WAN Application Deliver Solutions
WAN application delivery solutions
WAN application delivery has emerged as one of the most important technologies in solving performance and accessibility problems for applications delivered over the Internet. WAN application delivery solutions were built to address WAN infrastructure complexity, performance, scalability and security issues.
These solutions may be known as application delivery controllers (ADC), global load balancers (GLB), WAN link controllers, dual WAN routers, multihoming switches and WOCs. In order to avoid confusion, this article refers to specialized WAN optimization controllers that have link load balancing and failover capabilities as WAN link controllers. WAN link controllers actually evolved from global load balancers that were first introduced in the late 1990s.
WAN link controllers direct Internet traffic to the best performing, most accessible WAN links. Should one link become inaccessible due to a bottleneck or failure, the WAN link controller will take that link out of service and automatically direct traffic to other functioning links-a virtually seamless process.
Bundling multiple, diverse Internet links from one or more ISPs, WAN link controllers reduce the need to purchase multiple, expensive high-speed links. This enables businesses to increase bandwidth by using cost-effective links without compromising uptime. In addition to managing scalability and redundancy, WAN link controllers can be used to cost-effectively utilize all available WAN bandwidth through site-to-site channel bonding. WAN link controllers can provide QOS controls for determining how bandwidth is used to support specific applications.