MPO and MTP® Cable Attributes

Understanding all aspects of implementation

Today, the utilization of MPO/MTP® cables plays a crucial role in facilitating high-speed data transfers by enabling the efficient inter and intra connections between Data Storage and Distribution Points. As the demand for larger data transfer escalates due to the rapid proliferation of cloud computing, IoT, and AI applications, the prevalence of network infrastructures employing MPO/MTP® cables is set to grow significantly in the upcoming years. In order to achieve optimal results when installing and using these cables in a network environment, it is essential to possess fundamental knowledge about cable attributes and specifications. This article aims to equip readers with the necessary know-how to accurately identify the appropriate application and location for a specific cable.

MTP® / MPO Cable Attribute Guide

Cable Attributes

Guide Menu

Connector Type: MPO vs MTP®

The standard and the improved

The differentiating factor between MPO and MTP®  fiber optic cables resides in their connectors. With its advanced design, MTP® connectors offer superior mechanical characteristics and optical performance compared to MPO cables. These distinguishing features break down as follows:

MPO stands for ‘Multi-fiber Push On.’ MPO connectors are the generic model upon which MTP connectors are based. Here are the defining features and benefits of MPO cables:

  • Standard Connector
    MPO is a widely recognized industry standard. It can be used with any devices or applications that support MPO technology including QSFP+ 40GB & QSFP28 100GB transceivers.
  • Multifiber Solution
    MPO connectors can support multiple fibers in a single connector, making them a space-efficient solution for high-density applications.
  • Reduced Cost
    Due to wide range of manufacturers supplying these connectors, pricing is more competitive.

MTP® is a brand name for the MPO connector developed and manufactured by US Conec Ltd. Here are the key differentiators and benefits of MTP cables:

  • Enhanced Performance
    MTP® connectors are known for their high-performance attributes. They offer better mechanical and optical performance than the standard MPO connectors.
  • Floating Ferrule
    MTP® connectors incorporate a floating ferrule, which allows two mated ferrules to maintain physical contact while under load.
  • Removable Housing
    MTP® connectors have easily removable housings, which means the connectors can be reworked and reused, increasing their lifecycle and reducing costs over time.
  • Elliptical Guide Pins
    MTP® connectors utilize elliptical-shaped guide pins, leading to improved guidance precision and minimizing the risk of damage.

Read our full breakdown of the differences between MPO and MTP® connectors here:

Full Article Link

Read our full breakdown of the differences between MPO and MTP® connectors here:

Full Article Link

Connector Gender

Male or Female

When working with MTP®/MPO connectors, “gender” is a term used to differentiate between connectors. This helps to navigate cables and ensure the correct connector is used for a task. A firm connection is vital in aligning fiber endpoints, achieved by having guide pins on one side and receptors on the other. By being aware of these details, potential issues can be avoided and systems run smoothly.

Male Connector

WITH Guide Pins

Female Connector

WITHOUT Guide Pins

Connector Alignment

Key Positions

The key position on the connector is a mechanic feature that guarantees the correct orientation of the connector as when plugging into a receptor. A connector can be either KEY UP or KEY DOWN and the position of the key plays two important roles:

  1. Correct orientation when inserting the cable connector into a socket
  2. Ability to reference the exact fiber/strand that has to be inspected or spliced

When specifying a fiber in a connection, it is important to indicate the position of the key. The numbering of each strand corresponds to its connection in the connector. It is standard practice to assign sequential numbers to strands starting from the left to right side of the key. To illustrate this numbering system, examples are shown in the images below for an MPO-12 with key-up and key-down configurations.

Cable Polarity

Method A, B, & C

An optical link needs a pair of optical fibers to transmit signals. The optical module comprises a transmitting end (Tx) and a receiving end (Rx). Proper interconnection between the two ends is needed, which is called polarity. Polarity indicates the direction of optical signal movement in the fiber, and it is essential for matched transmitting and receiving ends. TIA 568 standard defines three methods for correct polarity, referred to as Method A, Method B, and Method C. Three types of MTP fibers, namely Type A, Type B, and Type C, are used to match the three different connectivity methods in compliance with these guidelines.

12 Fiber

24 Fiber

Cable Jacket

Color Guided Cable Ratings

MTP® and MPO cable jackets are color coded so that you can easily differentiate between them. The color corresponds with an industry standard rating for specifications of the fiber utilized in the cable. For example, the yellow jacket means the cable has a single-mode fiber and the Aqua Jacket means it has a multimode fiber. The color table below is a quick reference guide showing which cable category belongs to each color to make things easier.

Optical Fiber Category Jacket Color
Single Mode
OS1 / OS2
Yellow
Multi Mode
OM3 / OM4
Aqua
OM5
Lime Green

Cable Application

Trunk & Breakout Cable Connections

Trunk Cables

Trunk cables offer superior transmission performance and high density with minimal signal loss. These cables enable 1:1 connections where both endpoints have matching speeds, ensuring that data input on one end matches that on the other end.

The chart provided below details the correlation between transceiver transmission and receiving lane count with the required fiber count of the cable. Short abbreviations denoting Short Range (SR) and Long Range (LR) transceivers have been utilized. Following either SR or LR, a numerical value has been included representing the number of transmission (Tx) lanes and receiving (Rx) lanes respectively.

Optical Fiber Transceiver Tx Lanes Fiber Count Typical Data Rate
Multi Mode
SR4
12
40G, 100G
SR8
16
200G, 400G
CFP/CFP2/CPAK SR10
CXP SR12
24
100G
SR16
32
800G
Single Mode
(PSM4)
LR4
8
40G, 100G
LR8
16
200G, 400G, 800G

MPO-12

MPO-16

MPO-24

Breakout Cables

MPO Break-out cables are a highly effective way to split and combine data flow. One of the most common types of break-out cables is the MPO to 4 LC. Additionally, the 1 to 4 conversion is ideal for converting from 40G to 4x10G and from 100G to 4x25G, as both use the same MPO breakout cable. However, it is important to note that not all 40G and 100G transceivers can handle this conversion, as it requires a built-in MPO connector and is only available in the SR4 and PSM4 transceiver versions, which are both short-range 4-lane interfaces.

The trend of using 1 to 8 break-out conversion is gaining popularity. This involves the use of a 200G SR8 or 400G SR8 at one end and a 25G SFP28 or 50G PAM SFP56 at the other end, to match the data rate. This method simplifies the topology and reduces the number of equipment required for conversion from high to low data rate.

MPO-8

MPO-12

MPO-24

Fiber Core Assembly

Loose Tube vs Tight Buffer

There are two major forms of fiber optic cables: Loose Tube and Tight Buffered cable. While both cables have a dielectric central member and strength member, they are designed for different surroundings. Understanding the differences between the two types of cables is essential in identifying the appropriate choice for your specific needs.

Loose Tube Cable

A loose tube cable comprises 250μm fiber core and is bundled within a semi-rigid protective tube or sleeve. To protect the fibers against external forces, one to 12 fibers are insulated in individual water-blocked buffer tubes. These tubes are usually stranded around a fiberglass central strength member for more sturdiness and strength. Loose tube cables can support up to 432 fibers within the tubes and are made either in dry-block or gel-filled constructions.

Application

Loose tube cable is versatile. It offers an optional water-resistant gel surrounding the fibers making the cable ideal for harsh, high-humidity environments where water or condensation can be a problem. The gel-filled tubes can expand and contract with temperature changes, too. Loose Tube cables can be used for outdoor installation and various applications such as LAN, MAN, WAN, telecommunications, data center, and ethernet.

Tight Buffer Cable

Tight buffered cable design ensures excellent protection against environmental and mechanical damage using a 900μm buffered fiber surrounded by a water-resistant, dielectric strength member. The fiber is then covered by a flame-retardant outer jacket, which is either flexible or rugged polyurethane. Tight-buffered fiber cables can have fiber counts ranging from 1 to 144, but usually, cables with 2, 6, 12, or 24 fibers are most commonly used. For specific applications, fiber counts of 48, 96, and 144 are also available.

Application

Tight buffered cable durability and reliability make it an ideal choice for use in intra-building data centers, backbones, patch cords, equipment cables, LAN, WAN, Storage area network (SAN), and long indoor runs. Additionally, tight buffered cable is easier to install than the loose tube cable because there is no gel to clean up and it does not require a fan-out kit for splicing or termination.