March 2017

Saving Data Center Space to the Extreme with MPO Cable Assemblies

25. march 2017 at 5:28 | jack
As data center gradually migrates to higher speed 40G and 100G networks, more and more devices will be crowded in. Space becomes the first factor that IT managers should take into consideration. To solve this issue, FS.COM has released a series of MPO cable assemblies, including HD TAB MPO fiber patch cable, MPO harness cable, MPO breakout patch panel and MPO cassette, etc. which can save space to the extreme in data center. This post will introduce these four high density MPO cabling solutions one by one in detail.

HD TAB MPO Fiber Patch Cable
HD TAB MPO fiber patch cable allows high-density connections between network equipment in telecommunication rooms. It features push-pull tab connectors at both ends that can offer maximum accessibility in high density installations. Besides, Like standard MPO connector, these HD push pull connectors are also the same size of a SC connector, but since it can accommodate 12 fibers, providing up to 12 times the density, thereby offering savings in circuit card and rack space. We can get detailed information of this HD TAB MPO fiber patch cable in the image below.

HD TAB MPO fiber patch cable
MPO Harness Cable
MPO harness cable, normally terminated with MPO connector on one end and several SC or LC connectors on the fanout end, is designed for high density applications with required high performance and speedy installation. In order to increase the capacity of existing 12-fiber and 24-fiber MPO network, MPO harness conversion cable is designed. It can allow users to convert their existing MPO backbone cables to an MPO type which matches their active equipment. Commonly used MPO harness conversion cables are 1*2 MPO conversion cable (one 24-fiber MPO connector at one end and two 12-fiber MPO connector at the other end), 1*3 MPO conversion cable (one 24-fiber MPO connector at one end and three 8-fiber MPO connectors at the other end), 2*3 conversion cable (two 12-fiber MPO connectors at one end and three 8-fiber MPO connectors at the other end). These three MPO harness conversion cable types are shown in the following image.

MPO harness conversion cable
HD MPO Breakout Patch Panel
There are commonly two types of MPO breakout patch panel for high density data center: 40G breakout patch panel and 100G breakout patch panel. Loaded with 12 standard MPO connectors (8-fiber) elite and 48 duplex LC connectors in a 1RU patch panel, 40G breakout patch panel can meet high density cabling demands up to 96 ports. 100G Breakout patch panel is designed with 8 standard 24-fiber MPO connectors (20 fibers used) and 80 duplex LC connectors in a 2RU patch panel, which can achieve 8 groups of 10G to 100G path in a simple, efficient and well-managed way.

HD MPO Breakout Patch Panel
HD MPO Cassette
HD MPO fiber cassette is a modular module, which is loaded with 12 or 24 fibers and have 6 or 12 duplex LC or SC adapters on the front side and MPO adapter at the rear. HD MPO cassette is more compact than the traditional LGX MPO cassette, so that it can be more suitable for high-density applications, helping users saving more spaces. For example, a 1RU fiber enclosure can only hold up to 3 MPO cassettes, but it can hold up to 5 MPO cassettes as shown below.

HD MPO Cassette
As networking equipment becomes denser and port counts in the data center increase to several hundred ports, it is time to deploy MPO cabling assemblies. All of the assemblies we have talked above can be purchased in FS.COM. For any requirement, please visit FS.COM.

Why Should We Choose SMF for Future-Proof Data Center Cabling?

17. march 2017 at 11:11 | jack
When choosing fiber optic cable, users will always be in a delimma: single-mode or multimode, which one should we choose? Although multimode is cheaper in price, many facts indicate that single-mode cabling is better for future-proof data center cabling.

MMF: A Penny Wise but A Pound Foolish
Price is always the first factor that customers will take into consideration when purchasing products. Generally, the SMF itself is cheaper than MMF fiber ($1.10/meter vs. $3.70/meter for 24-strand OS2 vs. OM3 in FS.COM, and if you use SMF with LC interface and MMF with MTP interface for 40/100G, the price difference between SMF and MMF will be much great, 1M LC fiber cable vs. OM3 MPO fiber cable is $2.8 vs. $38 ), but the optics we should use with SMF vs. MMF are usually a bit more expensive. Take FS.COM as an example, SMF SFP vs. MMF SFP is $7 vs. $6, SMF vs. MMF SFP+ is $34 vs. $16, and with the increase of data rates, the price gap between SMF and MMF optics will be widen. We can get more detailed information from the table below.

price differences between SMF and MMF optics

From the price comparison between SMF and MMF cabling. You did save an amount of money to install MMF cabling, but you should consider the data rates that the MMF can support. In fact, in most cases, currently deployed MMF cabling is unable to support higher speeds over the same distance as lower-speed signals as shown in the table below since its cabling support for higher bit rates is limited by its large core size. As data traffic grows and interconnectivity speeds increase, the distance between connections must decrease, so the operators will be forced to constrain either the physical size of the data center or the connection speed between its nodes, which is unacceptable for most growing data centers. Besides, higher transmit rates will appear to meet more bandwidth requirements, IT managers will face with replacing an obsolete fiber plant, which will cause unexpected cabling costs.

supporting transmission distance of MMF
SMF Serves as an Alternative
Unlimited Bandwidth and Longer Distance: Unlike MMF, SMF cabling deployment support unlimited bandwidth, all but eliminating the capacity bottleneck. With unconstrained headroom, operators can safely settle into a network architecture with server interconnects that will scale with the data center. Many large data center operators, like Google and Microsoft have consciously adopted an SFM fiber cabling strategy in order to remove the network connectivity and speed constraints of a MMF plant.

Decreasing Cost: While using SMF cabling has historically been more expensive than using MMF, technologies advances have fundamentally changed the pricing structure. For example, price difference between 100G SMF and MMF optics is great, normally $2800 vs. $400, but there are newly designed 100G SMF optics, like QSFP28 PSM4 and QSFP28 CWDM4 as shown below, which is ideal for use for large data center. As the development of technology, the price for SMF cabling will continue decreasing.

100GBase-PSM4 and 100GBase-CWDM4

Consistency: Single-mode cabling is used for external data center communication. By extending SMF into the data center, operators can leverage a consistent cable plant throughout the data center. Standardizing on a single cable plant will drive down sparing costs and reduce operational overhead.

Choosing SMF or MMF is forcing operators to choose between today and tomorrow. Although MMF provides tempting lower prices, it is not a long-term available solution. Operators should take the advantage of SMF's limitless traffic carrying capacity and signal reach without incurring unnecessary cost overhead.

Polarity A and Polarity B MTP Cassettes Deployment

14. march 2017 at 10:38 | jack
With the widespread deployment of 40G and 100G network, high density modular system has gained much popularity. MTP modular cassette is loaded with factory-installed and tested optical fiber assembly inside to connect the front LC or SC adapter to the back MTP connector adapter, which is often used to interconnect MTP backbones with LC or SC patching. This post aims to introduce how to deploy polarity A and polarity B MTP cassettes correctly.

Polarity A and Polarity B MTP Cassettes Overview
As mentioned, MTP cassette features simplex or duplex port adapters across the front and MTP or MPO adapter across the back as shown below. The MTP adapter mounted at the rear of a cassette defines it as either a polarity A or polarity B cassette. The only differences between polarity A and polarity B MTP cassette is the orientation of the internal MPO/MTP connector with respect to the mating MPO/MTP array cable connector.

MPO MTP cassette structure

The polarity A MTP cassette makes a key-up to key down connection between the internal MPO/MTP connector and the MPO/MTP array cable connector, while the polarity B MTP cassette makes a key-up to key up connection. But we have to pay attention that a polarity B MTP cassette will not allow single-mode angle polish mated pair connections, because the angles of the mating connectors are not complementary.

How to Deploy Polarity A and Polarity B MTP Cassettes in Different Connectivity Methods?
To ensure the proper polarity of array connections using multifiber MPO/MTP components from end-to-end, the TIA 568 standard has defined three methods, known as Method A, Method B, and Method C. In different method, the deployments of polarity A and polarity B are different.

Connectivity Method A: In this connectivity method, a type-A trunk cable is used to connect a polarity A MTP cassette with key-up to key-down MTP adapters on each side of the link, then there is a A-to-B type duplex patch cable on the left and a A-to-A type duplex patch cable on the right as shown below.


Note: 1. Type-A trunk cable is a straight through cable with a key-up MTP connector on one end and a key-down MTP connector on the other end, which makes the fibers at each end of the cable have the same fiber position. For example, the fiber located at position 1 of the connector on one side will arrive at position 1 at the other connector. 2. A-to-A and A-to-B type patch cables are defined by TIA standard, which are terminated with LC or SC connectors to complete an end-to-end fiber duplex connection. Generally, A-to-A type patch cable is a cross version and A-to-B type is a straight version.

Connectivity Method B: In method B, a type-B trunk cable is used to connect a polarity B MTP cassette with key-up to key-up MTP adapters on each side of the link, and there are A-to-B type duplex patch cable used on both ends to achieve the connection between MTP cassettes and other equipment as shown below.


Note: Type-B trunk cable is with two key-up MTP connectors terminated at both ends. So the position 1 of one connector is corresponding to the position 12 of the other connector.

Connectivity Method C: In this method, a type-C trunk cable is used to connector a polarity A MTP cassettes on each side of the link, and then use two standard A-to-B type duplex cables at both ends of the link as shown below.


Note: Type-C trunk cable is similar to type-A trunk cable with one key-up connector and one key-down connector at each end, but in type-C cable, each adjacent pair of fibers at one end is flipped at the other end. For example, the fiber at position 1 on one connector is shifted to position 2 at the other connector, and the fiber at position 2 at one connector is shifted to the position 1 at the other connector, etc.

MTP cassette allows for rapid deployment of high density data center infrastructure as well as improved troubleshooting and reconfiguration during MACs(moves, adds and changes). The text above have introduced connectivity of polarity A and polarity B cassettes in three different connectivity method. We have to figure it out that its deployment is closely related to the other components used in the same method, when deploy it, you should pay much attention to the trunk cable and patch cable type used in different method.

Two Simplest Ways to Get 40G to 40G Connection

9. march 2017 at 10:50 | jack
Technologies revolving around virtualization, cloud computing and big data are requiring more throughput capabilities than ever before, and 10G Ethernet is just not enough to deliver these resources. This is where administrators may run into the challenge of upgrading from 10G to 40G and beyond. This post will introduce how to get 40G to 40G connection through two simplest ways: MTP trunk cable and QSFP+ DAC.

MTP Trunk Cable and QSFP+ DAC Overview
Terminated with MTP fiber connector at both ends, MTP trunk cable is used to connect MTP port modules for high density backbone cabling in data centers and other high dense degree environments. 12-fiber and 24-fiber MTP trunk cables are commonly used in networking applications: 12-fiber MTP trunk cable is normally for 40G Ethernet network, while 24-fiber MTP trunk cable is normally for 100G Ethernet network as shown below.

12-fiber and 24-fiber MTP trunk cable for 40G Ethernet

QSFP+ DAC as shown below is a copper 40GBase twinax cable that comes in either active or passive twinax cable assembly and connects directly into QSFP+ modules, which are permanently attached to both ends of the cable. These QSFP+ connectors are not real modules, since they are without expensive optical lasers. That's why QSFP+ DAC cables are much more cheaper than fiber optic cables.

40G to 40G Connection With MTP Trunk Cable
In this scenario, you can simply use 12-fiber MTP MPO trunk cable and 40GBase-SR4/40GBase-CSR4/40GBase-PLR4/40GBase-PLRL4 QSFP+ transceivers to accomplish a quick connection between two 40G switches as shown below. 40GBase-SR4 and 40GBase-CSR4 are used for 40G transmission in short distances up to 150 m or 400 m over OM4 fibers, respectively. The 40GBase-PLRL4 and 40GBase-PLR4 can support transmission distance over single-mode fiber up to 1.4 km and 10 km respectively. All of these QSFP+ modules can deliver 40G over 4 lanes fibers at 10Gbps per lane. When they deployed with a 12-fiber MTP trunk cable, only 8 fibers will be used (4 for transmit and 4 for receive), leaving the other 4 fibers unused. All these modules can be purchased from FS.COM, and you can choose the right one according to the distance between your two switches.

40G to 40G Connection With QSFP+ DAC
QSFP+ DAC and QSFP+ AOC cables are recommended when the distance between the two 40G switches is very short, normally 10 meters. Unlike the first solution, in this scenario, no QSFP+ modules are required. We just need to plug the QSFP+ connectors into the two QSFP+ interfaced switches within the same racks or across adjacent racks as shown below, and it can work, which is more easy to handle, especially for someone who is new to 40G deployment. FS.COM also provides QSFP+ DAC in active or passive versions (active for link length up to 7, 10 meters, and passive for 1, 3, 5 meters). You can choose the proper one up to your requirement.

40G to 40G connection with QSFP+ DAC
Data center migration to 40G Ethernet is imperative. If you are familiar with network deployment, and has bright budget, you can choose MTP trunk cable to get the 40G connection. If you are a new to 40G, you'd better choose 40G QSFP+ DAC for easy installation and lower investment. Of course, this is just personal suggestion, you can choose the right one according to your practical application.