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

Network designers often face the challenge of reducing cable congestion in limited spaces when designing fiber systems for data centers and large enterprise equipment rooms. Network designers turn to multi-fiber MTP®/MPO cabling to overcome this challenge. However, ensuring accurate polarity across the system becomes increasingly intricate with higher data rates.

To tackle this challenge, the TIA-568 defines three types of MTP®/MPO cable polarity, namely Type A, B, and C, for configuring system polarity in multi-fiber arrays. For a complete guide of FS MTP®/MPO cable polarity, you can refer to the white paper Understanding Fiber Polarity. In this tutorial, we will mainly introduce MTP®/MPO type-B fiber cables and their applications.

MTP®/MPO Type-B Fiber Cable Overview

MTP®/MPO type-B cable uses key up connector on both ends. The type-B MTP® cable, commonly known as a 40G MTP® cable, because 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 results in a Pin 1 to Pin 12 relationship. The port will be similar to the given diagram rather than changing RX and TX into a duplex standard. This method ensures correct fiber alignment for transmitting and receiving signals in duplex (two-way) communication systems.

                                                                             Figure 1: Type-B polarity MTP® cable

MTP®/MPO Type-B Fiber Cable Categories

FS offers four types of type-B polarity fiber cables: Type-B MTP®/MPO Jumpers, Type-B MTP®/MPO Trunk Cables, Type-B MTP®/MPO-LC Cables, and Type-B MTP®/MPO Conversions.

Based on its different functions, there are 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.

Note: From 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".

                                                                           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.

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

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.

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

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 panels, because the solution has been playing a significant role in simplifying cabling and performing high-speed fiber optic transmission.

                                               Figure 5: type-B MTP® trunk cable and breakout cable in 10G interconnection

Superior Connectivity with FS

MTP®/MPO Type-B fiber cable has facilitated high-speed data transmission with its unique multi-core interface. You can choose the right cable and proper connection method according to your different application needs. Ready to redefine your network experience? FS.com offers MTP®/MPO-8/12/16/24/32/36/48/72 Type-B fiber cables in 10/40G direct connection and interconnection, which has made great contribution to fiber utilization improvement. Take action now - register for more information and transform your network with FS today.

Related Article: Understanding Universal Polarity in MTP® Cabling System