Tag Archives: 40GBASE-SR4

How to Get 40/100G Connectivity in Your Data Centre?

The demand for network growth is rapidly increasing, which is due to the massive amount of storage needed for high bandwidth applications. Large growth hence spurs the requirements for expansion and scalability in the data centre. Cabling infrastructures must evolve to provide reliability, manageability and flexibility. Obviously, the conservative 2-fibre transmission is not enough to catch up with the speed. And 12 or 24-fibre 40/100G Ethernet migration is quickly becoming a matter of survival. This article offers cabling solutions for cost-effective and simplified migration for 40/100G within the data centre.

Introduction to 40/100G Ethernet

40/100G Ethernet employ parallel optics. Parallel optics transmission, compared to traditional serial transmission, uses an optic module interface where data is simultaneously transmitted and received over multiple fibres. For the 40GE transmission, 4 x 10G on 4 fibres per direction and 10 x 10G on 10 fibres per direction for the 100GE. Which ushers the need for the high quality and low loss multimode MTP connectors and assemblies.

How to Get 40G Connectivity?
1). 10G to 40G Connection

Migration from 10G to 40G system utilises 40G MTP/MPO breakout cables, with an MTP/MPO connector on one end and four duplex LC connectors on the other end. The IEEE ratified the 40GBASE-SR4 (MPO/MTP interface) standard that uses 4 lanes at 10G SFP+ (LC interface) per lane over multimode fibre for a total of 8 fibres.

Parallel optics 40GBASE-SR4 uses 8 out of 12 MTP/MPO interfaces fibres transmitting 4 duplex channels (4 for transmit and 4 receive), as shown in the following picture. QSFP+ to SFP+ breakout cable is 8-fibres MTP to LC breakout assembly.

10G-40G migration solution 1

2). 40G to 40G Connection

As for data transmission between two 40G switches, 40G QSFP+ SR4 transceivers are generally adopted, transmitting signals over four duplex 10G lanes (4 transmit and 4 receive). A 12-fibreMTP/MPO trunk are involved, with 8 out of 12 fibres used to achieve 4 duplex signals transmission. And MTP/MPO adapter panels can be installed easily to make the next adaptation, as the following picture indicates.

10G-40G migration solution 2

How to Get 100G Connectivity?
1). 10G to 100G Connection

Migrating from 10G to 100G still utilises 100G MTP/MPO breakout cable, the IEEE ratified the 100GBASE-SR10 (MTP/MPO interface) standard that uses 10 lanes at 10G SFP+ per lane over multiple fibre for a total of 20 fibres. Parallel optics 100GBASE-SR10 uses 20 out of 24 MTP/MPO interface fibres transmitting 10 duplex channels.

10G-100G migration solution 1

2). 100G to 100G Connection

100G connectivity can be achieved through ten 10G SFP+ transceivers. SFP+ transceiver operates on legacy duplex 10G lanes, thus taking full advantage of the existing network infrastructure. With a 24-fibre MTP/MPO trunk cable, of which 20 out of the 24 fibres are used to make duplex 10×10G transmission.

10G-100G migration solution 2

We can also get 100G to 100G connectivity via MTP/MPO assemblies: simply use the 24-fibre MTP/MPO interface trunk cable or 2×12-fibre MTP/MPO interface trunk cable. As shown in the following picture.

40G-100G migration solution 1


With the rapid increase in bandwidth consumption, the migration from 10G to 40/100G is inevitable. The economics of cost per port per 10Gbps is much more favorable for a 40GBASE-SR4 and 100GBASE-SR10 network. All the transceivers and cabling assemblies presented in the solutions are available in FS.COM. For more details, please visit www.fs.com or contact us via sales@fs.com.

Ribbon Cable for 40G/100G Data Centre

Today many factors drives the need for high data rates, such as virtualization, convergence and high-performance computing environments, etc. So more and more servers, routers and network switches will be added to 40G/100G data centres to handle the increased data traffic. Thus, the optical fibre installation needs migration. But what kind of cable is the most suitable for 40G/100G data centres? To answer this question, we have to learn some thing about one of the connectivity equipment–40G/100G transceivers.

Fibre Optical Transceivers

Different data rates need different transceiver modules. There are SFP (small form-factor pluggable), SFP+ modules for 1G and 10G network, and QSFP+ (quad small form-factor pluggable), CFP (centum form-factor pluggable ) for 40G and 100G network. All of theses transceivers have various types according to form factor. For example, 40GBASE-SR4 and 100GBASE-SR4 (as shown in the following picture) are most often used for 40G and 100G. It uses 4 parallel fibres for transmission and 4 lanes.


MPO/MTP Connectors

MPO/MTP connectors are the most prevalent connector type used in the system. Standard 12-fibre MPO are configured. 4 fibres are used for transmission and 4 fibres are used for receive function. The other 4 fibres in the middle are left unused of “dark” fibres.

However, this method may cost more because the fibres are not fully used. If upgrade the system to 100G with a similar 4x25Gbs scheme, the same fibre arrangement can be used. By using conversion harness or interconnect modules, all 12 fibres of a ribbon can be utilised until the interconnection with optical modules is required. The use of ribbons allows for easier connection (less opportunity to cross fibres in an MPO connector), and perhaps more importantly, achieves easier polarization continuity regardless of the polarity method selected for the system.

Comparison Between Ribbon Cable with Armored Versions

Before installing cables, several factors should be considered to decide the cable design. The following will compare ribbon cable with armored versions from the sides of fibre count, cable size, ruggedness of design, and cost.


The fibre density is a very attractive feature of these cables especially as fibre counts increase in the data centre. A 48-fibre cable ribbon design the outside diametre is about 40% of armor design cable of the same fibre count.

Besides, the cable diametre is also important because the cable is often installed in a conduit system. If the installed cable diametres in the conduit are very high, then the cable installation will be problematic. Maybe the installed cables will be damaged. In comparison, to install 3 armored cables and 3 ribbon cables in a conduit respectively, the amount of “headroom” for the installation using a ribbon cable design is evident.

Of course, except the cable size, there are other factors to determine the cable construction. For example, every cable installation is not the same length or has the same number of bends at the same angles. Installation methodologies are different and depending on the length of cable, its weight, tensile strength must also be taken into consideration. Ribbon cables are flexible and strong and less likely to cause problems during the cable pull process.

At last, the cost is often considered for every installation. The ribbon cable is very cost effective with high fibre counts. For ribbon cables, the fibre counts can be 8, 12, 24, 36, 48 and 72 and easily terminated with MPO/MTP connectors.


Ribbon cables have been used in the network for more than 20 years. The above content obviously shows their advantages of fibre density, size and cost. They are specially suitable for 40G/100G data centre builds. In the long run, the ribbon cables are good for future data rate expansion.

Originally published at www.fibre-optic-equipment.com/