Managed Ethernet is usually the simplest option when a project wants a carrier-operated private service. A wavelength suits high-capacity point-to-point transport where the carrier manages the optical layer. Dark fibre provides the most control and scalable capacity, but the client must provide and operate the active equipment. The right choice depends on capacity, route, operational capability, contract horizon and whole-life cost.
The basic difference
These products can all connect two locations, but responsibility sits in different places.
- Ethernet: the carrier delivers a managed Layer 2 service at an agreed speed.
- Wavelength: the carrier delivers a managed optical channel, usually at a high fixed capacity.
- Dark fibre: the carrier or infrastructure owner provides unlit fibre; the customer supplies the optics and operates the active layer.
Internet access is a separate requirement. A point-to-point Ethernet or wavelength does not provide internet unless it connects to an internet service elsewhere.
Product comparison
| Factor | Ethernet | Wavelength | Dark fibre |
|---|---|---|---|
| Typical management | Carrier managed | Carrier managed optical service | Customer manages active equipment |
| Capacity | Wide range, commonly sub-10G to 100G | Commonly 10G, 100G or 400G | Determined by fibre, optics and engineering |
| Customer control | Moderate | Higher service transparency | Highest |
| Operational burden | Lowest | Low to moderate | Highest |
| Scaling | Regrade or additional service | New or upgraded wavelength | Add or upgrade customer optics |
| Commercial model | Recurring managed service | Recurring high-capacity service | Lease, IRU or other asset-style arrangement |
When managed Ethernet is usually suitable
Ethernet is often appropriate when the project wants a defined private connection without operating an optical network. It is straightforward to specify and can include service monitoring, support and a clear demarcation.
Check whether the service is uncontended, how the carrier delivers it, the route used, latency expectations, frame-size support, interface and upgrade process.
When a wavelength is usually suitable
A wavelength is often used for high-capacity transport between data centres, carrier hotels, network POPs or operational sites. It can provide a cleaner high-speed handover than a packet-based managed service while leaving the optical engineering with the carrier.
Confirm protection options, route, optical interface, latency, performance monitoring, service restoration and whether the quoted service is genuinely dedicated end to end.
When dark fibre is usually suitable
Dark fibre can be attractive where the client needs control, multiple services, rapid capacity growth or a long-term strategic route. It may support several wavelengths over the same fibre pair.
It also transfers responsibility. The customer must design, fund and operate the optics, manage spares and monitoring, understand optical loss and maintain an effective fault process with the fibre provider.
How to decide
- Capacity and growthHow much is required now, and how quickly might it increase?
- Operational capabilityDoes the client want a managed service or control of the optical layer?
- Route availabilityWhich products are actually available over the required physical path?
- LifecycleIs this a short-term project need or a long-term strategic connection?
- Whole-life costInclude equipment, space, power, support, upgrades and termination exposure.
- ResilienceCan the chosen product be delivered over genuinely diverse infrastructure?
Frequently asked questions
Common questions
Is dark fibre always the best option for 100G or 400G?
No. A managed wavelength may be more efficient where the client does not want to operate optics or where dark fibre is not available on the required route.
Can Ethernet be used between data centres?
Yes. Managed Ethernet is widely used for private inter-site connectivity, subject to capacity, latency, route and service requirements.
Can several services run over one dark fibre pair?
Potentially, using suitable optical equipment and wavelengths. The design must consider fibre loss, distance, capacity, protection and operational support.
Can CROSS compare all three options?
Yes. CROSS can assess availability, route, capacity, construction, whole-life cost and operational implications before procurement.
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