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U.S. Retailer Uses F5 Solution to Manage Huge Traffic Load and Avoid Spending Millions

A large U.S.-based retail store chain had less than a month’s notice to provide  computing support for up to 2,000 new customer service agents, brought in to handle a higher than normal call volume during the holiday season. To provide the capacity needed, the company considered deploying up to 150 new servers or reconfiguring existing servers, but both options would be time consuming and costly. Instead, the company chose an F5 solution, which solved the problem within days using only four new devices. By eliminating the need for new servers and reconfiguration, the F5 solution saved the company substantial capital and operational costs, increased its processing capacity, and enabled it to manage traffic effectively.

Business Challenges

The IT department at one of America’s largest retailers manages several thousand web-based enterprise applications, such as those from Microsoft, SAP, and Oracle, as well as custom applications. These applications run on thousands of servers across multiple data centers. Applications are made available to users via Citrix XenApp, a solution that delivers applications as a service to users on any device.

A typical consumer of these applications was the retailer’s customer service organization, which employed about 100 agents to handle customer service calls.

During non-peak season when call volume was moderate, all customer calls were routed to a single server. “From a network perspective, the call centers and data centers were connected in such a way that all agent requests appeared to originate from the same IP address,” said the company’s IT manager. “Because the Citrix environment couldn’t distinguish one user from another, those requests were all sent to the same server. If that server became overloaded, it would fail over to another server; if that one became overloaded, it would fail over to another server, and so on.”

Due to a change in its business and operational strategy, the company needed to quickly ramp up an additional 2,000 agents to take on the anticipated increase in call volume during the 2011 holiday season.  “We knew that one server would not be able to handle the volume of server requests coming from more than 2,000 agents.”

Without the flexibility to distribute traffic across multiple servers, the IT team needed a way to quickly provide more processing capacity. One option was to expand its server farm, deploying up to 150 new servers to handle the additional traffic load. Another possibility was to temporarily reconfigure a large number of existing servers, and then restore them to their previous configurations when traffic volume returned to normal.  Both options would require assigning (hard coding) users in groups of 40 or 50 to dedicated servers, and all 2,000 workstations would need to be configured individually.

Given that time was a non-negotiable parameter, neither of these expansion plans was particularly feasible, and both options would be extremely costly. The IT team needed a straightforward, workable solution that could be deployed in a matter of weeks with the least amount of disruption to operations.

“We chose F5 based on our confidence in them and their ability to deploy a solution quicker than any other vendor at a dramatically lower cost.” IT Manager, Large U.S. Retailer


With a decade-long history of relying on F5 to optimize the delivery of its enterprise applications, the retailer turned to F5 for help. It already used F5 BIG-IP Local Traffic Manager (LTM) and BIG-IP Global Traffic Manager (GTM) to enhance security, improve performance, and intelligently direct traffic for thousands of applications across its two data centers. “We chose F5 based on our confidence in them and their ability to deploy a solution quicker than any other vendor at a dramatically lower cost,” said the IT manager.

The IT team solved the support center traffic management problem by deploying BIG-IP Access Policy Manager (APM), the F5 user access and authentication product, on a pair of BIG-IP devices in front of the XenApp servers in each data center. By passing all server requests through the BIG-IP devices, the IT team can use BIG-IP APM to identify the individual IP addresses of support center agents, distinguishing one user session from another. Server requests are then sent into the Citrix environment, where they can be load balanced across multiple XenApp servers rather than being sent to a single, dedicated server.

“F5 was the only vendor that could provide a reliable, fully functioning solution within such a tight time frame.” IT Manager, Large U.S. Retailer


Using an F5 solution, this mega retail chain was able to react quickly to solve its immediate need for additional processing capacity, and it improved its ability to manage traffic. Requiring only a fraction of the equipment needed to implement the alternate solutions, the F5 solution enabled the company to avoid spending millions on an alternate solution and enabled it to better utilize its existing computing resources.

Rapid deployment, easier administration

Cost is typically a primary concern for customers, but for this company, it was secondary to its requirement to deliver the project on schedule—within just three weeks. The IT team leveraged F5 iApps, a powerful set of tools in the BIG-IP system, for deploying application services 10 to 100 times faster than normal and with up to 95 percent fewer errors. IApps includes many configuration templates, including one specifically designed for Citrix XenApp and XenDesktop deployments with BIG-IP APM.  Using iApps, the team was able to install the BIG-IP devices within hours, and had them fully configured and operational within days.

“F5 iApps is an incredible time- and error- saving tool. It would have been impossible for us to deploy 150 new servers—or even reconfigure existing servers—and have them operational that quickly,” said the IT manager. “F5 was the only vendor that could provide a reliable, fully functioning solution within such a tight time frame.”

Improved capacity, performance, And availability

A significant benefit the F5 solution provided was the ability to intelligently manage user connections coming into the Citrix servers. With this new and powerful flexibility to distribute traffic across multiple servers, the company can easily handle huge surges in traffic load whenever they happen.  In addition, because the BIG-IP devices offload SSL processing, the Citrix servers are better utilized, providing additional capacity for growth.

Substantial CapEx and OpEx savings

For this retailer, the financial savings of the F5 solution amounted to cost avoidance.  Conservatively, 150 new servers with appropriate licensing would have cost the retailer between $750 thousand and $1.5 million. The F5 solution also eliminated the substantial operational expense of installing, configuring, testing, monitoring, and backing up those servers. Equally important, F5 enabled the company to avoid the enormous cost of expanding its data centers to house, power, and cool additional servers.