Monday, April 20, 2009

Proxy Caching_Wan Optimization

WAN optimization is one of the techniques to improve the speed of functional tools so as to maximize the business performance and to proactively solve the problems.

WAN optimization products seek to accelerate a broad range of applications accessed by distributed enterprise users via eliminating redundant transmissions, staging data in local caches, compressing and prioritizing data, and streamlining chatty protocols (e.g., CIFS).

Improving the application response time is the main benefit that is accrued out of WAN optimization and this is essential where there is centralization of servers and IT resources. When you optimize WAN, you are also saved from the cost of upgrading the band widths.

WAN Optimization is a superset of WAFS in that it also addresses:

Component techniques of WAN Optimization include WAFS, CIFS proxy, HTTPS Proxy, media multicasting, Web caching and bandwidth management.

A few WAN/Internet Optimization techniques:

Compression - Relies on data patterns that can be represented more efficiently. Best suited for point to point leased lines.

Protocol spoofing - Bundles multiple requests from chatty applications into one. Best suited for Point to Point WAN links.

Traffic shaping - Controls data usage based on spotting specific patterns in the data and allowing or disallowing specific traffic. Best suited for both point to point leased lines and Internet connections.

Equalizing - Makes assumptions on what needs immediate priority based on the data usage. Excellent choice for wide open unregulated Internet connections and clogged VPN tunnels.

Connection Limits - Prevents access gridlock in routers and access points due to denial of service or peer to peer. Best suited for wide open Internet access links , can also be used on WAN links.

Simple Rate Limits - Prevents one user from getting more than a fixed amount of data. Best suited as a stop gap first effort for a remedying a congested Internet connection or WAN link.

Proxy caching accelerates service requests by retrieving content saved from a previous request made by the same client or even other clients. Caching proxies keep local copies of frequently requested resources, allowing large organizations to significantly reduce their upstream bandwidth usage and cost, while significantly increasing performance. Most ISPs and large businesses have a caching proxy. These machines are built to deliver superb file system performance (often with RAID and journaling) and also contain hot-rodded versions of TCP.

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