Dual WAN Routers for Business in Australia: How They Work and What to Look For

A single internet connection is a single point of failure. For most Australian businesses, an NBN or fibre outage means staff cannot access cloud applications, EFTPOS terminals go offline, VoIP phones stop working, and productivity halts until the connection is restored. The fix is straightforward: a dual WAN router with a backup internet connection. This article explains how dual WAN routers work, what to look for when choosing one, and which specific products are worth considering for Australian businesses.

What Is a Dual WAN Router?

A dual WAN router is a network device with two separate wide area network (WAN) ports, each of which can be connected to a different internet service. Where a standard business router has a single WAN port connecting to an NBN modem or fibre handoff, a dual WAN router accepts two separate connections and manages them intelligently.

The two connections can operate in one of two modes: failover or load balancing. In failover mode, one connection acts as the primary and the second sits dormant, activating automatically the moment the primary fails. In load balancing mode, traffic is distributed across both connections simultaneously. Most business-grade dual WAN routers support both modes and allow the administrator to choose based on their requirements.

The practical result is the elimination of the single point of failure that exists when a business relies on one internet connection. When the primary NBN connection goes down — whether due to a line fault, network outage, or hardware failure at the exchange — the router detects the failure and switches all business traffic to the secondary connection, typically a 4G or 5G mobile data service. This switchover happens automatically, without any intervention from the business owner or staff.

For a broader look at why internet redundancy matters for Australian businesses, see our guide to business internet redundancy and failover.

Failover vs Load Balancing: Understanding Both Modes

Failover Mode

In failover mode, one WAN port is designated as the primary connection. The router continuously monitors whether the primary connection is working by running active health checks — typically sending ping requests to external IP addresses and verifying that responses are received. When the primary connection fails these health checks, the router automatically reroutes all traffic to the secondary WAN.

The switchover time on modern routers is typically between 10 and 60 seconds, depending on the router model and how the health checks are configured. During this window, active internet sessions will be interrupted. Applications that rely on persistent connections — VoIP calls in progress, active VPN tunnels, some database connections — will notice the interruption and will need to reconnect once the secondary connection is active.

For most businesses, this brief interruption is far preferable to an outage of indefinite duration. A VoIP call that drops and can be redialled in under a minute is a much better outcome than a phone system that remains offline for hours. The secondary connection then remains active until the primary recovers, at which point the router can automatically switch back.

Load Balancing Mode

Load balancing mode operates differently. Rather than holding the secondary connection in reserve, the router actively uses both WAN connections simultaneously, directing sessions or individual packets across both links according to an algorithm designed to optimise throughput and utilise available bandwidth.

The theoretical benefit is twofold: aggregate bandwidth increases because both connections are in use, and resilience is inherent because if either connection fails, traffic continues on the remaining one. In practice, load balancing is more complex to configure correctly. Applications that are sensitive to IP address changes mid-session — certain banking portals, some VPN configurations, and payment systems — can experience problems when consecutive packets within the same session are routed through different WAN connections with different public IP addresses.

For this reason, most Australian businesses use failover mode for its simplicity and reliability. Load balancing is better suited to technically capable businesses with a specific need to aggregate bandwidth across two connections, and is best configured with guidance from an experienced IT provider. For more on 4G failover as a backup solution, see our article on 4G failover and backup internet for Australian businesses.

How the Router Detects a Connection Failure

This is one of the most important technical considerations when choosing a dual WAN router, and it is frequently misunderstood.

A basic router detects a WAN failure only when the physical port goes down — that is, when the cable is disconnected or the modem signals a loss of synchronisation. This works for obvious physical failures. However, many real-world internet outages are what engineers call "grey failures": the physical link remains up, the modem is synchronised, and the router sees a healthy Ethernet connection — but traffic is not actually passing to the internet. The NBN network may have an upstream fault, DNS resolution may have stopped working, or routing at the ISP level may be broken. A router that monitors only the physical link will not detect these grey failures and will not trigger failover, leaving the business without internet despite the backup connection sitting idle.

Quality dual WAN routers use active health checks to solve this problem. Rather than relying on the physical link state, the router continuously sends ping requests to known-reliable external IP addresses — commonly Google's public DNS server at 8.8.8.8 or Cloudflare's 1.1.1.1 — through each WAN connection and monitors whether responses are received. If a configurable number of consecutive pings fail within a configurable timeframe, the router declares that WAN connection as failed and triggers the switchover.

This is the behaviour required for reliable failover. When evaluating dual WAN routers, confirm explicitly that they support active WAN health monitoring with configurable ping targets and failure thresholds — not just physical link detection. Most business-grade routers from reputable vendors do support this, but it is worth verifying during the selection process.

WAN Port Types and Connection Options

Understanding what can be connected to each WAN port determines which failover configurations are possible for your business.

Ethernet WAN is the standard connection type used for NBN modem or NTD connections, dedicated fibre handoffs, and most fixed business internet services. The router's WAN port connects via Ethernet cable to the modem or network termination device provided by the ISP. This is the primary WAN connection for the vast majority of Australian businesses.

Cellular WAN via Ethernet is the most common approach for secondary connections. A 4G or 5G cellular router — a separate device with its own SIM card — connects to the dual WAN router's second Ethernet WAN port, presenting itself as a standard Ethernet internet connection. This approach is straightforward, flexible, and compatible with virtually all dual WAN routers.

Built-in cellular modems are found in some router models, most notably in the Peplink BR1 Pro series. These routers contain an integrated cellular modem with a SIM card slot, eliminating the need for a separate 4G device. This produces a cleaner, more compact installation and is particularly well-suited to businesses that want a single managed device.

USB WAN support is present on some routers, allowing a 4G USB modem to be plugged directly into a USB port as a backup WAN. This is less common in modern business configurations and generally less reliable than a dedicated Ethernet cellular connection.

Dual SIM configurations are available on some cellular routers and combined devices. Two SIM cards from different carriers can be installed, providing redundancy within the cellular backup itself. This is particularly useful in areas where one carrier has known reliability issues, or for businesses where even a brief loss of the backup connection during failover carries significant risk.

The most common Australian business configuration is an NBN fixed connection on Ethernet WAN port 1, paired with a 4G or 5G SIM on either a built-in cellular modem or an external cellular router connected to Ethernet WAN port 2. For more on 5G as a business backup option, see our guide to 5G backup internet for Australian businesses.

Specific Products for Australian Businesses

The following products represent the main categories relevant to Australian SMB and mid-market buyers. Pricing is approximate Australian retail as at the time of writing and will vary by supplier.

Draytek Vigor Series

Draytek is one of the most widely deployed router brands in the Australian SMB market, and for good reason. The Vigor 2865 and Vigor 2927 series offer dual WAN connectivity — typically one Ethernet WAN port combined with either a second Ethernet WAN port, a VDSL/ADSL port, or optional 4G/LTE USB modem support — at a competitive price point of approximately $300 to $800 depending on the model and configuration.

Draytek's failover detection is reliable and well-regarded. The web-based management interface is comprehensive and accessible to competent non-specialist users, though more advanced configurations benefit from IT assistance. Active WAN health monitoring is supported with configurable ping targets. QoS rules can be applied to prioritise critical traffic across WAN connections.

The main limitation of the Draytek range for failover use cases is that the built-in cellular modem options are less extensive compared to Peplink. Most Draytek failover deployments use a separate 4G router on the second Ethernet WAN port, which is a straightforward and effective configuration.

Draytek is a strong choice for businesses that want a proven, cost-effective router capable of reliable failover, particularly where IT support is available for initial setup.

Peplink Balance Series

Peplink manufactures routers built specifically for multi-WAN scenarios, and their Balance and BR series are among the most capable options available to Australian businesses. The Balance One and Balance Two support multiple Ethernet WAN ports with excellent load balancing and failover management. The BR1 Pro integrates a cellular modem directly, making it a self-contained failover solution with a single device.

The standout feature of Peplink routers for VoIP-dependent businesses is SpeedFusion, Peplink's proprietary WAN bonding technology. SpeedFusion allows VPN tunnels to span both WAN connections simultaneously, so that if one connection fails, the VPN — and the VoIP traffic it carries — does not drop. Instead, it seamlessly continues through the remaining connection. For businesses where uninterrupted phone calls are critical, this capability is difficult to replicate with other products.

Peplink routers are more expensive than Draytek, typically ranging from $600 to $2,000 or more depending on the model and whether SpeedFusion licensing is included. They are more complex to configure and are best set up by an experienced IT provider. However, for businesses with demanding VoIP reliability requirements or a need for true load balancing across multiple WAN connections, the additional investment is well justified.

Fortinet FortiGate

FortiGate devices from Fortinet occupy the enterprise end of the market and combine multi-WAN management with a full SD-WAN and next-generation firewall feature set. For businesses that need a single device to serve as both the primary firewall and a sophisticated multi-WAN manager, FortiGate is a leading option.

SD-WAN capabilities in FortiGate devices allow granular control over how traffic is distributed across WAN links, including application-aware routing, SLA monitoring, and automated failover based on performance thresholds. Configuration and ongoing management typically require an IT professional or managed service provider familiar with the FortiGate platform.

Pricing starts at approximately $800 and extends to $3,000 or more for models suited to larger businesses, with ongoing licensing costs for security features. FortiGate is best suited to businesses with existing IT management or a managed services provider relationship, and is overkill for smaller businesses that simply need reliable NBN-plus-4G failover.

Ubiquiti EdgeRouter

Ubiquiti's EdgeRouter series offers cost-effective hardware capable of multi-WAN failover, and the devices are popular among technically capable users and small IT consultancies. The hardware is well-built and the underlying routing software is powerful.

The practical limitation for most business deployments is that advanced failover configuration on EdgeRouter devices requires comfort with the command line. There is no point-and-click failover wizard comparable to those on Draytek or Peplink. For businesses with in-house IT staff who are familiar with Linux-based networking, EdgeRouter is a cost-effective option. For businesses without technical staff, it is generally not recommended.

For a broader comparison of business router and firewall options, see our guide to business routers and firewalls in Australia.

QoS and Traffic Prioritisation Across WAN Links

When a dual WAN router switches from a primary NBN connection to a secondary 4G connection, available bandwidth typically decreases — often significantly. An NBN 100 plan providing 100 Mbps download may fail over to a 4G connection delivering 20 to 40 Mbps, depending on signal conditions and network load at the time of the outage.

At reduced bandwidth, it becomes important that the most critical business traffic receives priority over less critical usage. This is the role of QoS, or Quality of Service — a set of rules applied by the router that govern how available bandwidth is allocated between different types of traffic.

For most businesses, the QoS priority order during failover should be roughly as follows. VoIP calls require very little bandwidth — approximately 100 to 200 kilobits per second per active call — but they are sensitive to latency and packet loss, so they must receive guaranteed priority. EFTPOS terminals require minimal bandwidth and must not be disrupted. Critical business applications — cloud accounting, CRM, email — should receive the next tier of priority. Lower-priority traffic like software updates, cloud file synchronisation, and general web browsing should be deprioritised or bandwidth-limited during failover, as these can consume large amounts of bandwidth without any immediate business impact.

On Draytek routers, QoS is configured under the Bandwidth Management section of the web interface. Traffic can be classified by application type, IP address range, or port number, and assigned to priority bands. On Peplink routers, QoS is handled through the Traffic Prioritisation settings, where application categories can be assigned to high, medium, or low priority tiers.

The specific configuration will vary depending on the applications a business uses. Businesses running a hosted VoIP service should confirm with their VoIP provider which ports and protocols need prioritisation. For guidance on VoIP bandwidth requirements, see our article on VoIP bandwidth requirements for Australian businesses.

Data SIM Planning for Failover Use

A 4G or 5G SIM installed in a failover router is dormant during normal operation — while the primary connection is working, the SIM uses no data. The data usage only begins when a failover event occurs and all business internet traffic routes through the mobile connection.

This matters for SIM plan selection. During a failover event, data consumption can be substantial. A business with fifteen staff members actively using cloud applications, video conferencing, and web browsing over a four-hour outage could easily consume between 20 and 50 GB of data, depending on usage patterns. A consumer SIM plan with a 10 GB monthly allowance would be exhausted rapidly.

For business failover routers, a dedicated business data SIM is strongly recommended over a consumer SIM for several reasons. Business SIMs from major Australian carriers — Telstra, Optus, and Vodafone all offer business data plans — typically carry higher network priority than consumer SIMs during periods of congestion. During an outage scenario, when many people in the affected area may simultaneously attempt to use mobile data, a business-priority SIM is more likely to maintain consistent throughput.

Some carriers offer plans specifically designed for IoT and failover use cases, which charge only when data is used rather than a flat monthly rate. These can be cost-effective for businesses where failover events are infrequent. However, if your business experiences regular NBN instability, a plan with a generous included data allowance will be more predictable.

At minimum, a failover SIM plan should include at least 50 GB per month of data, and ideally 100 GB or more for businesses with a larger number of staff. The plan should be a business-grade service on a carrier whose network provides strong coverage at your premises — verify signal strength for each carrier before committing.

Installation and Configuration

A dual WAN router sits between the internet connections and the business's internal network. In a typical installation, the NBN modem or NTD connects to WAN port 1, and the 4G cellular router or modem connects to WAN port 2. The router's LAN port connects to the business's internal switch, which distributes connectivity to workstations, phones, and wireless access points.

The configuration process covers several steps. First, the primary WAN connection is configured with the correct connection type and any authentication credentials required by the ISP. Second, the secondary WAN connection is configured and verified as functional. Third, health check settings are established — the router should be configured to ping at least two external addresses (such as 8.8.8.8 and 1.1.1.1) and declare the WAN failed only if consecutive pings to both targets fail, to avoid false failover triggers. Fourth, the failover threshold is set — typically two to five consecutive failures over a 10 to 30 second period. Fifth, QoS rules are applied to prioritise critical traffic.

Testing failover before relying on it is essential. The correct approach is to deliberately unplug the primary WAN connection and observe the router's behaviour: the health checks should fail, the secondary WAN should activate, and critical applications should resume functioning within the configured switchover window. Test VoIP by making a call during the failover event. Test EFTPOS if applicable. Document what you observe.

Scheduled failover testing on a quarterly basis is a reasonable minimum. Failover systems that are installed and never tested can fail silently — a secondary SIM plan may have lapsed, a router firmware update may have altered a setting, or the cellular signal may have degraded since installation. Quarterly testing catches these issues before an actual outage does.

How Pickle Can Help

Pickle supplies and configures dual WAN routers for Australian businesses as part of its managed business internet service. Whether you are evaluating the right router for your situation, need a 4G or 5G backup SIM on a business data plan, or want ongoing support for your internet infrastructure, Pickle can assist.

Pickle's team can assess your business's requirements — primary connection type, appropriate router model, backup SIM carrier selection, QoS configuration for VoIP — and provide a complete solution with professional installation and configuration. Ongoing support means that if your primary connection fails and your backup activates, you have a team to call.

To discuss dual WAN router options for your business, call 1300 688 588 or email [email protected].

Frequently Asked Questions

Q: What is the difference between dual WAN failover and load balancing?

A: Failover mode designates one internet connection as primary and the other as a standby. The standby connection activates automatically if the primary fails, and traffic returns to the primary once it recovers. Load balancing mode uses both connections simultaneously, distributing traffic across them to increase aggregate bandwidth and provide resilience. Failover is simpler to configure and is more predictable for most business applications. Load balancing provides greater performance when both connections are healthy but requires more careful configuration to avoid problems with applications that are sensitive to having their traffic split across connections with different public IP addresses.

Q: How quickly does a dual WAN router switch to the backup connection?

A: On most modern business-grade dual WAN routers, the switchover occurs within 10 to 60 seconds of the primary connection failing its health checks. The exact time depends on the router model and how the health check intervals and failure thresholds are configured. A shorter detection window means faster switchover but also a higher risk of false triggers from temporary network fluctuations. A common configuration is to trigger failover after three to five consecutive failed health checks at 10-second intervals, which produces a switchover time of 30 to 50 seconds in practice.

Q: Will my VoIP calls be interrupted during a failover event?

A: In most standard failover configurations, a VoIP call in progress at the moment of failover will be dropped, because the IP session is interrupted when traffic moves to the secondary WAN connection. The call will need to be redialled once the secondary connection is active, which typically takes under a minute. If uninterrupted calls are a hard requirement, Peplink's SpeedFusion bonding technology can maintain active VoIP sessions across a WAN switchover by tunnelling traffic across both connections simultaneously. This is the most effective technical solution for businesses where dropped calls are not acceptable.

Q: Do I need a special SIM card for a business failover router?

A: A standard consumer SIM will work in a failover router, but a dedicated business data SIM is strongly recommended. Business SIMs carry higher network priority than consumer SIMs during periods of network congestion — which is precisely when you are most likely to need your failover connection, since an NBN outage may prompt others in your area to fall back to mobile data simultaneously. Business SIMs also typically offer better data inclusions and more predictable billing for the type of irregular, high-volume usage that characterises a failover event. Ensure the plan includes sufficient data to cover your business's needs during a multi-hour outage.

Q: Can I use a Draytek router for dual WAN failover with a 4G backup?

A: Yes. Draytek Vigor routers in the 2865 and 2927 series support dual WAN failover with a 4G backup connection. The most straightforward configuration is to connect a 4G cellular router (providing its internet connection as an Ethernet output) to the second WAN port on the Draytek. Some Draytek models also support a 4G USB modem plugged directly into the router's USB port as a backup WAN. Active health check monitoring is supported on Draytek routers, which means the router will detect grey failures — outages where the physical link is up but traffic is not passing — and trigger failover correctly. Draytek routers are a cost-effective and well-supported choice for Australian SMBs seeking reliable NBN-plus-4G failover.