Internet Bonding for Business: Combine Connections for More Speed

Internet bonding is a technique for combining multiple internet connections at either the hardware or network level to create a single, higher-performing composite link. For businesses that have outgrown a single broadband connection but find leased line costs or timescales prohibitive, bonding offers a middle path — more bandwidth, better resilience, and reasonable cost.

How Internet Bonding Works

At the core of any bonded setup is a device — either a dedicated bonding router or a cloud-based bonding platform — that manages traffic across multiple connections simultaneously. There are two main approaches:

Load Balancing

Load balancing distributes different network sessions (such as separate user browsing sessions or application connections) across the available circuits. Connection A handles some users, connection B handles others. If one circuit fails, sessions from that circuit are redistributed. This is technically simpler and available on most multi-WAN business routers.

True Packet-Level Bonding (Aggregation)

Packet-level bonding goes further, splitting individual data streams across multiple circuits at the packet level and reassembling them at a cloud concentrator or bonding endpoint. This delivers performance closer to the combined theoretical bandwidth — useful for large file transfers and download-intensive workloads. It requires a bonding platform (hardware and concentrator service) rather than a basic load-balancing router.

What Can Be Bonded?

Most internet connection types can be bonded together. Common combinations:

• Two FTTC lines: Widely available, cost-effective, good for doubling bandwidth and resilience
• Two FTTP lines: Higher performance ceiling, increasingly practical as FTTP coverage expands
• FTTC + 4G/5G: Hybrid approach combining fixed and mobile — useful for resilience or where fixed infrastructure is limited
• ADSL + ADSL (or VDSL): For premises without fibre, bonding multiple DSL lines extracts more from available copper
• Leased line + broadband: Primary leased line with bonded broadband failover — a resilience approach rather than performance aggregation

Bandwidth You Can Expect from Bonded Connections

In practice, bonded bandwidth is close to but not exactly the sum of the individual circuits:

• 2 x FTTC (80Mbps): Approximately 130–150Mbps download aggregate
• 2 x FTTP (300Mbps): Approximately 500–550Mbps download aggregate
• FTTC (80Mbps) + 4G (50Mbps): Approximately 100–120Mbps aggregate depending on mobile signal

True packet-level bonding approaches theoretical maximums more closely. Load balancing achieves effective aggregate bandwidth at the session level rather than the bit level.

Resilience: The Equally Important Benefit

Many businesses invest in bonding primarily for resilience rather than speed. With two independent circuits from different providers, a single provider outage — which would otherwise take down your entire connection — only removes half your bandwidth. Business continues, just at reduced speed.

For maximum resilience, the two circuits should come from different providers and, ideally, different physical paths to the exchange. This protects against ISP-level outages, local exchange faults and even physical cable damage affecting a single route.

Costs of Internet Bonding

Costs depend on the underlying circuits chosen and whether you use a managed bonding service or supply your own hardware:

• Two FTTC circuits (managed bonding service): £90–£160/month all-in
• Two FTTP circuits (managed bonding): £120–£220/month
• Hardware (Draytek, Peplink, etc.): £300–£800 one-off purchase if not included in a managed service
• Cloud bonding concentrator (if using packet-level aggregation): Sometimes included in managed service; standalone concentrators start around £20–£50/month

Internet Bonding vs a Leased Line

Bonding is not a replacement for a leased line — it is a different product with different characteristics. The key differences:

• SLA: Bonded broadband carries weaker SLAs than a leased line. Fault repair is measured in working days, not hours.
• Guaranteed bandwidth: A leased line provides 100% committed information rate. Bonded broadband uses contended shared-access circuits.
• Cost: Bonded broadband is almost always cheaper than a leased line of equivalent headline bandwidth
• Speed of installation: Broadband circuits install in days to weeks; leased lines take 60–90 days

AMVIA helps businesses assess whether bonded broadband or a leased line is the right choice based on their specific performance requirements, budget and risk tolerance. In some cases, the decision is clear; in others, a period on bonded broadband while a leased line order is in progress makes practical sense.