Layer 2 vs Wavelength vs Dark Fiber
LAN2LAN Site Interconnect: Managed Ethernet vs Optical Transport vs Raw Infrastructure
Three transport models, one fiber network: managed Ethernet, dedicated wavelengths up to 400G, or unlit fiber under your control. All three run on our enterprise connectivity network.
Detailed Comparison Matrix
Technical and operational characteristics side-by-side
| Feature | Layer 2 Transport | Wavelength Service | Dark Fiber |
|---|---|---|---|
| Infrastructure Type | Managed Ethernet service (LAN2LAN) | Dedicated optical lambda | Unlit fiber strand(s) |
| Bandwidth Options | 100M, 1G, 10G, 100G (fixed) | 10G, 40G, 100G, 400G per lambda | Unlimited (customer equipment dependent) |
| Equipment Ownership | Carrier-owned CPE | Customer-owned DWDM/optics | Customer owns all active equipment |
| Network Management | Fully managed by carrier | Optical layer managed, customer manages L2/3 | 100% customer responsibility |
| Bandwidth Scalability | Service upgrade required (weeks) | Add lambdas or upgrade optics (days) | Instant (swap customer equipment) |
| Supported Protocols | Ethernet only: E-Line, E-LAN, EVPN, VPLS (802.1Q) | Any L2/3 protocol over DWDM or CWDM lambdas | Any protocol (no restrictions) |
| Typical Latency | 2-5ms (includes switching) | <0.5ms (optical only) | ~5μs/km (wire speed) |
| Redundancy Options | Carrier-provided diverse paths | Multiple lambdas on diverse fiber | Multiple fiber pairs (customer managed) |
| Service Level Agreement | 99.9-99.99% with service credits | 99.9% optical availability | Physical fiber only (no service SLA) |
| Deployment Time | 4-8 weeks (service provisioning) | 6-12 weeks (wavelength allocation + equipment) | 8-16 weeks (fiber build + equipment procurement) |
| Required Expertise | Basic networking (Ethernet) | Advanced (DWDM/optical) | Expert (full stack optical + networking) |
Layer 2 Transport
Managed Ethernet, turnkey deployment, carrier-owned CPE.
- Teams without in-house network engineering
- Predictable monthly OpEx, no CapEx
- Bandwidth under 10 Gbps per site
Wavelength Services
Dedicated optical lambdas, customer-controlled Layer 2/3.
- 10G-400G per location with in-house network expertise
- Multi-datacenter interconnect needing sub-ms latency
- Long-term deployments that justify equipment CapEx
Dark Fiber
Unlit strands, full customer control, unlimited scalability.
- Hyperscalers and cloud providers with massive bandwidth needs
- Financial institutions requiring ultra-low latency (under 100us)
- In-house optical engineering teams running over 10G sustained
Long-Term Cost Efficiency
High upfront equipment CapEx offset by low monthly fiber rental. Best economics for 10G+ bandwidth held over 5+ years.
Frequently Asked Questions
Technical questions about connectivity options
Yes, but it needs a parallel deployment to avoid downtime: bring up the new service, migrate traffic gradually, then decommission the old one.
Layer 2 Transport: typically metro, under 100km. Wavelength: CWDM about 80km, DWDM 2000km+ with amplification. Dark Fiber: unlimited with customer-provided amplifiers.
Layer 2: the carrier provides diverse routing. Wavelength: order multiple lambdas on diverse fiber. Dark Fiber: lease multiple fiber pairs on diverse routes and manage failover yourself.
The carrier repairs the physical fiber in every case. Layer 2 customers get carrier-managed failover per SLA. Wavelength customers may need to reconfigure their own equipment; Dark Fiber customers detect the outage and reconfigure equipment themselves.
Yes. Common pattern: Dark Fiber for primary datacenter interconnect, Layer 2 Transport for branch offices, Wavelength for mid-tier sites. Keep SLA management and monitoring consistent across all three.
Need Help Selecting Connectivity Infrastructure?
Our network architects can evaluate your bandwidth requirements, technical capabilities, and budget to recommend the optimal fiber solution for your organization.
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