User Guide for FS MTP®/MPO Type-B Fiber Cables

Updated on Dec 15, 2021


MTP/MPO Cable Assemblies

MTP®/MPO fiber cables have multi-core connectors that provide more consistent and reliable performance when used in high-density, low-loss cabling, thus becoming an integral part of 40G/100G data transmission in large data centers. Hence, TIA standards define three types of MTP®/MPO fiber polarity: Type A, Type B, and Type C. MTP®/MPO cables with different types of fiber polarity may have different cabling applications. In this tutorial, we will mainly introduce MTP®/MPO type-B fiber cables and their applications. For a complete polarity guide of FS MTP®/MPO cables, you can refer to the white paper Understanding Fiber Polarity.


Table of Contents

MTP®/MPO Type-B Fiber Cable Overview

MTP®/MPO Type-B Fiber Cable Categories

MTP®/MPO Type-B Fiber Cable Applications


MTP®/MPO Type-B Fiber Cable Overview

MTP®/MPO type-B cable meaning is to use a key-up connector on both ends of the cable. Often referred to as a 40G MTP® cable, the type-B MTP® cable is extremely versatile. This cable assembly can be used to plug directly between your 40G QSFP+ optic transceivers. As you can see in the diagram, type-B cable has a "flipped" polarity and will result in a Pin 1 to Pin 12 relationship. This is extremely practical because 40G optics utilize parallel optics, meaning instead of alternating Tx and Rx in a duplex pattern, the port will look like the following diagram.

mtp type-b cable Figure 1: Type-B polarity MTP® cable


MTP®/MPO Type-B Fiber Cable Categories

Based on its different functions, MTP®/MPO type-B fiber optic cable can be divided into two main categories: MTP®/MPO trunk cables and MTP®/MPO-LC breakout cables. Depending on the nature of the connector, MTP®/MPO trunk cables are further divided into female-female, female-male, and male-male. When connecting two 40G SR4 QSFP+ transceivers in parallel optics, only female-female type B MTP®/MPO cables should be used. For MTP®/MPO-LC breakout cables, female MTP®/MPO-LC breakout cables and male MTP®/MPO-LC breakout cables are available.

NoteFrom the perspective of gender, MTP®/MPO connectors can be divided into female connector and male connector. Female connector does not have guide pins, while male connector has two guide pins. The connections between the fiber connectors are precisely aligned with the pin, and the two MTP® connectors connected to each other must be male and female. For more information about MTP®/MPO connector,  please  read the tutorial "A Comprehensive Guide to MTP® Connector".


Category Fiber Mode Gender Fiber Count Polish Type 40G Ethernet Distance 100G Ethernet Distance Wavelength
Type-B MTP®/MPO Trunk Cables OS2,OM4,OM5 Female-Female,Male-Male 12-Fibers,8-Fibers UPC to UPC 150m at 850nm,440m at 850nm 150m at 850nm 850/1300nm,1310/1550nm
Type-B MTP®/MPO-LC Cables OM4,OS2 SMF Female-4 LC,16 APC(Female)-8 LC UPC 8-Fibers LC UPC 150m at 850nm 400m at 850nm 850/1300nm,1310/1550nm

mtp type-b cable Figure 2: Type-B polarity MTP® cable types


MTP®/MPO Type-B Fiber Cable Applications

Due to the special construction of MTP®/MPO type-B cable, a female connector MTP®/MPO fiber optic cable is usually needed to match the male connector MTP®/MPO cable. The male guide pin fits into the female bore to ensure precise fiber alignment. Attempting to mate two female or male connectors can result in light loss or damage to the fiber splice. The following examples focus on the application of female MTP® type-B fiber cables.

40G-40G Direct Connection: Female to Female MTP®/MPO Type-B Polarity Trunk Cable

Except for the parallel 40G optical transmission mentioned above, female to female type-B trunk cable can also be used directly for switch to switch connectivity with no fiber patch panels. The following figure shows two Cisco 40G switches connected by a 12-fiber MTP® female cable directly.

mtp type-b trunk cable Figure 3: Female to female 12-fiber type-B MTP cable in 40G connection

Products Gender Max Data Rate Cable Type Connector 40/100G Ethernet Distance Fiber Mode
Cisco QSFP-40G-SR4 Compatible QSFP+ 850nm 150m DOM Transceiver Module / 42Gbps (4×10.5Gbps) MMF MTP/MPO-12 Male / /
MTP®/MPO Type-B Cable Female to Female / / US Conec MTP® Female 150m at 850nm OM4 50/125μm

With an MTP® adapter, a type-B fiber polarity MTP® trunk cable can be used for connecting a fiber patch panel and a QSFP+ SR4 transceiver.

40G-4x10G Direct Connection: Female MTP® to LC Type-B Polarity MTP® Breakout Cables

How to establish a connection between a 40G switch and a 10G switch? The issue can be easily resolved byemploying a female MTP®-4xLC type-B breakout cable. The following figure shows that four 10GBASE-SR transceivers interconnect with one 40GBASE-SR4 transceiver with one female MTP®-4xLC breakout cable directly.

type-b mtp-lc harness cable Figure 4: 8-fiber type-B MTP®-LC breakout cable in 40G connection

Products Wavelength Max Data Rate Cable Type Connector Fiber Mode
Cisco QSFP-40GMTP®/MPO MMF Optical Transceiver 850nm 42Gbps (4×10.5Gbps) MMF MTP/MPO-12 Male /
Cisco SFP-10G-SR SFP+MMF Transceiver 850nm 10.3125Gbps VCSEL LC Duplex /
Female to 4 LC UPC Duplex 8 Fibers Type B Plenum Breakout Cable 1310/1550nm / / LC UPC Duplex OS2 SMF 9/125μm

40G-40G Interconnections: Type-B MTP® Trunk Cables and Type-B MTP® Breakout Cables

Type-B MTP® trunk cable and breakout cable can be used together to achieve high performance fiber networking. Figure 5 shows the interconnection of 10GBASE-LR SFP+ transceivers, which are connected by a type-B MTP® trunk cable and two type-B MTP® breakout cables. It is an ideal solution for connecting two 40G Cisco switches in a data center by completing the direct connection of MTP® fiber optic cables through MTP®/MPO fiber optic panelsbecause the solution has been playing a significant role in simplifying cabling and performing high-speed fiber optic transmission.

mtp type-b trunk cable and harness cableFigure 5: type-B MTP® trunk cable and breakout cable in 10G interconnection

Products Wavelength Max Data Rate Cable Type Connector Fiber Mode
Female to 4xLC UPC Duplex 8 Fibers Type B Plenum Breakout Cable 1310/1550nm / / LC UPC Duplex OS2 SMF 9/125μm
Male to Male OM4 Multimode Elite Trunk Cable 850/1300nm / / US Conec MTP® PRO Male OM4 50/125μm


MTP®/MPO Type-B fiber cable has facilitated high-speed data transmission with its unique multi-core interface. You can choose the right cable interface and proper connection method according to your different fiber cable application needs. FS.com offers MTP®/MPO-8 and MTP®/MPO-12 Type-B fiber cables  in 10/40G direct connection and interconnection, which has made great contribution to fiber utilization improvement, cabling simplification and efficient migration to 40/100G or higher speed optical transmission in data center application.


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