InfiniBand 200G QSFP56 Products Introduction

NADDOD Brandon InfiniBand Technical Support Engineer Jul 6, 2023

With the rapid development of data centers and artificial intelligence, high-speed, low-latency, and low-power data transmission has become an indispensable element in these fields. As a leading provider of high-speed data transmission solutions, NADDOD offers a variety of InfiniBand cables and transceiver products to meet the needs of different scenarios. This article will introduce the features and application environments of NADDOD InfiniBand HDR AOC cables, DAC cables, and transceivers, helping you to better understand the latest developments.

InfiniBand 200G QSFP56 AOC

The IB QSFP56 AOC cables combine fiber optic and electronic chip technology, offering advantages such as high-speed transmission, long-distance transmission, low power consumption, strong anti-interference, and flexible installation. It is widely used in data communication, data centers, high-performance computing, and other fields. NADDOD can provide two types of InfiniBand HDR AOCs: direct and breakout.

NADDOD provides two types of HDR InfiniBand AOC, such as QSFP56 to QSFP56 AOC and QSFP56 to 2X100G QSFP56 AOC, which can ensure high reliability of transmission due to the AOC cable’s low power consumption, low electromagnetic influence and strong heat dissipation.


The Q56-200G-A*H (HDR QSFP56 to QSFP56 AOC) cable is an active optical cable (AOC) based on QSFP56 VCSEL. It offers longer transmission distances compared to passive copper cables in data centers. It comes in specifications of 3m, 5m, 7m, 10m, 15m, 20m, and 30m, designed for 200Gb/s InfiniBand HDR systems. The AOCs support hot-plugging, making them easy to install and replace. They enable higher port bandwidth, density, and configurability at a lower cost, while reducing power requirements in data centers. However, due to the presence of modules on both ends, the AOCs are not suitable for inter-cabinet cabling and are generally used in interconnect scenarios with distances less than 30 meters.



The Q2Q56-200G-A*H (HDR QSFP56 to 2xQSFP56 AOC) cable is an economical and efficient 200Gb/s HDR to 2x100Gb/s HDR100 active breakout AOC based on QSFP56 VCSEL. It comes in specifications of 1m, 3m, 5m, 7m, 10m, 15m, 20m, and 30m, designed for 200Gb/s InfiniBand HDR systems. It enables interconnection between a 200G port on one side and two 100G ports on the other side, for example, connecting a switch to two servers. NADDOD provides efficient connectivity for short-distance interconnects, achieving higher port bandwidth, density, and configurability at a lower cost while reducing power requirements in data centers.


Connection Environment

The diagram below illustrates a high-bandwidth, low-latency, and highly reliable InfiniBand connection scheme. It utilizes breakout AOC cables to connect Leaf switches to GPU servers with HCA cards and storage devices. It also employs direct AOC cables to connect to the Spine Switch at the same rate.

Connection Environment

InfiniBand 200G QSFP56 DAC

NADDOD offers InfiniBand DAC cables, which are the most cost-effective way to create high-speed, low-latency 200G/HDR connections in InfiniBand switching networks. Different lengths are available to meet the distance requirements of NVIDIA GPU-accelerated AI end-to-end systems.


The Q56-200G-CU*H (HDR QSFP56 to QSFP56 DAC) is a direct attach copper cable that follows the 200Gb/s InfiniBand HDR standard. It consists of eight high-speed copper pairs, with each pair capable of transmitting data at up to 50Gb/s. The cable lengths available are 0.5m, 1m, and 1.5m.



The Q2Q56-200G-CU*H (HDR QSFP56 to 2xQSFP56 DAC) is a breakout cable that also adheres to the 200Gb/s InfiniBand HDR standard. Unlike the 200G HDR QSFP56 to QSFP56 DAC, this DAC cable connects to a 200G QSFP56 port on one end and can connect to two 100G QSFP56 ports on the other end, enabling high-speed data transmission from 200G to 100G. The cable lengths available are 1m, 1.5m, and 2m.


Shared Features

● Each QSFP56 port includes an EEPROM that provides product information readable by the host system.
● They offer efficient short-distance interconnectivity to achieve higher port bandwidth, density, and configurability.
● They have low latency, high bandwidth, low power consumption, and excellent reliability.
● They find extensive applications in data centers, artificial intelligence, and other fields, particularly in scenarios requiring high-speed data transmission.

Connectivity Environment

The diagram below illustrates the utilization of NADDOD HDR InfiniBand DAC cables for short-distance connections between ToR switches and switches/servers.

Switch to Switch Interconnection


Switch to Server Interconnection


InfiniBand HDR QSFP56 Transceiver

200G SR4 QSFP56

The Q56-200G-SR4H (200GBASE-SR4 QSFP56) optical transceiver is designed with a QSFP56 form factor and features MPO/MTP-12 APC connectors. It is specifically designed for short-distance applications in 200Gb/s InfiniBand environments. It utilizes 4 channels of 53Gb/s PAM4 850nm VCSEL transmitters and PIN receivers. Both the transmit and receive channels have built-in CDR chips, with power consumption below 5W. It can transmit distances of up to 70m over OM3 multimode fiber and up to 100m over OM4 or OM5 multimode fiber with FEC enabled.


200G FR4 QSFP56

The Q56-200G-FR4H (200GBASE-FR4 QSFP56) optical module is designed for medium to long-distance applications in 200Gb/s HDR InfiniBand using duplex LC connectors and the QSFP56 form factor. It utilizes a non-cooled EML CWDM transmitter, which multiplexes it into a single optical data stream using wavelength division multiplexing technology, and demultiplexes it into four optical data streams at the receiving end using an optical demultiplexer. It can transmit distances of up to 2km over 1310nm OS2 single-mode fiber (SMF), effectively reducing customers’ fiber cabling costs.


Application Environment of HDR InfiniBand Transceivers

The specific application of these optical modules depends on the requirements of the actual environment, considering the different features and functions of each module.
200G HDR SR4 is primarily used for interconnectivity between InfiniBand HDR devices, such as switch-to-network cards or switch-to-switch connections, with transmission distance requirements ranging from 30m to 100m, as shown in the diagram below.


200G HDR FR4 is specifically designed for network environments with transmission distances of 500 meters and 2 kilometers. It is suitable for medium to long-distance systems in InfiniBand, extending InfiniBand to remote infrastructures and edges. It allows for local and encrypted InfiniBand connections between remote data centers or data centers and remote storage infrastructures, enabling high availability.


In summary, NADDOD’s HDR InfiniBand AOC cables, DAC cables, and optical transceivers offer low latency, high bandwidth, low power consumption, and high reliability. They have been widely used in data centers, artificial intelligence, and other fields, receiving widespread praise from customers. We look forward to providing efficient, stable, and reliable data transmission solutions to more customers, supporting digital transformation and intelligent development.


Q1: Can InfiniBand cables be used on switches that are not Mellanox?

NADDOD provides InfiniBand cables that can be used on devices that are not Mellanox devices, as long as the switches are not highly compatible, such as Huasan and Huawei.

Q2: Can InfiniBand cables be used on Ethernet switches?

InfiniBand cables provided by NADDOD are compatible with both InfiniBand and Ethernet, but Ethernet cables are only compatible with Ethernet.

Q3: What is the latency and bandwidth of HDR InfiniBand cable?

The latency of the InfiniBand cable provided by NADDOD is 1.27us.

And the bandwidth of InfiniBand cable provided by NADDOD is 197Gbps.

Q4: What are the lasers used in 200G transceivers?

Lasers are mainly divided into two categories: Direct Modulation DML and External Modulation EML.

Directly modulated lasers include VCSEL, FP, DFB, all of which are single lasers. Mainly used for close range and low-power scenarios. Among them, VCSEL belongs to surface emission, FP and DFB belong to side emission.

EML laser: EML consists of two parts, the laser source CW laser, the other part is EAM modulator. Because it can solve the problems of DML linear frequency modulation, dispersion, close range transmission, so it is mainly used for high-speed or long-distance scenes.

Q5: How many modulation methods are available for 200G transceivers?

There are two modulation methods, which are PAM4 modulation and NRZ modulation. Among them, 200G QSFP56 adopts 4×50G PAM4 modulation. 200G QSFP-DD adopts 8×25G NRZ modulation.

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