What to Look for in WAN Optimization
As enterprise wide area networks become taxed by ever-growing application traffic, many network managers have turned to WAN optimization and application delivery tools.
These products can improve the end-user experience and speed application delivery without increasing bandwidth requirements. What follows are some tips for selecting the right solution.
1. Think outside the box.
Selecting the right approach to accelerating a WAN can start with the checklists that vendors and analyst firms offer, but shouldn’t end there. Smart network managers should think outside the box — or quadrant — to build a holistic solution not bound by artificial lines drawn by marketing managers. Many products have added valuable features from different categories, and the right answer may come from a surprising angle.
2. Insist on decryption.
Applications of all types include Secure Sockets Layer–based encryption as a default, even within corporate networks. Security teams have been pushing for higher end-to-end security for decades, and application developers and system performance are finally catching up. Encryption, however, comes with a downside: There’s no good way to optimize, compress or cache information from a connection that is encrypted.
The common use of encryption means that network managers must configure WAN acceleration tools to decrypt the SSL traffic, do their particular magic and then re-encrypt, all without slowing anything down. WAN optimization won’t work with today’s applications without full-speed decryption. In addition to the obvious performance demands from all this encryption, SSL adds some management overhead. Organizations without a solid Private Key Infrastructure will need to add that implementation to their WAN optimization project.
3. Plan based on the latest data.
Networks have been getting bigger and bigger, both in the size of objects — such as files and e-mail messages — and in their link speed and bandwidth consumption. The growth is subtle, often nearly invisible, and definitely inevitable. Old assumptions about WAN performance, such as cache sizes and link speeds, may not be valid.
The use of AJAX in web applications is as widespread as it is disruptive. When Google uses AJAX to suggest query results while the user types on a search page, that’s a powerful lever pushing AJAX in other applications. AJAX puts a significantly heavier load on the network by increasing the number of connections, the number of simultaneous connections and the amount of data transferred.
Faster networks, larger objects and AJAX all change the load on the network and the expectations of end users about network responsiveness. Together, these are some of the key forces pushing for WAN acceleration and optimization.
Network managers need to be sure they’re working from the very latest statistics and information on application usage and network characteristics. Data a few months out of date won’t make much difference, but information from a few years ago will be misleading and can result in dangerously undersized devices with the wrong capabilities.
4. Deflate bloated enterprise applications.
Some application developers waste network resources as they write increasingly complex web-based applications. The caching in WAN acceleration and optimization appliances and automated rewriting in application delivery controllers (ADC) can help recover wasted network bandwidth and improve the end-user experience. Network managers should plan for both caching and application rewriting technologies in deploying their WAN optimization solution.
Enterprise applications such as collaboration tools that would seem immune to acceleration are actually prime candidates because of the unoptimized underlying software. Network managers can use WAN optimization tools to speed performance of enterprise applications and collaboration tools by caching application objects, Java and JavaScript, Shockwave Flash and uncompressed images and icons.
Even with caching, network managers should look to ADCs to rewrite application web pages on the fly for an additional performance pop. Third-party tests have shown that ADCs reduce the network load of typical enterprise resource planning applications by up to 80 percent, just by enabling WAN acceleration features.
