What is 100GBASE-ZR4?
100GBASE-ZR4 is a high-performance 100 Gigabit Ethernet optical transceiver designed for long-distance transmission over single-mode fiber. As the name suggests, “ZR4” indicates that this module operates over four lanes and supports distances up to 80 kilometers without the need for amplification. It typically complies with the IEEE 802.3ba standard and often follows a multi-source agreement (MSA) to ensure compatibility across vendors. The ZR4 module uses the QSFP28 form factor, which provides a compact and power-efficient footprint for modern high-density data center and metro networking equipment.
How Does 100GBASE-ZR4 Work?
The operation of the 100GBASE-ZR4 module is based on Coarse Wavelength Division Multiplexing (CWDM) with four parallel 25 Gbps optical lanes, each using a distinct CWDM wavelength. These wavelengths are multiplexed onto a single fiber strand for transmission and demultiplexed at the receiver side. The module typically employs electro-absorption modulated lasers (EMLs) for transmission and avalanche photodiode (APD) receivers with transimpedance amplifiers (TIAs) for detection, allowing high sensitivity over long distances. This architecture enables efficient transmission while maintaining low power consumption within the QSFP28 package.
Key Use Cases and Applications
100GBASE-ZR4 modules are ideal for long-distance point-to-point connections across metro or regional networks. A common deployment scenario is within data center interconnect (DCI) applications, where two data centers located tens of kilometers apart need to exchange massive amounts of data reliably. Another use case includes telecom backhaul and midhaul applications in 5G networks, where long-reach 100G links connect core routers and baseband units. ZR4 also fits well into campus network backbones or disaster recovery site connections, where fiber infrastructure exists but the distance exceeds the reach of LR4 modules.
Advantages Over Other 100G Transceivers
Compared to other 100G modules such as 100GBASE-LR4 and ER4, the ZR4 stands out due to its extended reach of up to 80 km, making it a more cost-effective option for long-haul links that do not justify the expense or complexity of coherent optics. While LR4 is limited to 10 km and ER4 reaches about 30–40 km, ZR4 fills a critical gap for medium to long-range transmission. Additionally, ZR4 still maintains the compact QSFP28 form factor, enabling high port densities and lower system power budgets compared to larger CFP or CFP2-based coherent solutions.
Considerations for Deployment
Despite its advantages, deploying 100GBASE-ZR4 requires careful planning. The optical link budget—determined by factors like fiber attenuation, connector losses, and dispersion—must fall within the module’s specifications. While most ZR4 modules support Forward Error Correction (FEC) on the host side to enhance signal integrity, ensuring host-device FEC compatibility is crucial. Fiber cleanliness and quality also play a role, especially over such long distances. Additionally, it's important to verify whether the receiving switch or router supports ZR4 modules, even if physically compatible, to avoid interoperability issues. The 100GBASE-ZR4 delivers a strong case for environments that need long reach without stepping into the world of expensive, power-hungry coherent transceivers. It fills a crucial gap in the 100G ecosystem and continues to gain traction as the demand for longer, more efficient fiber links grows.
What is 100GBASE-ZR4?
100GBASE-ZR4 is a high-performance 100 Gigabit Ethernet optical transceiver designed for long-distance transmission over single-mode fiber. As the name suggests, “ZR4” indicates that this module operates over four lanes and supports distances up to 80 kilometers without the need for amplification. It typically complies with the IEEE 802.3ba standard and often follows a multi-source agreement (MSA) to ensure compatibility across vendors. The ZR4 module uses the QSFP28 form factor, which provides a compact and power-efficient footprint for modern high-density data center and metro networking equipment.
How Does 100GBASE-ZR4 Work?
The operation of the 100GBASE-ZR4 module is based on Coarse Wavelength Division Multiplexing (CWDM) with four parallel 25 Gbps optical lanes, each using a distinct CWDM wavelength. These wavelengths are multiplexed onto a single fiber strand for transmission and demultiplexed at the receiver side. The module typically employs electro-absorption modulated lasers (EMLs) for transmission and avalanche photodiode (APD) receivers with transimpedance amplifiers (TIAs) for detection, allowing high sensitivity over long distances. This architecture enables efficient transmission while maintaining low power consumption within the QSFP28 package.
Key Use Cases and Applications
100GBASE-ZR4 modules are ideal for long-distance point-to-point connections across metro or regional networks. A common deployment scenario is within data center interconnect (DCI) applications, where two data centers located tens of kilometers apart need to exchange massive amounts of data reliably. Another use case includes telecom backhaul and midhaul applications in 5G networks, where long-reach 100G links connect core routers and baseband units. ZR4 also fits well into campus network backbones or disaster recovery site connections, where fiber infrastructure exists but the distance exceeds the reach of LR4 modules.
Advantages Over Other 100G Transceivers
Compared to other 100G modules such as 100GBASE-LR4 and ER4, the ZR4 stands out due to its extended reach of up to 80 km, making it a more cost-effective option for long-haul links that do not justify the expense or complexity of coherent optics. While LR4 is limited to 10 km and ER4 reaches about 30–40 km, ZR4 fills a critical gap for medium to long-range transmission. Additionally, ZR4 still maintains the compact QSFP28 form factor, enabling high port densities and lower system power budgets compared to larger CFP or CFP2-based coherent solutions.
Considerations for Deployment
Despite its advantages, deploying 100GBASE-ZR4 requires careful planning. The optical link budget—determined by factors like fiber attenuation, connector losses, and dispersion—must fall within the module’s specifications. While most ZR4 modules support Forward Error Correction (FEC) on the host side to enhance signal integrity, ensuring host-device FEC compatibility is crucial. Fiber cleanliness and quality also play a role, especially over such long distances. Additionally, it's important to verify whether the receiving switch or router supports ZR4 modules, even if physically compatible, to avoid interoperability issues. The 100GBASE-ZR4 delivers a strong case for environments that need long reach without stepping into the world of expensive, power-hungry coherent transceivers. It fills a crucial gap in the 100G ecosystem and continues to gain traction as the demand for longer, more efficient fiber links grows.