Caches can completely eliminate upstream traffic surges caused by heavy demand for a few specific objects. The more people who use Web browsers, the higher the probability that any cache will receive requests for the same objects. Once again, the more users per cache, the more efficient the cache is at reducing upstream traffic. Contents Caching Appliances Caching appliances from companies like NetApps and CacheFlow integrate caching software with a hardware platform and a proprietary operating system. These devices are designed for easy setup and require minimal administration.
Many appliances are rack-mountable like routers and other network devices.
Because appliances have proprietary operating systems, however, it can be more difficult to integrate them with additional hardware or software, or to combine their functions with those of other server-based programs that run on standard operating systems. For example, it would require some additional software engineering work to manipulate an appliance cache's usage data with a Solaris-based database. Server hardware and operating system vendors such as Sun, Novell, and Microsoft offer their own caching products, and third parties like Inktomi offer products as well. Because caching software runs on the same operating system as other network management applications, the data generated by such a cache is easier to integrate with other network management functions. Freshness A cache stores objects, and objects change over time.