CBS, the first private broadcasting station in Korea and a company that has consistently aimed at providing reliable and fair broadcasting over its 53-year history, established its Web portal, CBS Internet News (CBSi) in 2000. CBSi operates CBS Christian Broadcasting Radio and TV site (www.cbs.co.kr) and Nocutnews(www.nocutnews.co.kr), which provides live news, uncut, that no other media can access. The company strives to provide accurate and rich information to viewers and listeners in a timely manner.

The Challenge: Ensuring Stable Web Site Operation During Traffic Spikes

Thanks to broadcasts of exclusive reports, as well as reports on hot social issues, the number of visitors to CBSi is constantly increasing. The company was especially worried about traffic congestion on the Nocutnews site operated by CBSi. When a sudden increase in traffic was anticipated, due to an exclusive report or some specific issue, an administrator had to stand by, 24 hours a day.

As Jeoung Soon Han, manager of the CBSi Solution Team, explained, “There were some cases where we were not able to provide the service effectively, due to sudden increases in traffic when we were broadcasting exclusive or special reports. Furthermore, it was apparent that the traffic would increase further if users access Nocutnews directly from portal sites. As well, since CBS is a Christian Broadcasting Company, users are constantly accessing the site, 24 hours a day, from all over the world. Thus, the key was to ensure the stability and availability of the Web service.”

Implementing Citrix NetScaler

Various methods of improving Web site performance were reviewed, such as using a Web accelerator. With the recent drop in server prices, an increase in the number of servers was considered. However, in view of the increase in server management and manpower that would be needed, it was decided that a simple expansion of servers was not a realistic approach for handling irregular traffic volume.

CBSi made a decision to adopt Citrix® NetScaler®, as it can stably accommodate increased amounts of traffic without requiring a separate extension of servers. NetScaler optimizes Web application transmission, and increases security. The solution is currently being applied on the CBS and Nocutnews sites, as well as 13 regional sites.

CBSi first optimized TCP through TCP offload and reusing TCP sessions. Next, by applying load-balancing functions, the team increased speed by processing requests rapidly with fewer connections. The use of caching memory was reduced through HTTP compression and the application of dynamic caching.

Jeoung Soon Han said, “NetScaler has the effect of reducing traffic by reducing server load and through the use of caching. It displays excellent performance in reducing server resources through TCP reduction and HTTP compression technology.”

Increasing Web Site Speed and Stability

By introducing Citrix NetScaler, CBSi was able to increase the stability and reliability of its Web service without an investment in additional servers. This reduced costs and maximized performance and availability.

The biggest effect is ensuring uninterrupted service by distributing momentary increases in load. This has actually resulted in a 35-fold improvement in client connections through TCP optimization. Load is processed equally through the L7-based switching function. NetScaler also defends against DDos (denial of service) attacks, which crash sites by causing a sudden traffic increase, and thus has increased the availability and stability of CBSi’s Web sites.

With Citrix NetScaler image caching and dynamic caching, there is no need to repeatedly create application data requested by users. This caching function can reduce the entire Web application server response load by 76 percent, thus improving the performance of the Web server and the database server.

Also, one of the biggest advantages of NetScaler has been a large reduction in management costs, in contrast to other solutions, such as the expansion of servers. The Citrix solution increases management efficiency while providing a convenient graphical interface and real-time monitoring.

“We were able to ensure stability and guarantee extensibility by introducing Citrix NetScaler,” said Jeoung Soon Han. “In terms of efficiency, it was two or three times more effective economically than expanding our servers. It reduced fixed expenses related to management, such as manpower, by more than 50 percent.

Future Plans

In the coming year, CBSi plans to introduce the latest version of NetScaler to further enhance security. The company considered purchasing Web firewalls separately, but the new release of NetScaler with its integrated application firewall capability seemed a better solution, since it will reduce management. In the long run, it is expected that stability will be enhanced further if dualization is applied by purchasing additional NetScaler appliances.

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