What is SR,DR,FR,LR,ER for 200G QSFP56 transceiver?

With the rapid development of data centers, 100G optical modules are not enough to meet the growing network upgrade requirements and 400G is not yet popular, so 200G QSFP56 optical transceivers have become the mainstream solution for 200G Ethernet deployment in data center, AI, clouding computer, etc.

Difference between 200G QSFP56 and 40G QSFP+ and 100G QSFP28

200G QSFP56 optical module is an upgraded version of 40G QSFP+ and 100G QSFP28 transceivers, which use mainstream DSP (Digital Signal Processors) and hot-plugged QSFP56 packaging type. It has 4 independent transmit and receive optical signal channels, and the transmission rate of each channel is 50G.

Unlike QSFP28 and QSFP+ optical modules, the 200G QSFP56 optical module uses PAM4 modulation technology, which overcomes the weak capacity of traditional NRZ modulation at 56G rate, doubles the bit rate without increasing bandwidth, and significantly reduces the loss caused by the transmission channel. Compared with NRZ modulation technology, PAM4 technology does not require 8 x 25G channels to achieve 200G transmission, so it saves fiber costs while reducing link losses, and can transmit more data on existing optical fibers, making it more suitable for use in ultra-large-scale data center networks.

What do 200G QSFP56-SR4, FR4, LR4, ER4 stand for?

QSFP56 SR4, DR4, FR4, LR4, ER4 actually represent the transmission distance of the 200G QSFP56 optical modules with single mode fiber maxim 100metr, and singlemode fiber from 2km to 40km . Details as below:

200G QSFP56 SR4

200G QSFP56 SR4 is a 200G Ethernet switch direct connection solution with a 4-channel full-duplex transceiver module, MPO 12-core interface, central wavelength of 850nm, built-in CDR at the transmitter and receiver, and short-distance transmission with multi-mode fiber (MMF). The transmission distance with OM3 multi-mode fiber can reach up to 70m, and the transmission distance with OM4 or OM5 multi-mode fiber can reach up to 100m.

200G QSFP56 DR4

200G QSFP56 DR4 is a 4 channel full-duplex transceiver, which is compliance with QSFP56 MSA and IEEE 802.3bs 200GBASE-DR4 Ethernet standards. It adopts MPO12-core interface, working wavelength of 1310nm, 50G PAM4 and single-mode parallel technology, if the FEC is turned on, the transceiver can transmit signal at maximum 500meter through single mode fiber (SMF).

200G QSFP56 FR4

200G QSFP56 FR4 complies with the IEEE 802.3bs 200GBASE-FR4 specification, adopts dual LC interface, works at CWDM4 wavelength, uses uncooled EML CWDM transmitter, and can reach a transmission distance of up to 2km through dual-core single-mode fiber (SMF), which can effectively reduce customers’ fiber cabling costs.

200G QSFP56 LR4

200G QSFP56 LR4 is the most common 200G fiber optic transceivers for long-distance DCI interconnection. It adopts dual LC interface, works at LDWM4 wavelength, and can reach a transmission distance of up to 10km/20km through single-mode fiber (SMF) when FEC is turned on in the system.

200G QSFP56 ER4

In ultra-long-distance transmission, the 200GE QSFP56 ER4 optical module is usually selected. It uses a dual LC interface, an operating wavelength of LDWM4, and uses 50G PAM4 and LWDM4 technology. If FEC is turned on, it can transmit maximum 40km distance through a single-mode fiber (SMF).

Yingda can provide various optical modules as well as 200G QSFP56 AOC cable and 200G QSFP56 DAC cable. We are shipping them in large quantities in the past two years.