Devising an application networking strategy starts with sorting through the options and determining which ones are most important to your organization.
Application networking spans at least two big product categories. They are:
- Asymmetric application acceleration at the server level: This speeds performance through load balancing, caching and offloading tasks such as Secure Sockets Layer (SSL) encryption. F5 first gained fame helping large Web sites balance the workload for huge numbers of users and transactions across multiple servers. Citrix, with its NetScaler product line, is another major player in this market.
- WAN performance optimization: This typically requires a matched pair of devices from the same vendor at each end of the WAN connection. Vendors include Riverbed, F5 Networks and many others.
And then there's Cisco, which in January announced improvements to its application networking services portfolio, including a model in its application control engine appliance line, a mobile client for its wide-area application services (WAAS), its WAN acceleration system, and a testing and validation partnership with application vendors. While Cisco claims the greatest breadth by also providing so much of the basic routing and switching infrastructure for corporate networks, it's not as dominant in application networking.
"Cisco enjoys significant market share, but almost all of it is the old load-balancer market," Gartner's Skorupa says. Enterprises that aggressively employ the most sophisticated application networking techniques typically supplement whatever they get from Cisco with specialized products from other vendors, he adds.
Still, many Cisco customers put a premium on the network management advantages that come from using the vendor's products when possible. "It's always been our goal to limit the number of vendors we have," says Richard Bell, the manager of network engineering at auto brokerage service AutoByTel.
The firm uses Cisco's content services switch products as application accelerators for both its public Web site and its business-to-business network connections. The latter category includes XML messages the company exchanges with other brokerages to determine who can fill a particular order, and it's critical to eliminate any unnecessary delays in those transactions. "There has to be a response in two or three seconds, or they'll sell the lead to someone else," Bell explains.
Southco, which makes hinges, latches and other hardware, is another primarily Cisco shop, but it went with Riverbed for its WAN acceleration needs, says network security specialist Jesse Middleton. The evaluation team he led chose Riverbed because it had the best tools for measuring the impact on network performance.
"From a business perspective, it's always good if I can print out a report that says I increased bandwidth by X amount as of right now," Middleton says. Specifically, he could claim the technology had boosted the effective bandwidth of WAN links by about 3.5 times, while avoiding the need for costly network upgrades.
If you must choose where to put your money, or what to implement first, consider which applications in your organization are most in need of a performance boost. Do they fit into a WAN acceleration scenario, in which latency across long distances is a challenge and you control both ends of the network link? Or are they consumer-facing Web applications or business-to-business connections with partners whose networks you don't control?
One advantage of the application controller products that evolved out of load balancing and Web caching technologies is that they speed up application performance for everyone: public users of a Web site, mobile workers, employees within the firewall and business partners that connect over the Internet. Caching techniques that reduce the load on Web and application servers improve application responsiveness for everyone.
So does offloading the processing required for SSL encryption from the server onto a specialty network appliance built for that purpose. These techniques generally don't require anything special on the client side, other than some standard compression/decompression mechanisms built into modern Web browsers.
Though the performance benefits of application controllers extend to clients on the other end of a WAN link, they don't address all the same challenges as the WAN-specific acceleration appliances.
In addition to the branch-office scenario in which a WAN appliance makes sense, vendors such as Riverbed have extended their technology to cover mobile workers with a software-only client that can be installed on a laptop and link directly to a corporate network. The laptop acts as its own network acceleration appliance. Cisco's WAAS Mobile is its entry in that market.
Gartner's Skorupa believes that most enterprises have not developed the full potential of application networking in a strategic way. WAN acceleration appliances often can improve network utilization by 90 percent to 95 percent, he says, letting enterprises postpone bandwidth upgrades at a significant saving, while continuing their consolidation efforts. In addition, application controllers often serve a larger population of users with fewer servers.
"It's not uncommon to improve the efficiency of your application architecture by 20 percent to 50 percent, and when you reduce the number of servers, you also reduce the number of licenses you have to buy," Skorupa says. The latest generation of these products includes features that most companies haven't begun to tap, such as the ability to protect against security vulnerabilities at the network level, rather than by recoding software.
"That can mean the difference between getting a change made in three days versus three months," he says. "If you're talking about rewriting the application, it's hard to get anything done in less than a month."
Ask your IT staff: Does our default networking equipment vendor have the best products to address our needs? Do the advantages of sticking with a single-vendor solution outweigh the virtues of more specialized vendors?
Ask the vendors: Does your architecture encompass WAN acceleration and asymmetric application acceleration? If so, what advantage will I get from buying both from you?