With the upgrading of data center bandwidth, large-scale deployment of 400G and commercial deployment of 800G have become mainstream. 400G/800G optical modules adopt a parallel multi-channel transmission architecture and rely on MPO high-density patch cords to achieve multi-optical path integrated transceiver, which is the core interconnection method for current high-speed networking. The number of cores, polarity, end face type, fiber specifications and construction process of MPO patch cords directly determine the connectivity, loss and operational stability of high-speed links.

Ⅰ.Core Fundamentals: Key Parameters of MPO Patch Cords in High-Speed Networking

1.MPO Patch Cord Fiber Count Specifications

High-speed networking uses only three types of MPO patch cords: 12-core, 16-core, and 24-core. The 12-core is adapted to the 4-channel 400G SR4/DR4 module, and only 8 cores are used to complete the transmission and reception. The 16-core is adapted to 8-channel devices. The 24-core is currently used in fewer scenarios.

2.Polarity Type (Interconnect Core)

To ensure one-to-one correspondence between transmitting and receiving channels and normal optical transmission of links, the 400G/800G links across the entire network mostly use Type B polarity. Type A and Type C polarities are generally used in special situations. Care should be taken to distinguish between them during the selection process to avoid faults such as channel crossover, no light, and link failure.

3.End Face and Fiber Types

The APC/UPC endface types must not be mixed: Traditional NRZ signals use the UPC endface, while PAM4 scenarios use the APC endface, which can effectively reduce return loss. Fiber optic specifications should be matched as needed: OM4/OM5 multimode fiber is suitable for short-distance SR networks within 100 meters, and OS2 single-mode fiber is suitable for medium-distance DR networks within 500 meters.

4.Male-Female Connector Mating Rules

Industry-standard compatibility: All high-speed optical module ports are male. During installation, female MPO jumpers must be used for connection. Incorrect male-to-male or female-to-female connections are prohibited to avoid connection failure or port damage.

II.Interconnection Solutions for 400G/800G Optical Modules and MPO Patch Cords

III.Summary

Currently, 400G networking has achieved large-scale commercial use, and 800G technology continues to be implemented and iterated, becoming the mainstream direction for the construction and upgrading of data centers. During the network upgrade transition period, there are technical problems such as weak compatibility of heterogeneous equipment, cross-rate link anomalies, excessive transmission loss, and cumbersome cabling and maintenance. MPO parallel interconnect technology has the advantages of high integration, high adaptability, easy operation and maintenance, and low cost, which can effectively solve various networking problems and is a high-quality technical solution for the construction of high-speed data centers.

ETU-Link Technology Co., Ltd. can meet the aforementioned needs for high-speed network construction and iterative upgrades. Their products focus on 400G/800G high-speed data center interconnect scenarios, providing QSFP-DD and OSFP high-speed optical modules and a full range of MPO cabling products to build standardized, integrated high-speed networking solutions. For product selection, technology adaptation, and customized networking solutions, please feel free to contact us!