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Cellular Failover

Ensuring Always-on Connectivity — Automatically

When people walk into a movie theater to purchase a ticket, they simply take for granted that the transaction will go through. And it usually does — but not always.

Business Impact

Wired network failures do happen, and they can be the result of any number of causes, from a construction crew accidentally cutting a communications line, to weather events, to human error in network operations. When these failures do occur, enterprises that rely on their Internet connections for productivity, business operations and transactions can grind to a halt.

During communication outages, businesses can lose critical in-transit data, and business operations can be completely arrested. Negative impact on a business can add up quickly in lost business and productivity. Wireless network failover ensures business operations can continue — reducing risk and providing quick recovery and peace of mind.


What Is Failover?

Failover is a mechanism for automatically switching to a redundant standby network connection in the event the primary connection fails. When the primary wired connection is disrupted, failover instantly redirects requests from the primary to the secondary connection, which maintains connectivity until the primary connection is back online. Dependable failover is a necessity for any business requiring a secure, “always on” connection, for applications such as for credit card processing or automation monitoring and control.

Wired or Wireless Failover?

Failover Diagram

Some companies try to back up their primary wired connection with a second wired line. Unfortunately, unless they’re installed at the same time as the primary wired service, wired failover solutions can be very expensive. Worse, wired backup provides little improvement in reliability, since backup wiring most often follows the same route to customer sites as primary wiring, and is subject to the same environmental risks and potential damage from severe weather, accidents or other events.

Benefits of Cellular Backup

In recognition of the risks of wired backup, many companies are turning to wireless cellular solutions for backup connectivity. When the wired system fails, the connections automatically failover to a cellular LTE connection, ensuring that Internet connectivity and vital business operations remain uninterrupted.

Wireless failover allows business communications to quickly and seamlessly switch from a disrupted connection to an always-on high-speed connection that is independent of the primary wired line. When paired with out-of-band management, automated cellular failover can virtually eliminate business downtime and truck rolls.

The advantages of cellular failover include:

  • Reliability – The availability of LTE networks used for cellular failover is now reaching 99.99%. With the advent of 5G, reliability — and speed — will continue to advance.
  • Redundancy – Cellular failover enables devices to switch between different multiple wireless carriers for greater redundancy, while controlling costs.
  • Security – A stateful firewall with best-practice configurations, automated patches and updates provides a high level of security.
  • Management – With a cellular connection, there’s no need to replace existing infrastructure, like routers, firewalls or SD-WAN appliances. A serial port for out-of-band management means you can configure and troubleshoot other devices remotely even when the primary connection fails.

In addition, many companies are discovering that cellular is attractive not only as a failover option, but as a cost-effective primary connection as well, especially in remote locations. They are empowered to extend their corporate network and security standards virtually anywhere without the use of leased communication lines.

Cellular Failover Solutions from Digi

With more than 15 years building cellular solutions, Digi has long recognized the exceptional advantages of cellular communications for customers demanding always-up, always-on connectivity, and Digi offers numerous connectivity solutions to meet those needs. Here are a few examples:

Digi EX15 Cellular extender The Digi EX15 LTE cellular extender can be used as a network failover solution to ensure business continuity, or as a primary LTE data connection. The Digi EX15 also includes a serial port that can be used for remote, out-of-band management.
Digi EX12 Cellular Extender The Digi EX12 cellular extender is designed for enterprise applications requiring reliability and redundancy, with Cat 4 speeds, dual SIMs and patented Digi SureLink® for always-on connectivity.
Digi TX54 Cellular router The Digi TX54 router, with a FirstNet Ready™ option for emergency responders, provides highly available connectivity for mobile applications such as city transportation systems, ambulance, police and fire with dual-SIM failover.
Digi IX20 Cellular router The Digi IX20 cellular router is a compact and economical cellular routing platform for industrial environments that supports redundant connectivity with dual SIMs and Digi SureLink®.
Digi SureLink Technology Digi SureLink is a key component of the Digi cellular failover platform. It offers dual-SIM capability to provide another layer of failover redundancy, so that if one SIM card in the router cannot communicate with the primary wireless network, the second SIM will automatically switch to a secondary carrier to establish and maintain a connection with the backup wireless network. It provides always-up, always-on connectivity by sending and receiving keep-alive data packets at configurable intervals to and from Digi routers to detect network failures.
Digi Remote Manager® IoT software Digi Remote Manager is device security and management platform that enables network administrators to monitor their connection status with real-time alerts, reports and statistics. Digi Remote Manager is PCI-compliant, and provides reliable out-of-band management access to Digi devices through a unified interface.


Wired and wireless network systems need to work in tandem to provide uninterrupted network connectivity. While wired systems still support the bulk of network traffic, secure, reliable failover solutions are essential to making sure that business operations can always remain up and running, productive and profitable.