Disaster recovery, in theory, is simple: take all your data and copy it to somewhere off-site to keep it safe but still readily accessible in the event of an emergency. But with the size of critical data growing exponentially, disaster recovery (DR) can quickly become a cumbersome and costly exercise – one that can determine if a business makes it through an emergency.Typically organisations buy a DR solution as a managed service or build their own primary and secondary data centers. Either solution involves sending data over considerable distances and the further away you are from the data, or the data centers are from each other, the greater the delay in transmission. Sending large amounts of data over a wide-area network (WAN) can be very expensive as bandwidth is costly, and if an organisation has enough data – and the links are too slow – it may not even complete the back up in the designated time each day, risking the loss of critical data. Ideally, DR protection needs to be fast, secure and inexpensive. But as a reseller, what can you offer your customers to make this a reality? You could recommend extra bandwidth which might address the load issues, but will add to the cost of the solution. To truly offer the best and most cost-effective solution, one that works with existing infrastructure and enhances the day-to-day operation of a business at the same time, resellers need to know how organisations deploy and measure DR protection.Disaster Recovery 101Disaster recovery protection is typically handled by either regular backups, or by constantly replicating the data on the system. Assessing the effectiveness of DR protection takes into account two measures: recovery point objective (RPO) and recovery time objective (RTO).RPO is the amount of time between data backups or, put another way, the amount of data an organisation believes it can afford to lose. A company which backs up its data daily, for example, has set its RPO at one day, meaning it can afford to lose a day’s worth of work in the event of a disaster. Organisations which rely on critical data, such as banks and hospitals, are constantly replicating the data on their systems because the amount of data they can afford to lose is much less than most businesses, and in some cases they can’t afford to lose any data at all. RTO is the amount of time a business can afford before its systems come back online following a disaster. No work can be done during this period of ‘downtime’. In an April 2010 Enterprise Strategy Group research survey organisations were asked about the amount of downtime they could afford in the event of an emergency before experiencing significant revenue loss and other adverse impacts to the organisation. Eighteen per cent of respondents claimed they couldn’t afford any downtime, while a further 74% of the companies surveyed said they could only tolerate three hours or less.Meeting these objectives is critical to the life or death of a business during a disaster. A failure to do so can lead to fines or penalties for being out of legal compliance in some government-regulated enterprises, and can lead to potentially catastrophic failures across all businesses.WAN OptimisationA proven way for organisations to meet their RPO/RTOs is to reduce latency and bandwidth requirements by reducing the amount of data sent across the WAN. This can be achieved by deploying WAN optimisation technology. WAN optimisation incorporates three techniques that can significantly increase speed and bandwidth across the WAN securely and inexpensively:Deduplication When a chunk of data is sent across the WAN, regardless of the protocol or who sent it, it is not sent a second time. For example, when sending a multi-megabyte or gigabyte-sized chunk of data, deduplication technology sends a 16-byte pointer to information that is already on the WAN, rather than sending the whole file again. Because such a large percentage of disaster recovery data is replicated, efficiency across the WAN can be increased by anything between 65% and 95%.Application/Layer 7 OptimisationIn conjunction with DR vendors, application optimisation reduces the traffic travelling back and forth across the WAN, which can increase efficiency by a further 60% to 90%.Optimising the TCP protocol With WAN optimisation appliances at each end of the network, the TCP protocols themselves can be optimised by tweaking certain parameters between the appliances. The goal in DR is to flood the pipe with as much data as possible going one way, and for this to happen there are two versions of TCP: high-speed TCP and Max TCP. Max TCP is designed for a dedicated network and will flood the connection with data, while high-speed TCP is designed for a shared network which takes better advantage of the available bandwidth than regular TCP protocols while still allowing other users to share the same network.Deploying these techniques for disaster recovery protection effectively eliminates backup in branch offices. When the WAN is properly leveraged to replicate and backup the data in branches, a company can save on the costs of localised backup related to hardware, software and administration. Not only does this remove the cost and vulnerability of tape backups, the RTO is greatly improved as data can be restored across the WAN instantly. Optimising the WAN allows the business to transport not just mission-critical data, but all data. With replication and backup now up to 45 times faster across the WAN, a business can easily make its backups, including backup of mobile devices, within its designated timeframe. For the business that can only backup daily, optimising the WAN means it can afford to back up its data on a far more regular basis.Added bonusOptimising the WAN isn’t only ideal for DR protection, as deploying these techniques also improves application performance across the WAN. While tape replication and offsite transport can be time-consuming and costly, WAN optimisation works in the background and complements the whole business, delivering a more substantial return on investment.Not only does WAN optimisation ensure disaster recovery is more reliable, it ensures the day-to-day performance of the WAN is efficient, inexpensive and secure. As a reseller, WAN optimisation gives you a proven, holistic solution to consult back to your customers which goes beyond what’s possible with a stand-alone DR product.