Connecting Two 10G Ethernet Switches Over 100Km Fiber Using the OM3800 DWDM System

Introduction

As enterprise networks, data centers, and campus infrastructures continue to expand, organizations are increasingly challenged to connect geographically separated locations without compromising bandwidth, reliability, or scalability.

Standard 10G Ethernet optical modules are typically limited to transmission distances of up to 10 km or 40 km, making them unsuitable for long-distance interconnection between sites.

Dense Wavelength Division Multiplexing (DWDM) technology provides an efficient solution by enabling multiple optical signals to be transmitted simultaneously over a single pair of optical fibers.

Combined with optical amplification and dispersion compensation technologies, DWDM significantly extends transmission distance while maximizing existing fiber resources.

This case study introduces a 100 km point-to-point 10G DWDM solution based on the OM3800 DWDM Platform, demonstrating how two 10G Ethernet switches can be seamlessly interconnected through transparent optical transmission.

The solution supports four independent 10G Ethernet services, delivering an aggregated capacity of 40 Gbps while reducing fiber consumption and providing room for future expansion.

Customer Requirements

A customer needed to establish a high-speed connection between two sites located approximately 100 km apart.

Both locations had already deployed 10G Ethernet switches and wanted to extend their existing network without replacing the switching infrastructure.

The customer's primary requirements included:

• Connect two 10G Ethernet switches over 100 km of optical fiber
• Support four independent 10G Ethernet services
• Maximize utilization of existing fiber resources
• Ensure reliable and stable long-distance transmission
• Allow future service expansion without redesigning the network
• Maintain transparent Ethernet transmission without modifying existing network equipment

To meet these requirements, Olycom proposed a 40G DWDM point-to-point transmission solution utilizing the OM3800 optical transport platform.

Network Architecture

The solution adopts a classic point-to-point DWDM architecture between Site A and Site B.

At each site, the existing 10G Ethernet switch connects directly to the OM3800 10G OTU card using standard 10G grey optical modules.

The OTU card converts the client-side grey wavelengths into DWDM wavelengths before forwarding them to the 8-channel DWDM MUX/DEMUX module.

The multiplexed optical signal is then amplified by an EDFA Booster Amplifier, transmitted over approximately 100 km of single-mode fiber, compensated by a Dispersion Compensation Module (DCM), and amplified again by a Pre-Amplifier EDFA before reaching the remote site.

Finally, the remote OTU converts the DWDM wavelengths back into standard 10G Ethernet optical signals and delivers them directly to the remote 10G Ethernet switch.

Throughout the entire transmission process, the Ethernet switches operate normally without requiring any configuration changes or protocol conversion.

The DWDM system functions as a transparent optical transport layer between the two networks.

Solution Configuration

The deployed system consists of the following equipment at both sites:

This configuration supports four active 10G services while leaving four additional DWDM wavelengths available for future network expansion.

How the 10G Ethernet Switch Integrates with the DWDM System?

One of the biggest advantages of this solution is its seamless integration with existing Ethernet infrastructure.

Instead of replacing switches or upgrading network protocols, the customer simply connects each 10G Ethernet switch to the OM3800 platform using standard 10G SFP+ optical modules.

The DWDM platform then performs several optical transport functions:

• Optical wavelength conversion
• DWDM multiplexing
• Optical signal amplification
• Long-distance fiber transmission
• Dispersion compensation
• DWDM demultiplexing
• Optical wavelength restoration

Because the DWDM system operates entirely at the optical layer, it remains completely transparent to upper-layer Ethernet services.

From the perspective of the Ethernet switches, the remote switch appears to be connected through a standard optical link, even though the actual transmission distance reaches approximately 100 km.

This transparent architecture allows organizations to extend existing networks without changing switch configurations, routing policies, VLAN settings, or network management systems.

Optical Transmission Process

The complete transmission workflow is straightforward and highly efficient.

• The 10G Ethernet switch generates four independent 10G Ethernet services.
• Standard grey optical modules transmit the services to the OM3800 OTU card.
• The OTU converts each grey wavelength into a dedicated DWDM wavelength.
• The 8-channel MUX combines multiple wavelengths into a single optical fiber.
• The Booster EDFA increases optical power before long-distance transmission.
• Optical signals travel approximately 100 km through single-mode fiber.
• The DCM compensates chromatic dispersion accumulated during transmission.
• The Pre-Amplifier EDFA restores signal strength before reception.
• The DEMUX separates individual DWDM wavelengths.
• The OTU converts DWDM wavelengths back into standard grey optical signals.
• The remote 10G Ethernet switch receives all Ethernet services transparently.

This process ensures excellent optical performance while minimizing latency and maintaining Ethernet service integrity.

Technical Advantages

1. High Capacity Transmission

The solution supports four independent 10G Ethernet services with a total transmission capacity of 40 Gbps.

Additional DWDM channels remain available for future upgrades without replacing the existing platform.

2. Long-Distance Connectivity

By combining EDFA optical amplifiers and dispersion compensation modules, the system reliably supports transmission distances of approximately 100 km, making it suitable for metropolitan and regional backbone networks.

3. Efficient Fiber Utilization

Instead of deploying separate fiber pairs for each service, multiple 10G signals share a single fiber pair through DWDM technology, significantly reducing fiber infrastructure costs.

4. Transparent Network Operation

The DWDM platform performs optical transport only and does not alter Ethernet frames or higher-layer protocols.

Existing switches continue operating exactly as before, simplifying deployment and maintenance.

5. Flexible Expansion

The installed 8-channel DWDM MUX currently utilizes only four wavelengths, leaving spare channels available for future service growth. Customers can increase bandwidth without changing the optical transport infrastructure.

Typical Applications

This 10G DWDM solution is widely applicable across various industries where long-distance, high-bandwidth connectivity is required.

Typical deployment scenarios include:

• Enterprise campus interconnection
• Data Center Interconnection (DCI)
• Government private networks
• Financial institution backbone networks
• Healthcare networks
• Industrial automation systems
• Smart city infrastructure
• ISP metropolitan access networks
• University campus networks
• Energy and utility communication systems

In each of these environments, transparent DWDM transmission enables organizations to extend existing Ethernet networks while preserving investment in switching equipment.

Conclusion

This project demonstrates how the OM3800 10G DWDM System provides a reliable, scalable, and cost-effective solution for connecting two 10G Ethernet switches over 100 km of optical fiber.

By combining 10G OTU cards, 8-channel DWDM multiplexers, EDFA optical amplifiers, and Dispersion Compensation Modules, the solution delivers transparent optical transport with an aggregate capacity of 40 Gbps while significantly reducing fiber consumption.

Because the existing Ethernet switches remain unchanged, deployment is fast and straightforward, minimizing operational disruption and lowering implementation costs. Furthermore, the reserved DWDM wavelengths provide a clear migration path for future bandwidth expansion, making the solution suitable for growing enterprise networks, data centers, campus environments, and metropolitan communication infrastructures.

For organizations seeking a dependable 10G DWDM solution, a scalable 100 km fiber transmission system, or a practical method of connecting two 10G Ethernet switches over long distances, the OM3800 platform offers an ideal combination of performance, flexibility, and investment protection. This architecture not only addresses today's connectivity requirements but also establishes a solid foundation for future optical network expansion