How to achieve True Redundancy

Are you experiencing issues with planned and unplanned dark fiber outages that affect your network and organization? This checklist will help you identify and resolve redundancy risks and compromises that might occur in your current setup.

Connections between data centers are the lifelines for your corporate network. Outages on these connections can have a major impact on your business. Cloud applications, voice, data, internet access and data center inter-connectivity services often share the same physical dark fiber route between two or more locations.


Minimizing the risk of losing connectivity and the need for reviewing redundancy risks is often triggered by the following questions:


  • Has our business ever been impacted by an outage of a redundant dark fiber pair?
  • Our carrier sold us two redundant connections, so how come both connections are down at the same time?
  • Are we certain those connections sold as a redundant pair are actually delivered as such?


More often than expected, companies discover that while they might use two different providers as part of their business continuity plans, both vendors rely on some of the same physical infrastructure or dark fiber route.


In the case of a natural disaster or even something as common as a construction accident or burst water main, this will result in losing both their primary connection and their backup at the same time.


DF regio

If redundancy is key, the most obvious place to start is to ensure the network provides redundancy on the optical transmission layer (fiber and wavelengths), by procuring connections with geographically separate paths between data centers.


However, redundant connections aren’t always routed as advertised or contracted and in some cases even overlap due to fiber route reconstruction, introducing a single point of failure.


At AFIBER, we assist in preventing such nasty surprises and recommend using the following checklist for the optimal procurement of redundant data center connectivity.


Checklist for buying diverse data center connectivity:

  • Determine your minimum requirements, do you have a specific route in mind or maximum distance limits? Write down all of your requirements and don’t forget to include a clear network schematic. Then, decide what has priority:
    • Option A: Procure redundant connections from two or more independent vendors to mitigate the risk of vendor failure over the lifetime of the service. The risk of redundancy loss over the lifetime of the service due to fiber route reconstruction remains.
    • Option B: Select one vendor so diversity over the lifetime can be enforced by contract. The risk of vendor failure remains.
  • Find fiber carriers with a strong local focus and who own fiber backbone networks. Request quotes that include digital mapping (‘kmz’) files to check for possible overlaps.
  • Validate that the routes comply with your requirements. Next, shortlist vendors and request formal offers that are explicit on your redundancy requirements.
  • Include the applicable redundancy requirements in your contract with the chosen vendors. For example, have your vendor add network design as an annex. It’s critical to include termination clauses, especially geared toward the inability of your chosen vendor/s to meet your redundancy requirements. Don’t rely on the 5-nine availability in the SLA as the penalties vendors receive for failing to meet SLA thresholds are usually minimal compared to the impact an outage will have on your business.
  • Include data center cross connects in your network risk analysis, OTDR measurement validation and operating procedures. Most companies have no direct control over their network and rely on third parties to keep the facility operating and connectivity up, so include them in your test and recovery plan.
  • Verify configuration of optical and active network equipment to accommodate two or more physical fiber connections.
  • Set up regular auditing frameworks to verify compliance with set requirements and vendor stability. This last step is often overlooked but crucial if your network has to switch do a redundant path.


At AFIBER, we’re committed to mission critical connectivity. We offer our expertise to assist with diverse connectivity on our own fiber network and to select the right alternative networks from which to source maximum network continuity. We deliver diverse redundant on-net dark fiber and dark wavelength connectivity within five working days, including a guaranteed kmz-file.


Stay clear from outages, configure and request your redundant service here. We also offer short-term dark fiber services starting from one month, available on request. Get in touch with our team for a quick scan at or +31(0)20 225 0025.


AFIBER empowers clients with software controlled, network-independent optical transmission services. We operate fiber networks with elastic optical transmission capabilities. Our clients range from national SMB’s to global enterprises with over $100bn in yearly revenues.


AFIBER services are built on the company’s core strength: leveraging technology and connectivity efficiencies to allow customers integrate, distribute and manage high performance data transport across organizations, data centers and customers more effectively.


For more information learn more or get in touch.