WAN to the max
Optimization tools can help boost network efficiency, reduce strain on bandwidth
- By Maggie Biggs
- May 01, 2008
Smart sprinters working to improve their times don't just work on increasing muscle mass. They also work on improving their technique. In similar fashion, adding powerful ' and expensive ' new equipment isn't the only way to boost performance on your agency's wide-area network. Technique counts for a lot, and one technique that can deliver major gains is WAN optimization.
Organizations that have implemented WAN optimization have discovered vastly improved application performance. And there are several other benefits downstream, including the ability to consolidate data centers and servers, centralize and accelerate backup strategies, improve disaster recovery capabilities, and reduce bandwidth costs.
That last point is one of the primary drivers toward WAN optimization. 'WAN optimization can decrease link utilization from 80 percent to 40 percent by using [a combination of] caching and compression,' said Robert Whiteley, principal analyst and research director at Forrester Research.
Through a combination of reduced bandwidth costs, increased data center and server efficiency, improved backup strategy, and productivity gains brought about by application acceleration, organizations can quickly realize a positive return on investment.
'We've seen clients with highly latent international [WAN] links see a return on investment in as short as three months,' Whiteley said. 'If you have a regional or national network, you can expect a 12- to 18-month ROI.'
Some agencies look to achieve all of the WAN optimization benefits. 'We have several remote branches, many connecting through satellite links,' said Tom Bimson, strategic planning manager at Service Canada, which gives residents a single point of access for government services. 'Network performance has been a concern for some years, and it is getting to be more of a problem as users demand a richer experience.'
Bimson said his agency also is interested in continuity planning, enabling large file transfers between primary and backup data centers and reducing dependence on distributed servers. 'Enhancing WAN performance can make this happen,' he said.Four techniques
At its core, WAN optimization ' sometimes also called WAN acceleration ' aims to improve application performance by increasing throughput and decreasing latency across network links. Typically, hardware or software at both ends of a WAN link work in concert to achieve optimal performance.
WAN optimization commonly encompasses four techniques ' caching, protocol optimization, compression and traffic management.
Caching data locally at remote locations requires fewer trips across the WAN.
Protocol optimization reduces latency by addressing inefficiencies in protocols, such as Microsoft's Common Internet File System. CIFS typically is used in Windows-based file-sharing environments.
Network traffic compression helps increase throughput across WAN links. Meanwhile, traffic management techniques use quality-of-service provisions to shape bandwidth and prioritize traffic on the network.
There is no single approach to WAN optimization. The Navy, for example, could improve ship-to-shore connectivity on a variety of link types by using a combination of optimization hardware and software to increase performance.
Dan O'Barr, systems administrator at the Nevada Department of Corrections, said he has noted a significant improvement in response time since implementing WAN optimization. 'It's important that the application has a fast enough response time to make its use interactive, even to our most remote locations,' O'Barr said.
WAN optimization also can help agencies push green initiatives. By blending WAN optimization with fewer, consolidated data centers using virtualization, an agency can improve performance while using less power.
Beyond the data center, workforce distribution is playing a key role in driving WAN optimization. 'Today, our data shows that more than 70 percent of the workforce works outside of headquarters,' Whiteley said.
WAN optimization footprints can address a variety of computing situations. For example, WAN optimization devices might be implemented between two agency data centers to improve performance in redundant data center settings.
Likewise, devices can be implemented between data centers and branch offices or business partners to speed performance and reduce the number of servers required.
A combination of hardware in the data center with software on the client side ' which administrators often can remotely install across a virtual private network ' can be used to implement WAN optimization for mobile and remote workers. Furthermore, some software-only solutions can be implemented between an agency's central location and remote participants.Branching out
Although WAN optimization has been around for a while, there are several new trends in the field.
Wide Area File System implementations formerly were devoted to addressing inefficiencies with CIFS and other so-called chatty network protocols.
Today, WAFS is considered a subset of the broader WAN optimization picture known as WAN Data Services. Most vendors support WAFS and WDS in their WAN optimization implementations.
WDS goes further than WAFS by optimizing additional protocols, such as Secure Sockets Layer, HTTP, Extensible Markup Language and even pure TCP/IP. In addition, caching, compression, prioritization and optimization are being applied to other types of data streams, such as video and audio.
Optimization of SSL and multimedia traffic are two of the fastest growth trends in WAN optimization. However, solution providers in the WAN optimization marketplace support varying protocols and methods to streamline network traffic. Agencies should carefully compare their network usage with vendor capabilities.
Traditionally, WAN optimization has been achieved via pairs of hardware devices placed at complementary sites, such as data centers and branch offices. With the changes in workforce distribution, agencies are implementing more hardware/software and software- only WAN optimization solutions.
Major carriers such as AT&T are examining the possibility of offering WAN optimization as part of managed-service offerings. Agencies should consider not only existing network traffic trends but also changing topologies and workforce demographics when selecting a WAN optimization solution.Product options
More than 20 providers of products and services address WAN optimization in some way at prices ranging from $3,000 to more than $25,000, depending on the scope of features.
The devices include Riverbed Technology's Steelhead appliances and Interceptor device and Blue Coat Systems' SG appliances. Cisco Systems' approach includes its WAE appliances and WAAS software. Other providers of optimization tools include Citrix Systems, Expand Networks, F5 Networks, Juniper Networks, Packeteer and Silver Peak.
Relative newcomer Replify reflects a likely future direction of WAN optimization: software- only solutions. The company's Reptor solution takes advantage of VMware products that are possibly already running on agency servers to implement server-side WAN optimization. In addition, Replify provides companion client-side software that agencies can implement via private WAN links or VPNs to enable WAN optimization for branch offices, business partners, and remote and mobile workers.Successful implementation
WAN optimization can be fairly straightforward. Bimson executed a proof of concept for WAN optimization and said, 'We implemented gear in remote sites to speed e-mail, calendar, and file and print services. User reaction was very positive, and our network administrators found the implementation and ongoing maintenance reasonably painless.'
By capturing network statistics and user experience before and after implementation, agencies can determine the relative success of their WAN optimization initiatives. 'We saw dramatic decreases in WAN bandwidth consumption [and] speedier access to files and e-mails, and we received sincere thanks from our proof-of-concept users,' Bimson said. 'Our defined success criteria were exceeded.'