10G Optical Module Guide: Compare LRM, SR, LR, ER, ZR for the Right Choice

As 10G Ethernet continues to be widely deployed in data centers, enterprise networks, and telecom infrastructures, choosing the right 10G optical module is critical for performance, cost control, and long-term scalability.

Among the most common options are 10G SR, LRM, LR, ER, and ZR modules.
Although they all support 10Gbps transmission, their fiber type, distance, wavelength, and application scenarios are very different.

This guide explains each type in a clear and practical way—helping you make the right choice for your network.

What Is a 10G Optical Module?

A 10G optical module (also called 10G transceiver or SFP+ module) converts electrical signals into optical signals for high-speed data transmission over fiber optic cables.

Typical applications include:

• Data center interconnections

• Enterprise core and aggregation networks

• Telecom and metro networks

• Cloud and AI infrastructure

Overview: 10G Optical Module Types Comparison

1. 10G SR Optical Module (Short Reach)

10G SR is the most commonly used 10G module in data centers.

Key Features

• Wavelength: 850nm

• Fiber: Multimode fiber (OM3 / OM4)

• Distance:

• Up to 300m on OM3

• Up to 400m on OM4

Typical Applications

• Data center switch-to-switch links

• Server-to-switch connections

• High-density short-distance deployments

Why choose SR?
✅ Lowest cost
✅ Low power consumption
❌ Limited distance

2. 10G LRM Optical Module (Long Reach Multimode)

10G LRM was designed to extend 10G transmission over existing legacy multimode fiber.

Key Features

• Wavelength: 1310nm

• Fiber: Multimode fiber (OM1 / OM2 / OM3)

• Distance: Up to 220m

Typical Applications

• Upgrading old data centers without replacing MMF

• Enterprise networks with legacy cabling

Why choose LRM?
✅ Works on old MMF
❌ Higher cost than SR
❌ Becoming less common in new deployments

3. 10G LR Optical Module (Long Reach)

10G LR is the standard choice for single-mode 10G transmission.

Key Features

• Wavelength: 1310nm

• Fiber: Single-mode fiber (SMF)

• Distance: Up to 10km

Typical Applications

• Campus networks

• Metro Ethernet

• Data center interconnection (DCI)

Why choose LR?
✅ Excellent balance of cost and distance
✅ Very common and widely supported

4. 10G ER Optical Module (Extended Reach)

10G ER is used when transmission distance exceeds 10km.

Key Features

• Wavelength: 1550nm

• Fiber: Single-mode fiber

• Distance: Up to 40km

Typical Applications

• Long-distance enterprise links

• Metro and access networks

• Service provider infrastructure

Why choose ER?
✅ Long-distance capability
❌ Higher cost and power consumption

5. 10G ZR Optical Module (Z Reach)

10G ZR supports ultra-long-distance transmission and is commonly used in telecom networks.

Key Features

• Wavelength: 1550nm

• Fiber: Single-mode fiber

• Distance: 80km or more (depending on link budget)

Typical Applications

• Telecom backbone networks

• Long-haul fiber links

• Critical infrastructure

Why choose ZR?
✅ Maximum distance
❌ Highest cost
❌ Overkill for most enterprise networks

How to Choose the Right 10G Optical Module

Ask these key questions before selecting a module:

1. What is the required transmission distance?

2. Which fiber type is already installed (MMF or SMF)?

3. Is cost or future scalability more important?

4. Is the module compatible with your switch brand?

In many cases, choosing a longer-distance module than necessary increases cost, power consumption, and link instability.

Compatibility Matters

Modern networks often use third-party compatible optical modules to reduce cost while maintaining performance.

High-quality compatible 10G modules:

• Fully support major brands (Cisco, Arista, Juniper, Huawei, HPE, etc.)

• Are MSA-compliant and tested for interoperability

• Offer significant cost savings without sacrificing reliability

Conclusion

Each 10G optical module type—SR, LRM, LR, ER, and ZR—is designed for a specific scenario.
Understanding their differences helps you optimize network performance, cost, and reliability.

Choosing the right module is not about using the longest distance—but the most appropriate one.