100GBASE-LR4/ER4 and OTU4 QSFP28 Dual-Rate Transceivers

Updated on Nov 21, 2019 by

With the accelerated development of the Internet, cloud computing, big data and other bandwidth-intensive applications, 100G devices are more common in fast-growing cloud services and data centers and the demand for 100G optics increases accordingly. FS rolls out 100/112G OTU4 QSFP28 dual-rate transceivers to address both Ethernet and OTN issues. In this post, we will introduce FS 100G dual-rate optical transceivers: 100GBASE-LR4 and OTU4 QSFP optical transceivers and 100GBASE-ER4 and OTU4 QSFP optical transceivers.

What Is FS 100GBASE LR4/ER4 and OTU4 QSFP28 Dual-Rate Transceiver?

A dual-rate transceiver means that an optical transceiver can support two different data rates. The newly released FS 100/112G dual-rate transceiver supports both 100G Ethernet (25G per channel) and 112G OTU4 (28G per channel). Compliant with the QSFP28 MSA, IEEE 802.3ba 100GBASE-LR4/ER4, and OTU4 4I1-9D1F requirements, this kind of module is a pluggable optical transceiver with a duplex LC connector interface for long-reach data communication and interconnect applications.

100G dual-rate .jpg

There are two types of 100G QSFP28 dual-rate transceivers in terms of transmission distance. One is 100GBASE-LR4 and 112GBASE-OTU4 QSFP28 dual-rate transceiver covering 10km, 20km, and 25km communication. The other is 100GBASE-ER4 and 112GBASE-OTU4 QSFP28 dual-rate transceiver designed for 30km and 40km long-range communication. The maximum rate is set as either 103.1Gbps or 112Gbps when shipping and cannot be modified later. These transceivers, shown in the table below, are specially designed to support high-performance data communications and telecommunications equipment for demanding applications, such as switch and router interlinks and data center aggregation.

ID Transceiver
Lane Wavelength DDM
Maximum Power
73870 100GBASE-LR4 and 112GBASE-OTU4 QSFP28

L0: 1295.56nm


L1: 1300.05nm


L2: 1304.58nm (1303.54-1305.63nm),

L3: 1309.14nm (1308.09-1310.09nm)

Yes 3.5W 10km
84020 Yes 3.5W 20km
92756 Yes 3.5W 25km
88471 100GBASE-ER4 and 112GBASE-OTU4 QSFP28 Yes 4.5W 30km
88472 Yes 4.5W 40km

Working Mechanism of FS 100/112G QSFP28 Dual-Rate Transceiver Module

FS dual-rate 100G transceiver module takes the form of the four-lane Quad Small Form-factor Pluggable 28 (QSFP28). This new module converts 4 input channels of 25Gb/s electrical data to 4 channels of LAN WDM optical signals and then multiplexes them into a single channel for 100Gb/s optical transmission. Reversely on the receiver side, the module de-multiplexes a 100Gb/s optical input into 4 channels of LAN WDM optical signals and then converts them to 4 output channels of electrical data.

Figure 1. Transceiver Block Diagram


How to Make Use of FS 100GBASE LR4/ER4 and OTU4 QSFP28 Dual-Rate Transceiver?

FS 100GBASE LR4/ER4 dual-rate transceiver module offers 4 independent transmit and receive channels, each capable of up to 28Gbps operation, for an aggregate bandwidth of 112Gbps. Designed for 100G Ethernet and OTN applications, the module has a single LC port which connects to an industry-standard LC duplex single mode fiber optic cable.


100G LR4 dual-rate optical transceivers are recommended for 100GBASE-LR4 Ethernet Links and OTN OTU4 4I1-9D1F. QSFP-ER4-100G dual-rate transceivers are recommended for 100GBASE-ER4 Ethernet Links, Infiniband QDR and DDR interconnects and Client-side 100G Telecom connections.Unlike the 1G/10G dual-rate SFP+ which can be used in both 1 Gigabit Ethernet and 10 Gigabit Ethernet links to ease the transition from 1Gb/s to 10Gb/s systems, this dual-rate 100G transceiver cannot be interchangeably used, say, the transceiver used by SDH devices cannot be applied to Ethernet or Fibre Channel.

Note: This transceiver is shipped in ESD protective packaging. It should be removed from the packaging and handled only in an ESD-protected environment.


With the release of the 100G dual-rate transceivers: 100GBASE-LR4 and 112GBASE-OTU4 QSFP28 together with 100GBASE-ER4 and 112GBASE-OTU4 QSFP28, FS is enabling the optical technology market with a cost-effective path for upgrading to 100G links. Dual-rate 100G transceiver provided by FS can be designed to be compatible with many major brands, such as Cisco, HP, Juniper, etc. And every optical transceiver has been tested to ensure our customers receive the optics with superior quality. For more information on FS dual-rate 100G transceivers and solutions, please visit www.fs.com.

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