Network-Integrated Caches

Network-Integrated Caches

The first step in creating a network-integrated cache engine is to ensure that the network supports traffic localization, which can be achieved by enabling content routing technology at the system-level, and setting specific parameters to optimize network traffic. Cisco IOS ® Web Cache Communication Protocol (WCCP) is one example of content routing technology that can be set to support traffic localization.

Once the right network foundation is in place, network caches are added into strategic points within the existing network.

By pairing software and hardware, Cisco creates a network-integrated cache engine.

Network-integrated caches have at least the following three properties:

• Managed like networking equipment, resulting in minimized operational costs

• Designed like high-density networking hardware, resulting in better physical integration into the network infrastructure as network extensions and minimizing costs associated with leasing rack space

• Transparently inserted into the network, resulting in minimized deployment and operational costs and greater content availability

Existing Caching Solutions

The three most common types of caches on the market today are proxy servers, standalone caches, and browser-based caches.

Proxy Servers

Proxy servers are software applications that run on general-purpose hardware and operating systems. A

proxy server is placed on hardware that is physically between a client application, such as a Web browser, and a Web server. The proxy acts as a gatekeeper that receives all packets destined for the Web server and examines each packet to determine if it can fulfill the requests itself; if not, it makes its own request to the Web server. Proxy servers can also be used to filter requests, for example, to prevent its employees from accessing a specific set of Web sites.

Unfortunately, proxy servers are not optimized for caching, and do not scale under heavy network loads.

In addition, because the proxy is in the path of all user traffic, two problems arise: all traffic is slowed

to allow the proxy to examine each packet, and failure of the proxy software or hardware causes all users

to lose network access. Expensive hardware is required to compensate for the low software performance

and the lack of scalability of proxy servers.

Proxies also require configuration of each user's browser—a costly and unscalable management task for

service providers and large enterprises. In addition, proxy servers that are arranged in a hierarchical

fashion form an additional overlay network, contradicting any plans to strategically converge disparate

networks into a single, unified network.

Standalone Caches

In response to the shortcomings of proxy servers, some vendors have created standalone caches. These

caching-focused software applications and appliances are designed to improve performance by enhancing the caching software and eliminating other slow aspects of proxy server implementations. While this is a step in the right direction, these standalone caches are not network integrated, resulting in higher costs of ownership and making them less desirable for wide-scale deployment.