So what’s the problem?

We’re making more and more use of our Internet connections; even the apps that used to exist on our local network are now located in ‘the cloud’ somewhere, whether Private, Public or a combination thereof. The problem is that our connection to the Internet hasn’t grown nearly as far as our usage. This poses a real problem for businesses who want to make use of the latest and greatest applications and online services.

WAN optimization has been the subject of extensive academic research almost since the advent of the WAN[4]. In the early 2000s, research in both the private and public sectors turned to improving the end-to-end throughput of TCP[5], and the target of the first proprietary WAN optimization solutions was the Branch WAN. In recent years, however, the rapid growth of digital data, and the concomitant needs to store and protect it, has presented a need for DC2DC WAN optimization.

Component techniques of Branch WAN Optimization include deduplication, WAFS, CIFS proxy, HTTPS Proxy, media multicasting, Web caching, and bandwidth management. Requirements for DC2DC WAN Optimization also center around deduplication and TCP acceleration, however these must occur in the context of multi-gigabit data transfer rates.

So how do we fix it?

Well, you could simply upgrade your Internet connection but that is unlikely to give you the result you need and it will certainly hurt your pocket. Simply throwing more bandwidth at a poorly performing application doesn’t necessarily fix the problem and comes with several pitfalls:

• It will be significantly more expensive than deploying a WAN Optimisation solution.
• It is a ‘one fix’ solution focussed on bandwidth with no other benefits.
• New connectivity usually means long lead times, new hardware and IP addressing.

What should you do? You guessed it! You should deploy a WAN optimisation solution. Not just because we say so, but because it brings real business benefits. WAN Optimisation provides many more benefits than just fixing bandwidth issues:

• Take data ‘off the wire’, that means less ‘actual’ bandwidth is required in the first place.
• Fix poorly written applications, which more bandwidth just won’t cure.
• Increase employee productivity (yes we said it) simply by making things happen 'faster'.

CIFS (Server Message Block) servers make their file systems and other resources available to clients on the network. Client computers may want access to the shared file systems and printers on the server, and in this primary functionality SMB has become best-known and most heavily used. However, the SMB file-server aspect would count for little without the NT domains suite of protocols, which provide NT-style domain-based authentication at the very least. Almost all implementations of SMB servers use NT Domain authentication to validate user-access to resources.

Give me the deep-dive...

Our WAN Optimisation feature-set can be split into 3 key areas of functionality, Data Deduplication, Data Compression and Application Optimisation. Usually all 3 of these highly sophisticated techniques are applied to your traffic as they flow through your Xrio device to the Internet or remote site.

Data Deduplication

Take this scenario: You’ve just completed your shiny new 50mb PowerPoint presentation and sent it over to your regional manager at head office. He loves it, but wants to change the font from your corporate font to Comic Sans, he promptly sends it back, noting how great you both are. No real problem there right? Wrong.

When the manager sent the file back, nothing really changed but the whole file was still sent over the Wide Area Network - not exactly the most efficient use of bandwidth. The reason we care is that this bandwidth is precious, as we know that getting more of it is expensive and we need this precious bandwidth for more important applications like voice and video.

How do we improve this situation?

The first time the file was sent we took a copy (cache) of the individual blocks of data that make up the file. Once the file arrives at the remote site we take another copy before sending it onto its intended destination. Now, here is the clever part. When the manager sent the file back we analysed what was being sent and found that the file looked mostly the same. Therefore the Xrio appliance at the head office simply told the appliance at the remote office to ‘replay’ the file from its memory and sent over the wire ONLY the parts that had changed. Not only did you receive the changed file in a fraction of the time, the WAN connection was left free for those important applications.

Application Acceleration

Some applications were just never designed to work over a Wide Area Network, such as Windows File Sharing, and some applications were just poorly designed sending too much unnecessary data backwards and forwards.

How do we improve this situation?

We’ve analysed a bunch of commonly used protocol’s, identified where they are inefficient and applied some magic. This magic essentially means that data which doesn’t need to be sent is never sent. A common example is something we call "network chatter" - that is when the client computer and the server continuously send messages to each other to verify connectivity. These 'chatty' applications not only use up valuable bandwidth but generally function poorly because of increased latency between the client and server.

Data Compression

Compressing files using techniques such as zip have been used since the early days of computing. The process of taking a file or multiple files and making them smaller is used to great effect in today’s modern digital world. It turns out the same concept can be applied to blocks of data as they pass through your Wide Area Network. Often the size of data can be drastically reduced by compression techniques enabling us to send fewer data packets in less time.