Continuing our discussion on 100G optical modules, let’s explore the essential 100G transmission standards—SR4, DR1, DR4, BiDi SR, LR4, CWDM4, SWDM4, ER, and ZR. These standards often cause confusion when selecting the right module for your needs. But don’t worry! By the end of this guide, we’ll demystify each standard and provide a clear, practical purchasing guide to help simplify your decision-making process.

100G Optical Modules’ Transmission Standards

1.100GBASE-SR4

• Transmission Distance: Up to 100 meters using OM4 multimode fiber.
• Transmission Mode: Multimode Fiber
• Wavelength: Operates at 850nm.
• Interface Type: Utilizes MPO/MTP connectors.
• Technology: This module employs four parallel lanes for both transmission and reception, with each lane capable of 25Gbps, resulting in a total bandwidth of 100Gbps.
• Application Scenarios: Ideal for short-distance interconnections within data centers. It is cost-effective, consumes low power, and is particularly suited for high-density interconnect environments.

2. 100G-SWDM4 (Short-Wavelength Division Multiplexing 4)

• Transmission Distance: Maximum of 150 meters (75 meters for OM3, 100 meters for OM4, and 150 meters for OM5).
• Transmission Mode: Multimode Fiber
• Interface Type: Typically uses an LC duplex interface.
• Wavelengths: Operates at 850nm, 880nm, 910nm, and 940nm.
• Transmission Method: Based on Short-Wavelength Division Multiplexing (SWDM) technology, it uses four different wavelengths within a single multimode fiber, enabling multiplexing and demultiplexing of multiple signals. Each wavelength supports 25Gbps, totaling 100Gbps.
• Application Scenarios: Ideal for short-distance high-speed connections between servers, switches, and storage in small to medium-sized data centers. It is also suitable for high-density computing environments that require space savings and simplified wiring.

3.100G BiDi SR

• Transmission Distance: Up to 100m
• Transmission Mode: Multi-mode fiber (MMF)
• Wavelength: 850 nm and 900 nm
• Interface Type: LC duplex connector.
• Transmission Technology: The module is designed for bidirectional data transmission over a single multimode fiber strand. It uses two optical lanes, each capable of 50Gbps, to transmit and receive data simultaneously
• Application Scenarios: Ideal for connecting switches and routers within the same data center or between closely located data centers

4. 100G-DR4

• Transmission Distance: Up to 500 meters using single-mode fiber.
• Transmission Mode: Single-mode Fiber
• Wavelength: Operates at 1310nm.
• Interface Type: Features an MPO-12 (8-core) connector.
• Technology: Utilizes four optical lanes, each transmitting at 25Gbps using PAM4 modulation, achieving a total of 100Gbps. It also supports breakout into four 25G or 100GBASE-DR1 connections.
• Application Scenarios: Primarily used for high-speed connections over medium to short distances within data centers. It is well-suited for fiber-to-the-server applications and can support large-scale distributed architectures, making it ideal for high-density interconnect requirements.

5. 100G-DR1

• Transmission Distance: Up to 500 meters using single-mode fiber.
• Transmission Mode: Single-mode Fiber
• Wavelength: Operates at 1310nm.
• Interface Type: Uses a Duplex LC connector.
• Transmission Method: Functions with a single-lane operation at 100Gbps using PAM4 modulation and employs single lambda technology, making it a popular choice for short-distance interconnections within data centers.
• Application Scenarios:
  • Intra-data center interconnects: Connecting racks or devices within large data centers.
  • Inter-data center links: Suitable for short distances between data centers within the same campus or region.
  • High-performance computing: Perfect for low-latency, high-throughput networks.

6. 100GBASE-CWDM4

• Transmission Distance: Up to 2 kilometers.
• Transmission Mode: Single-mode Fiber
• Wavelength: 1271nm, 1291nm, 1311nm and 1331 nm
• Interface Type: Features an LC duplex connector.
• Transmission Technology: Transmits four lanes of 25Gbps using Coarse Wavelength Division Multiplexing (CWDM) over a single fiber pair.
• Application Scenarios: Suitable for interconnections between data centers and within metropolitan areas over short distances, achieving high performance through efficient cost control.

7. 100GBASE-LR4

• Transmission Distance: Up to 10 kilometers using single-mode fiber.
• Transmission Mode: Single-mode.
• Wavelength: Uses four different wavelengths (1295nm, 1300nm, 1305nm, 1310nm) multiplexed using LAN WDM
• Interface Type: Employs an LC duplex connector.
• Transmission Technology: Utilizes 4x25Gb/s LAN WDM DML TOSA multiplexed into a single fiber pair.
• Application Scenarios: Ideal for campus networks and long-distance transmission (typically within 10 kilometers in metropolitan networks), widely used by carriers and large data centers.

8. 100GBASE-ER4

• Transmission Distance: Up to 40 kilometers 
• Transmission Mode: Single-mode Fiber
• Wavelength: 1295.56, 1300.05, 1304.58 and 1309.14 nm as members of the LAN WDM wavelength grid defined in IEEE 802.3ba
• Interface Type: Duplex LC duplex connector.
• Transmission Technology: The 100G QSFP28 ER4 optical module transmits across the four LAN WDM wavelength ranges. The optical signals are multiplexed through a WDM multiplexer and transmitted via LC duplex single-mode fiber patch cables.
• Application Scenarios: Suitable for long-distance transmission, commonly found in telecommunications operators, wide area networks (WAN), and metropolitan area networks (MAN).

9. 100G ZR4

• Transmission Distance: Up to 80 kilometers.
• Transmission Mode: Single-mode fiber.
• Wavelength: Operates at 1550nm.
• Interface Type: LC duplex connector.
• Transmission Technology: Converts input channels of 25Gb/s electrical data into 4 LAN WDM optical signals for fast networking. At the receiver, it demultiplexes a 100Gb/s optical input into four LAN WDM optical channels.
• Application Scenarios: Primarily used for wide area networks and ultra-long-distance transmission, suitable for carrier-grade large-scale interconnectivity across regions, as well as inter-metro connectivity and large-scale telecom deployments.

100G AOC and DAC Cable

100G AOC (Active Optical Cable) and DAC (Direct Attach Copper Cable) are two cabling solutions for high-speed data transmission. DAC is primarily utilised for very short-distance connections, offering an economical option for short-distance applications. In comparison, AOC is well-suited for long-distance transmission and provides enhanced flexibility, though at a higher cost.

100g DAC Module

How to Choose the Right 100G Optical Module for Your Network?

Selecting the appropriate 100G module for your network can significantly enhance performance and efficiency. Here’s a breakdown of recommended standards based on transmission distance, along with applicable scenarios and comparisons to help you make an informed decision.

1. Short-Distance Transmission Within Data Centers

Recommended Standards: 100GBASE-SR4 / 100GBASE-SWDM4/ 100G SR BiDi

Applicable Scenarios:

• High-bandwidth connections between servers and switches.
• Interconnections between racks within the data center, typically within 100 meters.

2. Medium-Distance Transmission (Up to 500 Meters)

Recommended Standards: 100GBASE-DR1 / 100GBASE-DR4

Applicable Scenarios:

• Connections between different floors or devices within the data center.
• Links between buildings within the same data center campus.

Comparison:

• 100GBASE-DR1: Features a single-mode, single-channel design with an LC interface, perfect for point-to-point connections that are easy to manage.
• 100GBASE-DR4: Employs a multi-channel design with an MPO interface, supporting high-density applications and the ability to split into four 25G links.

3. Medium-Long Distance Transmission (Around 2 Kilometers)

Recommended Standard: 100GBASE-CWDM4

Applicable Scenarios:

• Connections between data centers and campus networks.
• Inter-campus or short metropolitan area network connections.

Advantages:

• Utilizes CWDM technology, providing a cost-effective solution with solid mid-range transmission capabilities.

4. Long-Distance Transmission (Around 10 Kilometers)

Recommended Standard: 100GBASE-LR4

Applicable Scenarios:

• Data center interconnects within metropolitan area networks.
• Long-distance optical links for telecom operators.

Advantages:

• Employs single-mode fiber and LAN WDM technology, ensuring stable performance over longer distances.

5. Ultra-Long Distance Transmission (40-80 Kilometers )

Recommended Standards: 100GBASE-ER4 / 100GBASE-ZR4

Applicable Scenarios:

• Core layers of metropolitan area networks.
• Long-distance backbone network interconnects.

Decision Guide

1. Transmission Distance:

• For short distances (<100m), prioritize multimode modules (SR4/SR-BiDi/SWDM4).
• For medium to long distances (500m-10km), opt for single-mode modules (DR1/DR4/LR4).
• For ultra-long distances (>40km), choose ER4 or ZR4.

2. Network Architecture:

• For high-density needs (e.g., data center core switches), select QSFP28 form factor modules.
• For long-distance requirements (e.g., metro networks, backbone networks), consider CFP series form factor modules.

3. Budget Considerations:

• Multimode modules (e.g., SR4) are generally more affordable, making them ideal for short-distance connections on a budget.
• Long-distance modules (e.g., LR4/ER4) may have higher costs but offer reliable performance, justifying the investment for critical links.

Today, we’ve delivered a clear and comprehensive breakdown of the transmission standards for 100G optical modules. Our goal is to empower you with the insights needed to confidently choose the best standard for your needs. Let’s make your decision-making process as seamless as possible!

Question: Does Asterfusion offer 100G switches?

Asterfusion offers multiple models of 100G switches, all pre-installed with our self-developed enterprise SONiC distribution. These switches are suitable for various scenarios, such as campus networks and data centers. For more details, please refer to the following articles:

• 100G Data Center Switches: Driving the Future through Open Networking
• Asterfusion enterprise SONiC based 25G/10G open network switch overview

Reference:

https://www.researchgate.net/figure/shows-a-power-consumption-trend-for-MSA-CFP-and-CFP2-coherent-modules-over-time_fig2_352467831

40G and 100G Data Center Multimode Fiber Connectivity | Corning