WAN optimization is a collection of techniques for increasing data-transfer efficiencies across wide area networks.
WAN can be optimized by these techniques:
Web Caching: Web Caching can be achieved by the use of proxy server.The proxy-server keeps the frequently requested pages in the cache , requested from the external web server.So,next time when the request again comes from the client, proxy server returns back the stored cached page and thus saves a lot of time.
Pages Stored in Proxy Server's Cache
DNS Caching:Domain name server provides a service which helps in resolution of the domain names to their respective IP addresses.For eg. Domain google.com belongs to the IP address 188.8.131.52.Domain name servers also maintain a cache which contains the mapping of frequently used domain names to their IP address.DNS caching, thus saves a lot of time as each and every time we do not go for domain name resolution and we can find a appropriate entry in cache.
Content Filtering Proxy servers help us achieve the content filtering , as whatever is sent back by the external network must by-pass the proxy server.Unwanted content does get blocked by the proxy server.
Deduplication is defined as eliminating the redundant data so as to reduce storage needs across the network.It stores only the unique data and rest of the redundant data bits can be replaced by reference points.
Forward Error Correction is technique in which data transmitted can be corrected at receiver’s end ,so thus need of re-transmission is eliminated.The data that implements FEC contains an Error correcting code along with the actual data.
Quality of Service:Quality of Service refers to such mechanisms which allow the flow of traffic with certain requirements.QOS offers us two kinds of services