How to Choose Between MTP®/MPO Jumpers, Harnesses, and Trunks

In high-density data centers, cloud computing rooms, and AI network architectures, MTP/MPO multi-fiber optic assemblies have become the fundamental connection method for 40G, 100G, 400G, and even 800G networks. In actual cabling, the three most common types of optical cables are Jumpers, Harnesses, and Trunks. Although they have similar structures, their roles are completely different. Simply put: Jumpers handle short-distance connections, Harnesses handle interface conversion, and Trunks handle long-distance backbone transmission. Understanding these roles will allow you to quickly make the right selection.

What are MPO/MTP®?

Before understanding MTP®/MPO Jumpers, Harnesses, and Trunks, it’s necessary to understand the basic concepts of MPO and MTP®. MPO (Multi-fiber Push On) is the standard interface form for multi-fiber optic connectors, defining the connector’s structure, size, and mating method, and is the foundation of all multi-fiber optical cables. MTP® is an MPO connector brand launched by US Conec. Based on the MPO standard, it optimizes mechanical structure, insertion loss performance, and durability, while being fully compatible with MPO and allowing direct interlocking. Therefore, MTP® is often the preferred solution in high-performance data centers. For information on how to distinguish between MPO and MTP® fiber optic patch cables, please refer to the article: How to Distinguish Between MTP and MPO Fiber Patch Cable?

MTP/MPO Jumper, Harness, Trunk Selection: Based on Distance, Function, and Cabling Level

● Short-distance direct connection (typically 1–30 meters) → Choose Jumper

MTP®/MPO Jumpers, also known as straight-through patch cables, have MTP/MPO connectors at both ends and are mainly used for short-link connections between equipment and patch panels, and between equipment. They are suitable for high-speed direct connections within a server rack or between adjacent racks.

● Interface or Rate Conversion → Choose Harness

MTP®/MPO Harness, also known as break-out cable, is a conversion cable where one end is MTP/MPO and the other end is split into multiple single-, dual-, or multi-core fiber optic connectors (such as LC, SC, MPO, MMC, etc.). Its core function is to split high-speed multi-core backbone signals for traditional low-speed equipment, or to aggregate low-speed signals to a high-speed backbone, resolving interface or rate mismatch issues between new and old equipment. For example, 40G and 100G can be split into four 10G or 25G low-speed links to connect terminal equipment, facilitating mixed-rate cabling.

● Long-Distance Backbone Transmission (typically 30–100 meters) → Choose Trunk

MTP®/MPO Trunk is a high-density backbone cable with MTP/MPO or LC connectors at both ends. It features a high core count (commonly 48/72/96/144 cores), long distances, and a double-sheathed design for strong tensile strength. It is used for high-speed backbone connections between rack rows or server room areas, ensuring large-scale signal aggregation and stable transmission, and is the foundation of data center backbone cabling.

By rationally combining Jumper, Harness, and Trunk components in the cabling architecture, a data center fiber optic cabling system with clear hierarchy, strong scalability, and easy operation and maintenance can be constructed. The access layer uses Jumpers for flexible connections, the conversion layer relies on Harnesses for rate and interface adaptation, and the backbone layer uses Trunks to handle large-scale, high-density, stable transmission, thus achieving a balance between performance and maintainability.

In actual selection, in addition to type matching, the following points should be emphasized:

● Insertion Loss: In high-speed networks (such as 400G/800G), loss control is particularly critical. Typically, high-quality MTP/MPO fiber optic components can control the insertion loss of a single connector to a low level (e.g., ≤0.35 dB) to ensure link stability.

● Flame Retardant Rating: The outer sheath material of the fiber optic patch cord is related to the safety and compliance of the server room. LSZH (Low Smoke Zero Halogen) fire-resistant sheaths are typically preferred to reduce the release of toxic gases and decrease smoke density in the event of a fire, meeting the fire protection requirements of data centers and communication equipment rooms.

● Fiber Optic Patch Cord Testing: High-quality MTP/MPO fiber optic patch cords undergo systematic testing, including end-face inspection (such as 3D testing), loss testing, and environmental reliability verification, to ensure stability and consistency during long-term operation.