Network Diversity Strategies in a Business Continuity Plan - Part 1

Telecommunication carriers have specific solutions that can be part of any business continuity plan. Future articles will address these types of solutions. This article will focus on some fundamentals of mitigating connectivity risk using diversity. The main principal of diversity is to have a variety of different elements in a system that can accomplish the same task.

Today more than ever, companies need to insure that their operations are not disrupted. Extended disruptions jeopardize the health of the business and customer loyalty. It seems clear, the longer a business experiences interruptions the more likely it will lose customers and not recover. A business continuity plan uncovers vulnerabilities and address's ways to minimize the impacts of those vulnerabilities. A qualified business continuity professional can assist with such a plan. In addition to a Business Impact Analysis, other IT assessments could include: Remote Vulnerability, Data and Storage Protection.  

Today, carrier networks are designed to be resilient. At the core of a carrier's network are redundant and diverse connectivity paths, building entrances, meshed network topology, and back-up CPE along with mirrored data centers. Business customers can employ some of these same strategies.

Carrier diversity would include an alternate carrier circuit. Load balancing with CPE on the business premises or with BGP allows the network to share two different carrier connections. If one carrier goes down the second would provide  uninterrupted connectivity. Carrier diversity mitigates the risk of a carrier experiencing an interruption, typically at a core router. But what if both carriers have their cable along the same path and they are both cut? Access diversity addresses this risk.

Access diversity includes a different type or location of access. This might mean having alternate circuits enter from the other side of the building. This is only diverse to the point where the two circuits merge into the same conduit. Alternate access could also include a different type of access such as cable or wireless. Cable providers especially have a completely separate network from the embedded telco infrastructure, bypassing even the telco’s central office. This mitigates the risk of a “the last mile” cut. Again, employing a load balancing strategy helps ensure on-going connectivity in the event of a line-cut.

Carrier back-bones are typically built on MPLS platforms which provides resilience to the network. Unlike a hub and spoke architecture, MPLS is considered a “meshed network topology”. Any and all locations are connected to each and all. So, if one location “goes down” the other locations are still connected and unaffected. MPLS services are not just available to carriers. Many multi-location enterprises utilize this architecture today.

If the Business Impact Analysis determines that the business can not afford to be disrupted for even a small amount of time then it would be wise to consider collocating critical systems and applications into a data center. Data centers mitigate the physical risks associated with having the core technology functions reside on the business premises. Risks mitigated are fire, flood, wind damage, power outage, fiber cuts and telephone pole destruction. Data centers have battery back-up, diesel generators, environmental controls, and multiple power and carrier connections. In short, your physical business location could be on fire and all of your critical information and systems are still up and running in the data center. Data center collocation is almost a requirement if your network needs to always be available.

A common strategy might be to maintain a duplicate inventory of equipment. Having duplicate CPE implies that the business has the technical resources to make a speedy replacement at any hour. In almost all cases this strategy is not cost effective or efficient. As we have discussed above, much more than just hardware needs to be considered in business continuity planning.

Probably, the most expensive and risky strategy is to do nothing. Incorporating some diversity strategies in a telecommunication infrastructure can go a long way in avoiding an extended business interruption.


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