A Guide Based on Core Numbers to Choose The Right MTP/MPO Cable

In the context of accelerating digitalization, the rational selection of MTP/MPO fiber optic cables is of great significance in achieving efficient and stable data transmission. The network bandwidth makes the number of cores a key factor affecting transmission performance and deployment flexibility. This article focuses on the importance of core count, provides selection references for different application scenarios, and helps users make more targeted decisions when building data centers or optimizing existing network systems.

 

What is an MTP/MPO Cable?

 

MTP/MPO cables are a class of high-density multi-core fiber optic connectivity solutions widely used in data centers and telecom networks, which are designed to achieve fast connection of multi-core fiber optics through a single interface.

 

Both MPO and MTP cable types are highly similar in construction and application, using factory pre-terminated processes and standardized connectors, which greatly simplifies deployment compared to traditional field fusion cabling. The plug-and-play design not only improves cabling efficiency but also maintains stable performance and is, therefore, commonly adopted in high-density, high-speed transmission environments.

 

A Brief Overview of Common MTP/MPO Cable Types

 

MTP/MPO cables are composed of multi-core optical fibers with standardized connectors and can be divided into two main categories according to different structures and usage: trunk cables and harness cables.

 

MTP/MPO trunk Cables

 

MTP/MPO Trunk fiber optic cables are commonly used to build the main link or horizontal cabling inside the data center. They are usually equipped with MTP/MPO connectors at both ends for quick deployment and connection. The number of fibers in a trunk cable can be extended from 8 to 48, making it suitable for high-capacity and high-density transmission needs.

 

MTP/MPO Breakout/Harness Cables

 

The MTP/MPO breakout cables are used to split a multi-core MTP/MPO connector into multiple single- or dual-core connectors for direct connection to equipment ports. Common conversions include MTP to LC, MTP to SC, and so on. In addition, these cables can be equipped with a variety of core configurations, such as 8-, 12-, 16-, or 32-core, depending on the application.

 

The flexible core design enables them to be adapted to network architectures of different sizes and performance levels. As transmission technology continues to evolve, the structure of MTP/MPO fiber optic cables is constantly being updated to support higher bandwidths and more complex application environments.

 

How to Choose the Right MTP/MPO Fiber Optic Cable According to Core Numbers

 

The core count configuration of MTP/MPO cables has a direct impact on the efficiency and expandability of the network operation. Therefore, many factors should be taken into consideration when selecting the right MTP/MPO cables. This section will focus on several key considerations involved in core number selection.

 

Setting the Core Number According to Network Size and Transmission Requirements

Different network environments require significantly different fiber counts. Data center environments with high data density and bandwidth pressure usually require more fiber optic cables to meet the concurrent transmission of heavy traffic. In smaller or relatively simple network scenarios, on the other hand, configurations with fewer cores may be sufficient.

 

Ensure Compatibility with Existing Systems

When adding new cabling, the choice of core count should be consistent with the type of equipment interfaces and module standards currently in use. Confirming in advance that new fiber optic cables will be compatible with existing connectors or wiring systems can help reduce the risk of adaptation issues during deployment.

 

Allow for Future Expansion

The life cycle of a network architecture is often longer than the technology change cycle. If you are likely to add equipment or increase bandwidth in the future, it is recommended that you allow for some redundancy by choosing fiber optic cables with a core count slightly higher than your current needs, thus reducing the cost and complexity of future replacements or re-routing.

 

Finding the Balance Between Performance and Budget

While more cores mean greater scalability and higher transmission efficiency, the cost will also rise. When configuring a solution, the ROI ratio should be reasonably evaluated in relation to the project budget and actual usage frequency to avoid wasting resources due to over-configuration.

 

MTP/MPO Cabling Reference Based On The Core Numbers

 

40G MTP/MPO Cabling Methods

 

When building a 40G data center network, it's common to use 12-core MTP/MPO connectors. This architecture can handle 40Gbps transmission rates in a single fiber optic cable, making it great for environments with a lot of data and high bandwidth needs. Typical implementations divide the 12-core fiber into six channels, each supporting Ethernet transmissions of up to 10Gbps, with actual rates varying depending on distance and system configuration.

 

In a 40G link configuration, four cores of fiber are used for transmit (Tx), four cores are used for receive (Rx), and the remaining four cores are left idle.

 

40G to 4x 10G Application Scenarios

When 40G devices are connected to multiple 10G interfaces downstream, a harness structure is usually used. Take the QSFPTEK S7600-24X2Q, for example; its single 40G QSFP+ port can be divided into four independent 10G channels. Through an 8-core MTP to LC harness cable, the MTP connector is connected to the 40G port end, and the four LC connectors on the other end are connected to the 10G interfaces, realizing data shunting and aggregation between multiple ports.

 

 

40G Point-to-Point Connection

When there are 40G interfaces between two devices, the most direct connection is to use a 12-core MTP fiber optic trunk cable to connect two QSFP+ modules end-to-end. This point-to-point connection is not only suitable for building links between 40G but can also be used in some 100G system cabling scenarios, provided that the optical modules and interface specifications are consistent.

 

 

100G MTP/MPO Cabling Methods

 

The QSFP28 100G transceivers are typically connected to the fiber using the MTP/MPO-12f interface, where only eight fibers are involved in the transmission, and the remaining four are idle. In short-distance scenarios, the multimode SR4 solution is the most economical and suitable for high-speed links up to 100 meters. When the transmission distance is longer, usually turn to use 8-core single-mode fiber to achieve the PSM4 scheme to meet the needs of data transmission over longer distances.

 

In the 1-to-4 application scenario, one QSFP28 100G interface can be tapped into four SFP28 25G interfaces with the help of an MPO-LC 8-core splitter cable to realize bandwidth splitting and resource multiplexing.

 

Multimode Fiber Optic Solution: SR4 Parallel Transmission (BASE-8)

QSFP28 SR4 is typically used for short-distance connections between switches or between devices, often in the same switching area or rack. Due to the close proximity, most of these connections are point-to-point direct connections.

 

 

In addition, the SR4 interface also supports split applications from one 100G port to multiple 25G ports, such as 25G interfaces from one switch to four servers, for flexible resource allocation.

 

  

Using a standard 12-core MTP fiber optic cable can improve link redundancy by properly configuring patch panels. Even if one channel fails, the other channels can still maintain normal operation, thus improving the stability and scalability of the system.

 

Single-mode fiber solution: PSM4 parallel transmission (BASE-8)

The QSFP28 100G interface with PSM4 is suitable for point-to-point deployments over longer distances. Similar to multimode solutions, these links are mostly found in the same area or inside a rack and can be directly connected via a single 8-core single-mode fiber.

 

 

Similarly, the PSM4 supports splitting from a single 100G interface to multiple 25G interfaces, making it ideal for bandwidth allocation among multiple servers in a rack. This configuration is not only easy to manage but also provides the flexibility to adjust resources according to business load.

 

200G MTP/MPO Cabling Methods

 

Although most major vendors such as Cisco, Juniper, and Arista have skipped the 200G phase and gone straight to the 400G market, there are still some 200G QSFP-DD transceivers that have been deployed in real-world scenarios, such as the QSFP56 200G SR4 and QSFP56 200G FR4 models from QSFPTEK. 

 

200G-to-200G Direct Links

When building 200G-to-200G direct links, standard 12-core MTP (MPO) fiber cable can be used to connect two QSFP56 200G SR4 modules to achieve point-to-point high-speed interoperability.

400G MTP/MPO Cabling Method

 

MTP/MPO fiber optic cable assumes the core transmission task in a 400G network, and its multi-core structure can realize the interconnection of high bandwidth density. Currently, the main application form covers four categories, the use of jumper types including 8-core, 12-core, and 16-core three configurations.

 

Among them, 8-core or 12-core MTP/MPO single-mode cables are commonly used for the direct connection of two 400G-DR4 optical modules, which is suitable for short-distance single-mode scenarios. 16-core MTP/MPO cables have a wider range of adaptability and can be used to connect 400G-SR8 to 200G SR4 optical modules or 400G-8x50G to 400G-4x100G transceivers. In addition, the 8-core MTP to 4G transceiver can be used to convert between different transmission architectures.

 

In addition, 8-core MTP to 4-core LC duplex cables are also commonly used for connecting 400G-DR4 and 100G-DR optical modules, supporting flexible networking among multiple modules.

 

As the network moves towards an 800G rate, MTP/MPO cables are becoming more and more critical in the network structure due to their high-density layout capability, bandwidth support, and flexible access methods. Whether it is a point-to-point connection or a multi-terminal breakout application, MTP/MPO cables enable efficient coordination between 800G, 400G, and 100G modules, laying the foundation for future network expansion.

 

Direct Connect Cabling Solutions for 800G Networks

 

For the high-speed transmission needs of large-scale data centers, 16-core MTP trunk cables are specially designed for the direct connection between 800G QSFP-DD/OSFP DR8 and OSFP XDR8 optical modules. This cabling solution meets the requirements for data communications at ultra-high bandwidths and is a fundamental option for building 800G interconnects.

 

 

In real-world deployments, such as the connection of OSFP 800G DR8 modules, 12-core MTP trunk fiber optic cables are typically used for point-to-point transmission to support short-distance, high-throughput scenarios.

 

 

800G to 8x 100G Modules

For 800G to 8x 100G transceivers, 16-core MTP-LC breakout cables are ideal. These cables are suitable for applications such as 800G OSFP XDR8 to 100G QSFP28 FR and 800G QSFP-DD/OSFP DR8 to 100G QSFP28 DR, especially for breakout in high-density network architectures.

 

 

800G to 2x 400G Modules

Interconnecting 800G to two 400G modules is typically done using 16-core MTP converter cables, which saves cabling structure and controls module insertion loss and costs compared to using a converter box. This provides greater flexibility and cost-effectiveness when upgrading a network from 400G to 800G.

 

In network architectures that utilize InfiniBand technology for high-speed connectivity, 12-core MTP trunk cables can also be used to connect OSFP and QSFP112 multimode transceivers in both dual-port and single-port versions for a wide range of high-bandwidth scenarios compatible with Ethernet and InfiniBand.

 

Summary

The choice of core count for MTP/MPO cables should be judged in the context of the actual application scenario. Only by matching the number of fibers with the specific needs of the network architecture can efficient data transmission and resource allocation be achieved. Proper cabling planning not only enhances network performance but also reserves space for future expansion.

As a leading global provider of enterprise-class communication solutions, QSFPTEK offers a wide range of MTP/MPO fiber optic cable products and supports customization according to project requirements, helping to build a more flexible and scalable data center network. Choosing the right cabling solution is critical in the face of increasing bandwidth pressures. Join QSFPTEK now to get exclusive technical support and provide more reliable protection for network construction.