wan optimisation

WAN Optimisation fits the bill for disaster recovery

http://www.wanoptimization.org

Disaster recovery requirements are now far more pressing and diverse than they have ever been, due to a combination of compliance-related regulations, data centre expansion, the proliferation of remote offices and employees, and server virtualisation. That means you need to be able to exchange data between primary and recovery sites as quickly as possible with as much bandwidth as you can afford between the two endpoints. In many cases, you will need to make the most of the bandwidth you have, and one way to do that is to deploy WANoptimisation technology.   
This additional complexity in terms of how and where disaster recovery is deployed creates potential bottlenecks, especially when running across public networks. Latency in particular becomes a major problem on relatively low-bandwidth connections with multiple hops between the source and destination points. WAN optimisation deals with these issues.
By minimising latency, making greater use of the available bandwidth and potentially reducing the amount of bandwidth required in the first place, WAN optimisation can help reduce disaster recovery costs, which can make disaster recovery feasible over a link where it previously wasn’t possible.
WAN optimisation methods
WAN optimisation products typically are not based around a single acceleration or optimisation methodology but rather a combination of techniques, including the following:

• Bandwidth management and traffic shaping. This involves assigning a priority to a particular type of application, which has an effect on the order the traffic is sent in and in the amount of bandwidth the application is guaranteed regardless of other traffic on the network.
• Protocol optimisation. This takes protocols that are inefficient over the WAN and makes them more efficient, typically by converting a time-consuming serial communication process into a more efficient parallel process with many communication tasks handled simultaneously.
  • Byte caching. This observes repetitive patterns in all TCP-based application traffic and symbolises those patterns with a token that replaces that traffic, thereby minimising data transfer.
  • Object caching. This is protocol- and application-specific. If the cache contains the object, the user is immediately served the object from a local store, virtually eliminating latency and WAN bandwidth consumption. If the cache does not contain the object (or contains an outdated version of the object), for that particular transaction, a new object must be reloaded into cache and the performance gains are realised in full the next time the object is requested. Some forms of object caching compare new with old and only send the changed data and reconstruct the object locally.

 What’s next in WAN optimisation?

http://www.wanoptimization.org

One innovation just around the corner is the ability to predict data transfer requirements and begin the transfer process before it has even been requested, based on analysing user and file behaviour remotely. So, in a scenario where data has to be retrieved urgently, the request will already be primed, resulting in a much faster retrieval time. There is also an argument being put forward to replace Multiprotocol Label Switching (MPLS) networks completely with simply architected networks using WAN optimisation. MPLS is a notoriously expensive methodology for deploying and managing networks, so the rationale, from a disaster recovery perspective, of simplifying the network architecture and, at the same time, optimising what bandwidth is available makes a lot of sense.