Updated November 2026
The short version
- A backup line only helps if it does not fail for the same reason as the main line, so look for a different path and technology, not just a different bill.
- Failover is the automatic switch. A router can handle it, and SD-WAN also watches how each connection is performing.
- An SLA gives you commitments and service credits. It does not keep you online, which is why a second connection matters.
- Phones that run over the internet go down with it, so plan calls into the failover design and test it.
- Getting the primary line, or both lines, from one provider such as 5x5 means one team designs the failover and you have one number to call.
What internet backup and failover mean
Internet backup, or a redundant internet connection, is a second connection at your site that can carry traffic when the main one fails. Failover is the switch itself: the equipment notices the main line has a problem and sends traffic over the other one.
You need both. A second line with no automatic failover means someone has to move cables or change settings during an outage. Failover with no truly separate second line can switch to a connection that has failed for the same reason.
Why the second connection should take a different path
CISA defines route diversity as routing communications between two points over more than one physical path with no common points. That is the goal for a backup connection: no shared cable, conduit, building entry point or carrier route that one event could cut.
Buying from two providers does not guarantee it. CISA notes that an organization can use two carriers and still have both services running in the same conduit, and FFIEC guidance points out that multiple carriers may rely on the same backbone.
- Confirm how each line enters the building and which route it takes. When 5x5 supplies both lines, we plan them on separate paths.
- Avoid two wired lines that share a conduit, a building entry point or the same carrier network.
- Prefer a different technology for the second line, such as a wireless connection next to a wired one.
- Put the router, SD-WAN device and switches on backup power, so a power cut in the closet does not take out both lines.
Common primary and backup pairings
- Fiber with fixed wireless
- How the paths differ: Fixed wireless does not depend on a cable in the street, so it takes a different path from wired lines
- SLA coverage at 5x5: Both can be SLA-backed; fixed wireless carries the same SLA as fiber
- Dual fixed wireless
- How the paths differ: Two fixed wireless connections, one primary and one secondary, with no cable in the street
- SLA coverage at 5x5: Both can be SLA-backed with the same SLA as fiber
- Fiber or dedicated internet with 5G or 4G LTE
- How the paths differ: Cellular uses a mobile network instead of a wired line
- SLA coverage at 5x5: The wired line can be SLA-backed; 5G and LTE are not covered
- Fixed wireless with 5G or 4G LTE
- How the paths differ: Two wireless connections over different networks, with no cable in the street
- SLA coverage at 5x5: Fixed wireless can be SLA-backed; 5G and LTE are not covered
- Two wired lines
- How the paths differ: Diverse only if the conduits, building entry points and carrier routes are confirmed separate
- SLA coverage at 5x5: Depends on each service
5x5 offers every connection type in this table, so you can run the primary line with us, or both. Dual fixed wireless is a strong primary and secondary setup. 5x5 fixed wireless is a primary enterprise internet solution with built-in redundancy, not just a backup. 5G and LTE can be a permanent primary connection or a backup. Which pairing fits depends on what is available at your building and whether you need an availability commitment on both lines.
Fiber and dedicated internetFixed wireless5G business internet
Why run the primary line, or both lines, with one provider
Path diversity comes from the route and the technology, not from the number of bills. Two providers can still share a conduit, while one provider can deliver two connections on separate paths, such as fiber with fixed wireless or dual fixed wireless.
With one provider on both lines, one team designs the connections and the failover, supports both, and takes the call when something breaks. There is no question of which provider to call during an outage.
- 5x5 for both lines: fiber with fixed wireless, dual fixed wireless, or either with 5G or LTE, with managed SD-WAN on top.
- 5x5 for the primary line: keep a connection you already have as the backup, and we design the failover across both.
- One US-based support team for every connection. During business hours, every ticket gets a first reply within 60 minutes. Outside business hours, including weekends and holidays, emergencies get the same 60-minute first reply.
Automatic failover with a router or SD-WAN
Both connections plug into one device at your site. A router with failover rules sends traffic over the main line and switches to the second line when the main one stops responding.
SD-WAN goes further. It checks how each connection is performing and sends traffic over the path that is working best, so it can move traffic when a line is failing or congested, not only when it is fully down. TechTarget describes automatic failover and redundancy across WAN connections as one of the core benefits of SD-WAN.
The failover device can become the weak point. If it fails or loses power, both connections go with it, so put it on backup power. With 5x5 managed SD-WAN, we monitor the device and both connections and handle changes.
Active/active vs active/standby, in plain words
There are two ways to run a second connection. CISA describes backup links that sit ready as standbys and links that carry traffic every day; both add redundancy.
Active/active
- Both connections carry traffic all the time
- SD-WAN spreads traffic across them and shifts it when one has a problem
- You use the bandwidth on both lines every day
- Problems with the second line show up early, because it is always in use
Active/standby
- The main connection carries everything
- The second connection waits until the main one fails
- A common way to use 5G or LTE as a backup line
- Needs regular testing, because a problem on an idle line can go unnoticed
What an SLA does and does not cover
A service level agreement sets measurable commitments for a connection and says what you receive if the provider misses them, usually a service credit on your bill. For SLA-backed services, we commit to at least 99.999% network availability, subject to the SLA.
- It does give you commitments in writing and a credit when a covered commitment is missed.
- It does not keep the office online during an outage, and a credit will not cover lost sales or productivity.
- It only covers the services named in it. At 5x5, fiber and fixed wireless can be SLA-backed; 5G and LTE are not.
- It does not fix a single point of failure at your site, such as one router, one power circuit or one building entry point.
A strong SLA on the main line and a second connection on a different path work together. Read the definitions and exceptions in the 5x5 SLA before you rely on the headline number.
Keeping phones working during an outage
Business VoIP and other cloud phone systems carry calls over your internet connection, so when the internet goes down, desk phones go with it. With failover in place, phones use whichever connection is working.
Expect a short interruption during the switch. TechTarget recommends measuring how long failover takes and how much traffic is lost when you force the main link to fail, and calls in progress may drop depending on the design.
- Include the phone system in the failover design, not just computers and Wi-Fi.
- Give staff a softphone app on their computers and smartphones, so they can take calls over another connection.
- Set up call forwarding or simultaneous ringing, so calls can reach mobiles or another location if the office is offline.
- Keep the network equipment your phones rely on running on backup power.
How to test failover
A backup that has never been tested is a guess. NIST contingency planning guidance says testing validates recovery capabilities, and Ready.gov notes that testing shows which parts of a plan will not work in practice.
- Unplug or disable the main connection during a quiet period and confirm traffic moves to the second line.
- Check what staff notice: web pages, video meetings, cloud apps and phone calls.
- Time the switch, then confirm traffic returns to the main line when it comes back.
- Confirm alerts reach the right people, so you know when the office is running on the backup.
- Repeat the test on a schedule and after any change to the network, the providers or the office.
Internet failover is one part of keeping the business running. For the wider plan, see how disaster recovery and business continuity fit together.
How 5x5 Telecom can help
5x5 can provide your primary connection, or both lines, and help design the failover configuration around your business needs. Our internet options include fiber, fixed wireless, 5G and 4G LTE, metro Ethernet and dedicated internet access, so the second line can use a different path and technology from the first.
We also provide managed SD-WAN, so the connections and the failover on top of them are planned and supported by one provider with one number to call. Installation typically takes days, not weeks or months. We confirm the schedule when we prepare your quote. Our support team is US-based. During business hours, every ticket gets a first reply within 60 minutes. Outside business hours, including weekends and holidays, emergencies get the same 60-minute first reply.
Related services and guides
Sources
- CISA: Ten keys to obtaining a resilient local access network
- CISA: Public safety communications resiliency, ten keys (PDF)
- FFIEC IT Examination Handbook: Telecommunications resilience
- NIST SP 800-34 Rev. 1: Contingency planning guide (PDF)
- TechTarget: What is SD-WAN?
- TechTarget: Steps for SD-WAN testing before deployment
- Ready.gov: Testing and exercises