Unlocking High-Speed Connectivity with 400G DR4 Transceiver
Apr 15, 20251 min read
As AI workloads and cloud services explode, data centers demand 400G networks that combine long reach, ultra-low latency, and multi-protocol agility. Enter the 400G DR4 transceiver—a game-changer with 500m SMF reach and seamless compatibility. This article dives deep into the 400G DR4 transceiver’s technology advantages, connectivity scenarios, and how to choose the right form factor module for your network needs.
What Is a 400G DR4 Transceiver?
The 400G DR4 (Reach 4-channel) transceiver is an optical module meticulously engineered for high-speed data transmission, achieving rates up to 400Gbps. DR4 refers to 500m each using OS2 single-mode fiber, and “4” implies there are 4 optical channels. Each optical channel operates at 100Gb/s. The DR4 modules use the widely deployed MPO-12 APC SMF connector to connect to 4 fiber pairs. Although an MPO-12 cable can have up to 12 fibers, only 8 out of the 12 fibers are used for the 400G DR4 transceivers (4 for Tx and 4 for Rx). An image and drawing of an MPO-12 connector are shown below:
Maximizing Reach with 500m SMF 400G DR4 Transceiver
Optimizing Performance with PAM4
The 400G DR4 adopts PAM4 modulation technology, and it utilizes internal chips to convert 4 lanes of 100G electrical signals into 4 lanes of 100G optical signals. The PAM4 modulation scheme effectively doubles the data rate by encoding two bits per symbol, thereby enhancing bandwidth efficiency and maximizing the module's performance. Such capabilities make the 400G DR4 transceiver indispensable for applications requiring low latency and high bandwidth, including cloud computing, artificial intelligence, big data analytics, and telecommunications. The internal transmission diagram of the 400G DR4 module is shown below.
Utilizing the 1310nm Wavelength
The 1310nm wavelength plays a pivotal role in optical communications, particularly for short-to-medium-range data transmission. Its prominence stems from superior characteristics such as reduced signal distortion (chromatic dispersion) and lower power loss (attenuation) compared to alternatives like the 1550nm wavelength. Optimized for distances up to 500 meters, this wavelength is ideal for applications ranging from metropolitan area networks (MAN) to medium-range, high-density connectivity needs, balancing performance and cost, and meeting modern data demands effectively.
FS's 400G InfiniBand DR4 Modules
FS offers 400G InfiniBand DR4 modules in two distinct form factors to cater to diverse networking requirements. Both undergo rigorous testing, including spectrum analysis, eye diagram tests, Bit Error Rate (BER) tests, and temperature tests, ensuring reliability across various operating conditions and environments. These tests confirm that the modules meet industry standards for performance and durability.
Specification |
Connector | MPO-12/APC | |
Wavelength | 1310nm | |
Max Power Consumption | 10W | |
Modulation (Electrical) | 4x100G-PAM4 | |
Modulation (Optical) | 4x100G-PAM4 | |
Receiver Type | PIN | |
Transmitter Type | DFB | EML |
Chip | Broadcom 7nm DSP | Macom |
Technology | InfiniBand & Ethernet | InfiniBand & Ethernet |
Inbuilt FEC | Yes | No |
Application | Flat-top OSFP for ConnectX-7 Adapter 800G-to-Two 400G Links for Switch-to-Adapter | QSFP112 for NVIDIA ConnectX-7 Adapters and BlueField-3 DPUs 800G-to-Two 400G Links for Switch-to-Adapter 800G-to-four 200G Links |
400G InfiniBand DR4 Modules Connectivity Scenarios
800G to 2x 400G Links to ConnectX-7 and/or BlueFieId-3 DPUs
The OSFP-DR4-400G-FL and OSFP112-DR4-400G modules enable seamless connectivity between 800G switches and combinations of 400G ConnectX-7 or BlueField-3 DPUs. By utilizing two MPO-12/APC OS2 fiber cables, these modules establish high-performance links to the OSFP-DR8-800G, streamlining the transition from 400G to 800G networks.
800G to 4x 200G Links to ConnectX-7 and/or BlueField-3 DPUs
The QSFP112-DR4-400G module supports downshifting to 200G speeds, enabling flexible connectivity between the OSFP-DR8-800G module and up to four ConnectX-7 adapters (and/or DPUs) via two 1:2 fiber splitter cables. This configuration optimizes resource usage and offers a scalable solution for upgrading your network infrastructure.
Selecting the Appropriate 400G DR4 InfiniBand Module
When choosing between the OSFP DR4 and QSFP112 DR4 modules, consider the following factors:
Compatibility and Device port
Whether in OSFP or QSFP112 form factors, the FS 400G DR4 InfiniBand module has been tested by the original to ensure 100% compatibility with NVIDIA ConnectX-7 adapters. When purchasing, it is important to check the port type of your devices. OSFP port and QSFP112 port are two physically distinct form factors. If you have an OSFP system, then OSFP optics and cables must be used.
Application Scenarios
On the one hand, unlike the OSFP finned-top module that connects to switches, the 400G OSFP DR4 flat-top module can only connect to ConnectX-7 network adapters. However, since the latest high-speed 800G NDR and 1.6T XDR switches use the OSFP form factor, choosing OSFP modules may facilitate future network upgrades.
On the other hand, the QSFP112 DR4 module can connect not only to ConnectX-7 adapters but also to BlueField-3 DPUs. Additionally, it supports downshifting to 200G, enabling a smooth transition from 200G network to 800G NDR network. The choice between these modules depends on specific network upgrade requirements and application scenarios.
Economic Considerations
Evaluate the cost-effectiveness of each module in relation to your specific networking needs and budget constraints.
Conclusion
The 400G DR4 InfiniBand transceiver serves as a cornerstone in advancing data center and high-speed network infrastructures. By understanding its functionalities and selecting the appropriate module form factor, organizations can achieve optimal performance, scalability, and efficiency in their networking environments. FS is committed to delivering rigorously tested, high-quality optical modules, ensuring that your network infrastructure remains robust and future-proof. Regardless of your application needs, FS can provide customized solutions to help you upgrade your network and enhance performance.