy server; the rest of the process is entirely transparent to the user.
A typical HTTP exchange involves a request by the browser for a web page and a response from the web server, which contains the HTML text of the requested page. The HTML page also contains requests for "objects," such as images, embedded media or scripts, each of which must be retrieved with a separate HTTP request and response. The problem with this approach is that it requires an extended series of back-and-forth communications between the browser and Web server, which is less than ideal for satellite.
When a user on an IPA-enabled network requests a web page, their browser sends a HTTP "GET" request to their web proxy (their local VSAT IDU), which is then forwarded to the destination web server. The web server sends an HTTP response that includes the page’s base HTML text file. The IPA software at Spacenet’s hub facility intercepts this response and immediately initiates the HTTP "acceleration" exchange process for the remaining elements of the web page.
This exchange takes place using a high-speed, low-latency terrestrial connection between the hub and the Internet, saving the time that each request would have needed for a round trip over the satellite link. As the contents of the web page are retrieved by the hub facility, they are then immediately forwarded to the remote browser over the satellite link.
The user’s browser receives the HTML document and the pre-fetched page objects in rapid, uninterrupted succession. As each element is received, the browser generates the appropriate "GET" requests to obtain the remaining elements. However, since these requests have already been made at the hub, and are already in process, the IPA software on the VSAT web proxy simply terminates these requests without sending them up to the satellite. The net result is that only a single "GET" request must traverse the satellite link, and a series of rapid responses quickly deliver the requested web page to the browser.
The IPA user experience is a brief pause after requesting the web page (the half-second delay required for data to make a complete round-trip across the satellite and into the Internet), followed by near-instantaneous delivery of all content residing on the page requested. Additionally, because IPA reduces upstream satellite traffic, it can also lead to a reduced need for satellite capacity, the most costly element of a satellite network.
|
