Bonded FTTC for Business: Dual Line Fibre Broadband Guide

FTTC — fibre to the cabinet — is one of the most widely available business broadband technologies in the UK. The majority of commercial premises can get FTTC, typically delivering 40–80Mbps download and 10–20Mbps upload on a single line. For businesses that need more capacity without the cost and lead time of a leased line, bonded FTTC offers a useful step up.

How Bonded FTTC Works

Bonded FTTC provisions two separate FTTC circuits at your premises — each using its own physical telephone line running from the street cabinet to your building. A bonding router connects to both circuits simultaneously and distributes outbound and inbound traffic across both active lines.

The key distinction between basic load balancing and true bonding is how traffic is handled. Load balancing sends entire sessions (such as a web browsing session or a file download) down one line or the other, alternating between them. True bonding aggregates both circuits into a single logical pipe and can direct portions of individual streams across both lines, delivering closer to the combined theoretical throughput.

For business use cases — Teams calls, cloud applications, remote desktop sessions — the practical difference between well-configured load balancing and full aggregation is often modest. The resilience benefit is more universally significant: when one line fails, the other carries all traffic automatically.

Speeds You Can Expect

The actual speeds achievable depend on your distance from the street cabinet. FTTC speeds degrade with distance — the fibre runs to the cabinet but the final section uses copper, and performance drops over longer copper runs.

• Close to cabinet (<200m copper run): 76–80Mbps download per line. Bonded pair: up to 150–160Mbps aggregate.
• Medium distance (200–500m): 50–70Mbps per line. Bonded pair: 100–140Mbps.
• Longer copper run (>500m): 30–50Mbps per line. Bonded pair: 60–100Mbps.

Upload speeds are typically 8–20Mbps per line depending on distance and provider. A bonded pair provides 16–40Mbps combined upload — meaningfully better than a single FTTC line, though still asymmetric.

Costs

Bonded FTTC pricing varies by provider and location but typically falls into the following range for a 24 or 36-month managed contract:

• Bonded FTTC pair (managed service, includes bonding hardware): £90–£160/month
• Bonded FTTC pair (circuits only, your own bonding router): £55–£100/month for the two circuits

If you supply your own bonding router, budget approximately £350–£700 for a suitable device such as a Draytek Vigor 2865 or Peplink Balance 20X. Some providers include compatible hardware as part of a managed bonding service, which typically adds £20–£40/month but removes the hardware management burden.

Bonded FTTC vs a Single FTTC Line

The case for upgrading from a single FTTC to a bonded pair is strongest when:

• Your team regularly experiences slowdowns during peak hours as the single line is saturated
• You have experienced FTTC faults and cannot afford any period of total connectivity loss
• You are running hosted VoIP and need more consistent bandwidth for concurrent calls
• You are adding staff and your current bandwidth per user is becoming inadequate

Bonded FTTC vs a Leased Line

FTTC, even when bonded, is a shared-access technology. During peak periods, the connection from the cabinet back to the exchange is shared with other broadband users, which can reduce performance below headline speeds. A leased line provides dedicated, uncontended bandwidth with guaranteed performance and a formal SLA.

Bonded FTTC suits businesses with 10–30 staff where internet reliability is important but not mission-critical. If your organisation has more than 30 staff or your business genuinely cannot function without internet connectivity, a leased line is the more appropriate and defensible investment.

What About FTTP?

If full fibre FTTP is available at your premises, a single FTTP circuit at 300–1,000Mbps will outperform bonded FTTC at a similar or lower cost. Before ordering bonded FTTC, check whether FTTP has been deployed in your area — AMVIA can check availability against your specific postcode across Openreach, CityFibre and alternative network providers.