Push Technology is the Core of the Real Time Web

Push technology is a term that is used often but rarely explained. Although we take it for granted, push technology hasn’t been around for long, and it had a false start at the very inception of the world wide web.

So what is Push technology exactly? It’s a method that allows a server to notify a client when an even occurs. What does this mean in real life?

A client is usually your computer or your cellphone. A server is a service you use, like E-mail or Twitter. The event is usually a new piece of content, like a new Tweet or a new E-mail.

What’s the opposite of Push technology? Yes, you guessed it, it’s called “Pull Technology” and its been the most common way of transferring content on the web. In a ‘Pull’ scenario, the computer or cellphone asks the server every so often if there’s any new content, and the server then tells the computer or cellphone if it does or if it doesn’t.

The most well known (and mostly used) type of Push technology is Microsoft Exchange. When you see a new email pop up on your computer’s Outlook or on your Blackberry, the Exchange server was the one that actually notified your computer or cellphone about it.

On the other hand, POP or IMAP emails are served only when the computer or cell phone request an update from those email servers.

If you think about it there are two immediate benefits for Push technology:

1. Push technology is immediate: if you are urgently waiting for an email and you are waiting between updates, you could miss important information because you will receive the email when your client checks the server and not when it is actually received.
2. Push technology is efficient: if you only received one email per day, you would only initiate one server connection during that day. In case of Push, if you are checking your email every 5 minutes, that means you initiated a server connection 12 times per hour or 288 times during that day.

In 1996, a revolutionary company was launched. Its name was Pointcast and basically it was a software application that users would download to get the latest information from their favorite sources, as well as financial information, all in real time. The technology behind it was revolutionary at the time. It pushed information to the thousands of computers that were connected to it, and it got an offer from News Corp. to the tune of $450 million dollars.

Unfortunately, users and IT departments started to complain that the software was causing major bottlenecks for the limited bandwidth at the time (everyone was using dialup) and the project died shortly after. It was replaced by a new kid on the block called ‘RSS‘, which is Pull technology and what is mostly used today by news sources and blogs.

There’s been a lot of talking about Push technology recently, thanks to the the iPhone’s ability to handle it with its new operating system, but also thanks to a new standard being implemented mainly by tech-centric applications like Twitter and FriendFeed. Instant messaging, E-mail and news updates would be really efficient using Push technology, and FriendFeed in particular has implemented a protocol called SUP, which allows users to receive updates from applications like Flickr the moment new photos are uploaded to the user’s account. There have been announcements of Push clients for GMail, Twitter and IM.

RSS was a great initial way to distribute content, but as more and more applications move to the real time web, Push technology will find its place at the core of all of them, and developers should start getting really involved in its implementation and extending the usage of common protocols to do so.

Photo by włodi

Tagged as: protocols, realtime, rss, sup