The Software Defined Network (SDN) has been one of those nebulous concepts that is coming someday to do something better than current IT technology. Well, that day has arrived and here’s what SDN is going to do for your company.
Why Software?Like software everything, the software defined network is intended to replace fixed hardware functions with reprogrammable software. It’s not really a simplification process. The hardware may be more generic, like microprocessors and digital signal processors, but if you include the lines of code, the component count shoots through the roof. The beauty of software is that all those “soft” parts can be replicated instantly at little or no cost. Even more importantly, software can be changed from afar as needed.
The Idea of Virtualization
You’ve probably run into virtualization in the IT racks. Not that long ago, a server was a stand-alone computer with its own operating system and software load. Each server had a designated function. If it was overloaded, you needed to buy a more powerful computer and swap out the boxes. If the application wasn’t that demanding, the server would loaf along most of the time.
In this type of environment everything needs to be planned up-front and changes are time consuming and sometimes expensive. There’s also a poor utilization of resources. You may need a lot of lightly loaded servers all cooking in the racks in order to run your myriad of business applications.
Virtualization changes all that. The server is no longer a hardware appliance but a software function running on one or more processors. The computer hardware might not look much different, but what used to be one server may now be a dozen running on the same box. Huge applications might span several boxes to get the job done. It’s just a matter of how much in the way of resources an application needs.
Some of what virtualization has accomplished is to reduce the number of physical computers needed since each box is running at a higher capacity. Even more important, a new virtualized server can be installed in minutes since it is simply a software “instance” running on the hardware already in the racks. Don’t need a server anymore? Simply have the software release the resources back into the pool. You don’t even have to set foot in the data center to make this all happen.
Does this sound like “The Cloud”? Virtualization on a huge scale is the magic behind cloud data centers and cloud services.
Virtualization for the WAN
Now consider your telecommunications network connections. Like all hardware based approaches, there are many specialized functions implemented by very specific equipment cards and boxes. Some are in the central office, some in the network path and some at the customers premises. It takes a long time to provision a new service and get everything wired up correctly so that you get the service you pay for and don’t interfere with others or have them interfere with you. The term “nailed up” goes back to the days when physical copper wires were literally nailed up on a board while they were assigned to a particular customer.
If you’ve ever tried to upgrade service, you know what a pain it can be. You need to submit a new order that needs to be processed. The changes to the network for your extra bandwidth have to be engineered. Then a truck has to roll to your location delivering a CPE (Customer Premises Equipment) box with the proper interface for the new service. Bandwidth is typically available in major increments and you better get your order placed well in advance of running out of current capacity.
Now, what if the network could be virtualized like the servers? The hardware becomes more of a life support system for the software. That software can be changed, upgraded or supplemented at will. All of a sudden, network changes become fast and easy. That’s the software defined network.
What AT&T is Doing in Austin
AT&T is launching its software defined network in Austin, Texas with the moniker AT&T Network on Demand. That’s pretty much what it’s all about. Businesses will be able to increase or decrease the bandwidth of their broadband speeds in near real time. In olden days (before SDN) this could take hours maybe days in the case of Ethernet services or weeks or longer for legacy SONET and T-Carrier.
The Carrier Ethernet services over copper and fiber that have appeared on the scene recently were engineered with more of the software defined network idea in place. One of their bragging points is that you can usually get a bandwidth increase by simply calling your service provider and making the request over the phone. No need to keep watching out the window for the service truck to roll in. As long as you have enough port capacity, the carrier will make the changes “invisibly” while you are doing other things.
In fact AT&T’s SDN will let them provision new communication ports in days compared to weeks. That’s an extension of the software-defined philosophy that separates physical hardware from software. Once again, as long as the installed hardware has the capability of handling the demands placed on it, what it does is really a function of software parameters and apps. Look for this approach to expand rapidly throughout the industry. It will be a matter of competitiveness among the communication carriers and other service providers.
Are you limited by your current MAN or WAN network capability? The service offerings are changing fast. Chances are that you can get more capacity and flexibility without a cost increase with MAN and WAN Network Services available now.
Note: Photo of Austin, Texas at night courtesy of Daniel Mayer on Wikimedia Commons.
