Category Archives: MPO Assemblies

8-Fiber MTP VS. 12-Fiber MTP Cables

MTP fiber cable in data center becomes increasingly popular in data center with the wide deployment of 40G and 100G network. It is common that 40G and 100G network usually based on 12-fiber MTP networking system. However, not all the 12 fibers of MTP cable are used.8-fiber MTP cable

12-Fiber MTP Cable During Transmission

There are usually 4 fibers left unused, if you are using a 12-fiber MTP cable to transmit 40G with QSFP+ module or 100G with QSFP28 module. The following shows how 12-fiber MTP fiber cable works when it is used to be connected with 40Gbase-SR4 QSFP+ module. If more 12-fiber MTP cables are used, more optical fibers will be wasted. As IEEE standards like 40GBASE-SR4 and 40GBASE-SR10 uses only 8 fibers for dual-way transmission, manufacturers provide new versions of MTP fiber cable which contains only 8 optical fibers but still used the standard MTP interfaces.40gbase-sr4

Base-8 MTP for Higher Density and Lower Utilization

Network built with 8-fiber MTP system can transmit the same data with less cost and higher density compared with 12-fiber MTP system. All fiber will be 100% utilized in base-8 MTP products. It could be a cost-effect solution for both 40G to 40G transmission and 40G to 10G transmission. 8-fiber MTP trunk cables and 8-fiber MTP-LC harness cable are already provided in the market. There are also rack designed 8-Fiber MTP breakout panels for 40G to 10G applications.

MTP-LC-harness-cable MTP-LC-harness-cable
MTP-LC Harness Cable MTP-LC 40/100G Breakout Panel

Convert 12-Fiber MTP to 8-Fiber MTP Cabling System

However, most MTP cabling systems are based on 12-fiber or 24-fiber MTP system, especially for backbone cabling. MTP conversion cables are provided in the market which offer conversion between 12/24-fiber MTP and 8-fiber MTP cabling systems. The following shows two types of 8-fiber MTP conversion cables which can provide 12-fiber to 8-fiber MTP conversion and 24-fiber to 8-fiber MTP conversion separately.

24 to 8 fiber MTP conversion cable 12 to 8 fiber MTP conversion cable
1*3 MTP Conversion Cable 2*3 MTP Conversion Cable

If you have already deployed 12-fiber MTP cabling system in your data center, 2*3 MTP conversion cable is suggested to be used. With one end terminated with two 12-fiber MTP cable and the other end terminated with three 8-fiber MTP connectors, 12-fiber to 8-fiber MTP cabling conversion could be achieved, as well as 100% optical fiber utilization in 12-fiber MTP system.

1*3 MTP conversion cable has a 24-fiber MTP cable on one end and three 8-fiber MTP cable on the other end. With this cable, a length of 24-fiber MTP cable can provide three ways of 40G signal dual-way transmission. All the fibers in a 24-fiber cabling system cable be used.


It is clear that the 8-fiber, 12-fiber based and 2-fiber based cabling system will exist for a long term in 40/100G network. 8-fiber MTP cabling system can provide higher optical fiber utilization with lower cost and higher cabling density. If you want to transfer 12-fiber MTP system to 8-fiber MTP system, you can use MTP conversion cables. 8-base MTP system, could be regarded as an additional option for the existing fiber network infrastructure.

MTP Conversion Cable and Its Usage

12-fiber MTP and 24-fiber MTP cables are widely used in 40G and 100G high density cabling. However, in many cases, not all the fibers are used. For instance, to connect a 40G-SR4 QSFP+ module, we usually use a 12-fiber MTP cable with only 8 fibers in use. If you have built a 24-fiber cabling system, you can use MTP conversion cable to make full use of the existing optical fibers.

MTP conversion cable

MTP Conversion Cable

Unlike MTP-LC harness cable, MTP conversion cables are terminated with MTP connectors on both ends. However, the MTP connectors on each end are different in fiber counts and types. MTP conversion cable can provide more possibilities for the existing 24-fiber cabling system. The following are the most commonly used MTP conversion cable:

1*2 MTP conversion cable 2*3 MTP conversion cable 1*3 MTP conversion cable
1*2 MTP conversion cable 2*3 MTP conversion cable 1*3 MTP conversion cable
24-Fiber MTP to 2*12-Fiber MTP 2*12-Fiber MTP to 3*8-Fiber MTP 24-Fiber MTP to 3*8-Fiber MTP
MTP Conversion Cable Application

The total fiber counts of the above three MTP conversion cables are all 24. But the can provide different connections in multi-fiber cabling system. The following will introduce the applications of these cables.

1*2 MTP Conversion Cable

This MTP conversion cable has one end terminated with a 24-fiber MTP connector and the other end terminated with two 12-fiber MTP connector. With this cable, two 12-fiber optical singles can be transferred on to a 24-fiber cable for transmission. In multimode cabling system, the optical signals of two 40G-SR4 QSFP+ modules can be transmitted over a single 24-fiber MTP cable as shown in the following picture.

1*2 MTP conversion cable
1*3 MTP Conversion Cable

1*3 MTP conversion cable has one 24-fiber MTP connector terminated on one end and three 8-fiber MTP connector one the other end. The 8-fiber MTP connectors can be connected to 40G-SR4 QSFP+ modules. This MTP conversion cable utilizes 100% of the existing 24 optical fibers. Each fiber can be used to transmit 10G optical data. Three 40G dual-way transmissions can be achieved on the existing 24-fiber MTP cable. It can also be used to breakout the 120G CXP module signals into three 40G QSFP+ SR4 optical signals.

1*3 MTP conversion cable
2*3 MTP Conversion Cable

2*3 MTP conversion cable is terminated with two 12-fiber MTP connectors and three 8-fiber MTP connectors. This MTP conversion cable allows three 40G-SR4 optical signal transmit on the existing two 12-fiber MTP trunk cables as shown in the following. If you have built a 12-fiber MTP cabling system. This 2*3 MTP conversion cable can increase about 30% capacity of the existing network.

2*3 MTP conversion cable

MTP Conversion Cable Selection

MTP conversion cables are designed to provide a more flexible multi-fiber cabling system based on MTP products. It can largely increase the capacity of the existing 12-fiber and 24-fiber MTP network. The above mentioned MTP conversion cable in different fiber types and cable lengths. Kindly contact for more details if you are interested.

12-Fiber MTP Cabling System

MTP fiber cables and related components are now widely deployed in high speed fiber optic transmission system. MTP cables really provide great performance during 40G and 100G transmission over both short and long transmission distances. But there are so many types of MTP components like MTP cables, MTP cassettes, MTP adapters, MTP patch panels, etc. And all of these products are available in different MTP polarity types. Customers can get confused easily by these MTP products.

12-fiber MTP trunk cable

In addition, unlike traditional duplex transmission on two fibers or BiDi transmission over a single fiber, MTP system transmits optical signal over 12, 24 or more fibers at the same time. More fibers and cables are employed in MTP cabling system. Thus, technicians in data center or server room are still facing a headache problem which is MTP cable management. This post is to offer the details of a commonly used MTP cabling system—12-fiber MTP cable system for better understanding, selecting and management of MTP products.

12-Fiber MTP Cabling Applications

The 12-fiber MTP cabling system is usually used in the following standards: 40GBASE-SR4, 40GBASE-PLRL4, and 40GBASE-PLR4. 40GBASE-SR4 is used for 40G transmission in short distances up to 150 meters over OM4 fibers. 40GBASE-PLRL4 and 40GBASE-PLR4 support transmission distance over single-mode fiber up to 1.4km and 10km separately. These standards use 40G parallel transceivers with 12-fiber MTP interfaces.


Except 40G transceivers with 12-fiber MTP interfaces, there is a wide range of 12-fiber MTP connectivity components for transmission. These MTP cabling products cable be used in a lot of applications.

12-Fiber MTP Cabling Connectivity Components

12-Fiber MTP Trunk Cable: MTP trunk cable can be regarded as MTP to MTP fiber patch cable. MTP trunk cable is terminated with MTP connectors on both ends. The MTP connectors can be male (with guide pin on the contact interface) or female (without guide pin). As above mentioned, MTP cables can be divided into different types: Polarity A, Polarity B and Polarity C. A previous of my article “Understanding Polarity in MPO System” has introduced the polarity of MTP components. You can follow this article about the MTP polarity details.

The most commonly used MTP trunk cable is a single strand of cable, which can provide duplex 40G transmission at the same time. There are also MTP trunk cables which are composed by several strands of cables. Take the example of 12-fiber MTP trunk cables as shown in the following picture. On the left of this picture, there is a 12-fiber MTP trunk cable which is a single strand cable. On the right of this picture, there is a 72-fiber MTP trunk cable which is composed by 6 strands of 12-fiber MTP trunk cable.

12-fiber MTP trunk cable

12-Fiber MTP Harness Cable: MTP harness cable is a length of fanout cable with one end terminated with MTP connector and the other end terminated with several connectors like LC and SC. 12-fiber MTP harness cables also come in a variety of types according to fiber type, polarity type and connector types. The following picture shows a most commonly used MTP-4 duplex LC fiber cable.

MTP-8LC harness fiber cable

12-Fiber MTP Cassette: MTP cassette is like MTP harness cable which also provides the transferring between MTP interface and LC or SC interfaces. But MTP cassette can protect the fragile optical fibers inside the metal box, and has lower space requirements than MTP harness cable. The following picture shows a 12-fiber MTP-LC Cassette.

12-FIber MTP-LC Cassette

Typical 12-Fiber MTP Cabling Guide

The 12-Fiber MTP fiber optic products can be used in many situations not only for 40G fiber network. The following introduces several typical fiber cabling solutions using 12-fiber MTP products.

12-Fiber MTP Products in 10G to 10G Transmission

The following picture shows the wire guide for 10G to 10G connections using OM3 12-fiber MTP fiber cables and 12-fiber MTP-LC cassettes. A 10G link just uses two of the 12 fibers. On each end of this link, up to six 10GBASE-SR SFP+ modules can be connected to the fiber optic network, which means up to 60G can be transmitted by the following 12-fiber MTP system.

10G MTP fiber cabling

12-Fiber MTP Products in 40G to 40G Transmission

For 40G to 40G transmission, MTP trunk cable is usually being used. The following picture shows the connection of two brocade ICX 7750 switches over long transmission distance. Brocade compatible QSFP-PLR4-40G transceivers are being used on both ends of this 40G fiber link. 12-fiber MTP OS2 trunk cable is being used to connect the QSFP+ modules on each end.

40G-QSFP-PLR4 Cabling

    Items required in this 40G to 40G fiber optic link

  • OS2 12-Fiber MTP Trunk Cable

12-Fiber MTP products in 40G to 10G Transmission

Sometime the 40G device is still required to be connected with 10G devices. Here takes the example of connection between 40G QSFP+ port on Brocade 7750 and 10G SFP+ port on Brocade Fastlron FCX6245 over long transmission distances. To distribute the 40G signals into four 10G, Brocade compatible QSFP-PLR4-40G transceiver, and Brocade compatible 10G-LR SFP+ transceiver, 12-fiber MTP-LC cassette, 12-fiber MTP trunk cable and four LC-LC duplex single-mode fiber patch cables are used. The MTP cassette transmitting the MTP interface to the LC interfaces as shown in the following picture.

40G-PLR4 cabling

    Items required in this 40G to 10G fiber optic link

  • OS2 12-Fiber MTP Trunk Cable
  • OS2 12-Fiber MTP-LC Cassette
  • OS2 LC-LC Fiber Patch Cable
  • 10G-LR SFP+

12-fiber MTP cabling system is a cost-effective and space saving solution for both 10G and 40G transmission. As most of the MTP fiber products are factory pre-terminated, these products can provide fast installation and great network performance. FS.COM provides full range of MTP fiber optic products. You can visit FS.COM or contact for more details about MTP fiber cabling.

How to Connect 40G QSFP+ SR4 Transceivers to Network

40G network is gradually being applied in today’s backbone transmission network, during which long distance transmission is required. 40G QSFP+ SR4 fiber optic transceiver is being widely applied for 40G transmission in short distances. Generally, 40G QSFP+ SR4, working on wavelength of 850 nm, can support 40G fiber optic transmission a distance up to 150 m over OM4 multimode optical fiber. Inserted in switch, QSFP+ SR4 module utilizes a MTP/MPO interface for dual way transmission. There are a lot of methods to connect QSFP+ SR4 transceivers with other devices for different applications, by using different connectivity products. In addition, the cabling for 40G is relatively more difficult than that of 10G network, which requires more cables and spaces. The following will introduce several high density QSFP+ SR4 transceiver cabling methods.

QSFP+ SR4 40G to 40G Applications

40G to 40G transmission is needed in a 40G fiber optic network. The following picture simply illustrates how 40G to 40G multimode transmission is being achieved by QSFP+ SR4 transceivers. Two QSFP+ SR4 modules are separately inserted in two 40G switches. Then the two transceiver are connected by a length of multimode MTP trunk cable. This is the simplest way to use QSFP+ SR4 transceiver.

40G cabling

In some cases, there are lot of 40G connections required at the same time and same places, which means the increasing of both cable count and cabling difficulty. For better cable management and higher density cabling, a 48-port 1U rack mount MTP fiber patch enclosure can be used as shown in the following picture. Up to four 12-port MTP fiber adapter panels can be deployed in this standard 1U rack mount enclosure. With the help of this 48-port MTP fiber enclosure, cable management for 40G connections could be easier.

40G to 40G cabling

QSFP+ SR4 40G to 10G Applications

QSFP+ SR4 is a parallel fiber optic transceiver which means it uses four fibers for transmitting and four fibers for receiving at the same time. The 40G fiber optic signal can be separated into four 10G signals to meet the 40G to 10G transferring requirements. The fiber optic cable count will be increased at the 10G distribution end. Usually a breakout MTP-8LC harness cable is used. For better cable management, a 1U 96-fiber enclosure is recommended, which includes four HD MTP cassettes transferring MTP front the 40G end to LC at the 10G end. Four 10G-SR SFP+ modules, inserted in 10G switch/ports, can be connected to the corresponding LC ports on this fiber enclosure to achieve the duplex transmission between 40G and 10G.

40G to 10G cabling

For higher cabling density, the above mentioned 48-port 1U rack mount MTP fiber patch enclosure is still being recommended, which can provide high density 40G MTP cabling environment. And additional MTP-8LC harness cables should be used for transferring signals between 40G and 10G (shown in the following picture).

40G to 10G high density cabling


Depending on its parallel transmission mode, QSFP+ SR4 modules can meet a variety of cabling applications with great flexibility. The above methods is just several commonly used ones, detailed cabling methods for QSFP+ SR4 modules are depended on the practical applications and cabling environments. Related products for the above mentioned methods are listed in the following tables. Kindly visit FS.COM or click the attached links for more details. You can also contact for more information about 40G cabling.

Products Description
40G QSFP+ SR4 Module 40GBASE-SR4 QSFP+ 850nm 150m MTP/MPO DOM Transceiver
10G-SR SFP+ Module 10GBASE-SR SFP+, 850nm 300m, MMF, LC duplex
MTP Trunk Cable 12 Fibers OM4, 12 Strands MTP Female to Female, Polarity Type B
MTP-LC Harness Cable 8 Fibers OM4, 12 Strands MTP Harness Cable, Polarity Type B
LC-LC Fiber Patch Cable 1~100M LC-LC Duplex 10G OM4, MMF Fiber Patch Cable
96 Fibers Rackmount Fiber Enclosure 96 Fibers 1U Rackmount Fiber Enclosure loaded with 4 MTP HD Cassettes 2x MTP-12 to Duplex LC/UPC 10G OM4
48 Ports MTP Fiber Enclosure 1U Rackmount FHD Series Fiber Enclosure, Loaded with 4 FAPs (12xMTP)

Pre-terminated Fiber Cabling in Data Center

pre-terminated fiber cabling

Fiber optic cabling and termination usually cost a lot of time and labor during the deployment of data center. Filed fiber optic termination is still being widely used in many data centers. However, with the data center increasingly depending on the high density cabling, fiber cabling and termination in data center becomes will cost more time and money if using the traditional field termination methods. Meanwhile, the fiber optic network is becoming more and more complex, which makes the data center cabling becomes more difficult. The risks of faults caused manual fiber termination will be increased. To solve problems caused by manual operations and meets the high density requirement of the data center, pre-termianted fiber cable assemblies are introduced in data center.

Advantages of Pre-Terminated Fiber Cable Assemblies

Deploying a data center by using field termination methods might need a few days or more. Engineers have to termination a lot of fiber optic links and connect them to the right ports. To ensure there are no wrong links and bad fiber optic splicing joints, a lot of checking should be done. However, pre-terminated fiber cable assemblies, using the plug-and-play designed modules and cables, can largely improve the working efficiency, increase cabling density and decrease the total data center installation cost. In addition, the factory terminated fiber cable assemblies eliminate the need of fiber optic splicing and provide higher performance compared with field terminated fiber optic cables.

MTP cassette application

Pre-Terminated Fiber Cabling Assemblies in 40G/100G Applications

The most commonly used pre-terminated fiber cabling assemblies for 40G/100G high density cabling applications are MTP/MPO fiber cable assemblies including MTP/MPO trunk cable, MTP/MPO harness cable and MTP/MPO cassette. These pre-terminated components can be directly connected to fiber optic network for data transmission. Making good use of these components can largely increase the cabling density and working efficiency in data centers.

MTP/MPO Trunk Cable

MTP/MPO trunk cable is a length of multi-fiber optical cable usually used for backbone transmission in data center. 12-fiber MTP/MPO trunk cable and 24-fiber MTP/MPO trunk cable used for 40G and 100G applications separately.

MTP/MPO trunk cable

There are generally two versions of MTP/MPO trunk cable—single-strand MTP/MPO trunk cable and multi-strand MTP/MPO trunk cable. A multi-strand MTP/MPO trunk cable combines several single-stand MTP/MPO trunk cables together. For example, a 72-fiber MTP/MPO trunk cable, as shown in the following picture, has 6 strands of 12-fiber cables combining together. Each strand is terminated with a 12-fiber MTP/MPO connector.

72-fiber trunk cable
MTP/MPO Harness Cable

MTP/MPO harness cable is a fanout version of MTP/MPO fiber optic cable. A MTP/MPO fiber optic connector is terminated on one end of this cable, the fanout end it terminated several other types of fiber optic connectors which are usually LC fiber connectors. This type of pre-terminated fiber optic cable is generally used for 40G to 10G transmission or 100G to 10G transmission. MTP/MPO harness cables also come into various types, the most commonly used are 12-fiber MTP/MPO to 6 duplex LC harness cable for 40G duplex transmission and 24-fiber MTP/MPO to 12 duplex LC harness cable for 100G duplex transmission.

MTP/MPO harness cable
MTP/MPO Cassette

MTP/MPO cassette is a specially designed box which contains one or more small version of MTP harness cables in side it. Generally there is one or more MTP fiber optic interface on the back rear of a MTP/MPO cassette and several LC interfaces on its front rear. It can be easily installed on the rack for easier cabling as shown in the following picture.


In this way, the fiber optic connections are protected in this box and more fiber optic connections can be added to the data center without worrying about space limitation. The most commonly used are MTP/MPO LGX cassettes. However, driven by increasing need for high density, the size of MTP/MPO Cassette is keeping decrease. HD MTP/MPO cassette (shown in the following picture) is also available in the market for higher cabling density.

HD MTP/MPO Cassette


The pre-terminated fiber cable assemblies help to accelerate the data center deployment, reduce costs and error, and provide great flexibility and scalability. MTP/MPO cabling system as one the most popular pre-terminated fiber cabling solutions can perfectly fit the 40G and 100G applications. The above mentions products is just a really small part of the pre-terminated fiber cable assemblies. If you need more details, please visit FS.COM where you can customize the pre-terminated fiber cable assemblies according to your applications.