The Basics of Network Redundancy

On average, unplanned network outages cost nearly $9,000 per minute!


Network redundancy is an integral part of an enterprise business communications plan. A redundancy or disaster recovery plan identifies the critical components of the network where a failure would cause significant outages. In the event of a failure with these various communications links or devices, redundancy allows your network to remain in service by providing alternative communications paths and backup equipment.

So what costs are at stake for your business?

Direct Cost - The direct expense outlay to accomplish a given activity. Direct costs would include the cost to detect and control the incident, possible equipment damage, and cost of third parties contracted to help resolve an unplanned outage.

Indirect Cost - The amount of time, effort, and other organizational resources spent, but not as a direct cash outlay. Indirect costs would include the time to recover lost or damaged mission-critical data as well as user and IT productivity loss.

Opportunity Cost - The cost associated with lost business opportunities as a result of reputation diminishment after the outage. Opportunity costs would include lost revenues and related business consequences. Lost revenues come from the current and potential customers’ inability to access core systems like VoIP or email during the outage period. The consequences a business could face due to an outage would be reputational damages, customer churn, and loss of business opportunities.

Avoid scenarios where your staff indicate, “The server(s) is down! The Internet is down,” and then wondering what other fallout occurred due to a network failure. There are different types of redundancy options that are available for your business and in your provider’s network; you just have to determine which one would be the right fit for your network. We have included some for you to review:

Common Redundancy Models

Multiple Spanning Trees (MST)

MST supports load-balancing capability while still allowing for scalability. It enables the designated administrator to plan out a random number of VLANs to one MST instance. As a result, there are the least number of instances essential to satisfy a design.

Ring Network

A ring network is a type of topology in which nodes are connected in a closed loop (ring) configuration. Similar to a bus network, a ring network has one extra link connecting the last switch to the first switch and where each switch supports a redundancy protocol. Ring protocols typically disable one link to stop messages from circulating the network. If the link in the ring fails, then the backup link is enabled to restore the network.

Diverse Trunking

Diverse trunking provides communications and network access between two switching centers. A trunk can consist of multiple wires, cables, or fiber optic strands bundled together in a single physical sheath. Typically, network redundancy is accomplished through the addition of substitute network paths from a secondary physical cable which are implemented through redundant standby routers and switches. When the primary path is unavailable, the alternate path can be instantly deployed to ensure minimal downtime and continuity of network services.

Multi-Protocol Label Switching (MPLS)

A MPLS cloud is a meshed and redundant network in which data packets are assigned labels that specify the paths or routes for transmission across the network. Label Switch Routers (LSRs) read these short labels and forward the data packets according to these instructions. This enables very high-speed packet switching and redundancy through the core MPLS network.

Having redundancy built into networks is essential for your business’s success. In the case of the Jacob K. Javits Convention Center (“Javits Center”), redundancy played a vital role in providing a secure connection to the entire facility. Read how a fully-redundant fiber solution like RCN’s Metro Ethernet played a fundamental role in minimizing business disruption in the event of a failure.