Cabling Data Center Process: Planning & Implementing its Infrastructure

Today’s data centers are the home to diverse bandwidth-demanding devices, like servers, storage systems, and backup devices which are interconnected by networking equipment. All these devices drive the need for reliable and manageable cabling infrastructure with higher performance and more flexibility for today and future growth. While managing the cabling in data centers, two main processes are included: planning the cabling infrastructure and implementing the cables.

Planning the Cabling Infrastructure

As networking equipment becomes denser, and port counts in data centers increase to several hundred ports, managing cables connected to these devices becomes a difficult challenge. Thus, during planning the cabling infrastructure, it’s wise to do the following:

Choosing Fiber Cable Assembly

This assembly has a single connector at one end of the cable and multiple duplex breakout cables at the other end, an alternative to avoid cable management. The LC (Lucent Connector) -MPO (Multifiber Push-On) breakout cable assemblies are designed to do just that. The idea is to pre-connect the high-density, high- port-count LC equipment with LC-MPO breakout cable to dedicated MPO modules within a dedicated patch panel, reducing equipment cabling clutter and improving cable management. This image below show the LC-MPO breakout cable assembly that consolidates six duplex LC ports into one MPO connection.

breakout

Nowadays, this breakout technology is widely used in 40 Gigabit Ethernet (GbE) applications. Like QSFP-4X10G-AOC10M, this product is the QSFP to four SFP+ active optical breakout cable assembly with the 10m short reach.

Using Color to Identify Cables

Color coding simplifies management and can save you hours when you need to trace cables. Cables are available in many colors (table shown below). For instance, multi-mode fiber (MMF) looks in orange (OM1, OM2) and in aqua (OM3), while yellow is usually the color of single-mode fiber (SMF) which is taken as the transmission media when the required distance is as long as 2km, or 10km . Take WSP-Q40GLR4L for example, this 40GBASE-LR4L QSFP+ transceiver works through SMF for 2km link length.

Color coding

Implementing the Cabling Infrastructure

While implementing the cables, the following tasks should be obeyed by.

Testing the Links

Testing cables throughout the installation stage is imperative. Any cables that are relocated or terminated after testing should be retested. Although testing is usually carried out by an authorized cabling implementer, you should obtain a test report for each cable installed as part of the implementation task.

Building a Common Framework for the Racks

This step is to stage a layout that can be mirrored across all racks in data centers for consistency, management, and convenience. Starting with an empty 4-post rack or two, build out and establish an internal standard for placing patch panels, horizontal cable managers, vertical cable managers, and any other devices that are planned for placement into racks or a group of racks. The INTENTION is to fully cable up the common components while monitoring the cooling, power, equipment access, and growth for the main components in the racks.

A good layout discourages cabling in between racks due to lack of available data ports or power supply ports, allowing more power outlets and network ports than you need. This will save you money in the long run as rack density increases, calling for more power and network connectivity. Using correct length cables, route patch cables up or down through horizontal patch panels alleviates overlapping other ports. Some cable slack may be needed to enable easy removal of racked equipment.

Documentation

Typically, the most critical task in cable management is to document the complete infrastructure: including diagrams, cable types, patching information, and cable counts. It’s advised update the documentation and keep it accessible to data center staff on a share drive or intranet Web site.

Stocking Spare Cables

It’s suggestible to maintain an approximately the same amount on the installed cabling and ports in use, so as to face the environment variation or emergency.

Conclusion

Understanding the above-mentioned information about cabling planning and implementation helps you to have a scalable, dependable and manageable cabling infrastructure in data centers. Fiberstore offers many cable management tools, including fiber termination box, cable ties, and distribution cabinet. For more information about cable management solutions, you can visit Fiberstore.

Why Choose 10GBASE-T Interface for 10GbE Infrastructure?

The increasing availability of virtualization applications and unified networking infrastructure puts extreme input/output (I/O) demands on 1 Gigabit Ethernet (GbE), making data centers facing bandwidth challenges. Deploying 10GbE infrastructure can address these problems by delivering greater bandwidth, simplifying network, and lowering power consumption.

Well, the deployment of 10GbE requires cost-effective solution. In general, there are several 10GbE interfaces to choose from, including CX4, SFP+ fiber, SFP+ Direct Attach Copper (DAC), and 10GBASE-T. As for CX4, it’s an older technology that does not meet high density requirements. Although most deployment chooses SFP+ fiber (eg. F5-UPG-SFP+-R) solution, fiber is in no case cost-effective. Besides, SFP+ DAC is limited by its short reach. In such a case, 10GBASE-T is selected as the less power-consuming and cost-saving solution for 10GbE. This article details at what are the reasons that drive the 10GBASE-T to become the suitable 10GbE media option.

Firstly, let’s figure out what is 10GBASE-T. 10GBASE-T, or IEEE 802.3an-2006, is a standard released in 2006 to provide 10Gbit/s connections over unshielded or shielded twisted pair cables, with distances up to 100 meters (330 ft) with RJ45 connectors. 10GBASE-T cable infrastructure can also be used for 1000BASE-T, allowing a gradual upgrade from 1000BASE-T using auto-negotiation to select which speed to use.

10GBASE-T, CAT6 and CAT6A CablingListed below are several reasons why 10GBASE-T become the 10GbE media option.

Flexibility in Reach

Like other copper network implementations using BASE-T standards, 10GBASE-T works for link lengths up to 100 meters, giving network designers a far greater level of flexibility in connecting devices in the data center. Able to realize flexible reach, 10GBASE-T can accommodate either top of the rack, middle of row, or end of the row network topologies, making server placement even more easy and convenient.

Backward Compatibility

10GBASE-T is backward-compatible with existing 1GbE networks, meaning that it can be deployed based on existing 1GbE switch infrastructures in data centers that are cabled with CAT6 and CAT6A (or above) cabling. In other words, when migrating from 1GbE to 10GbE, 10GBASE-T provides an easy path, saving cost.

Reduction in Power Consumption

In widespread deployment of 10GbE networks using 10GBASE-T interface, one challenge lies in the fact that the early physical layer interface chips (PHYs) consumed too much power. The original gigabit chips were roughly 6.5 Watts per port. With technology improvements, the chips improved from one generation to the next, leading to less 1 W per port for 1GbE interfaces. It’s the same with 10GBASET. And owing to the manufacturing processes, the 10GBASE-T reduction in power consumption has been made possible. The figure below shows the relationship between power consumption and wavelength.

power consumption vs. wavelength

When 10GBASE-T adapters were first introduced in 2008, they required 25 W of power for a single port, and later, power has been reduced thanks to the successive generations of developing newer and smaller process technologies. The latest 10GBASE-T adapters require less than 6 W per port,which makes 10GBASE-T suitable for motherboard integration and high-density switches.

Latency

Depending on packet size, latency for 10GBASE-T ranges from just over 2 µs to less than 4 µs—a much tighter latency range. For Ethernet packet sizes of 512 bytes or larger, 10GBASE-T’s overall throughput offers an advantage over 1000BASE-T. Latency for 10GBASE-T is more than three times lower than 1000BASE-T with larger packet sizes. For those enterprise applications that have been operating for years with 1000BASE-T latency, 10GBASE-T latency only makes things better. Many products designed for Local Area Network (LAN) purposely add small amounts of latency to reduce power consumption or CPU overhead.

Broad use of 10GBASE-T interface simplifies data center infrastructures, making it easier to manage server connectivity while delivering the bandwidth needed for heavily virtualized servers and I/O-intensive applications. As the cost continues to fall, and new technological processes further lower power consumption, all these make 10GBASE-T suitable for integration on server motherboards.

Conclusion

10GBASE-T offers the flexible reach, and its backward compatibility with existing 1GbE networks makes it the ideal cost-effective media option for 10GbE infrastructure. As a professional fiber optic product manufacturer and supplier, Fiberstore provides countless 10GBASE-T transceivers for 10GbE applications. Of course, besides 10GBASE-T, other 10GBASE standard transceivers also available in Fiberstore, such as 10GBASE-ER SFP+ (J9153A). For more information about 10GbE interfaces, you can visit Fiberstore.

Consider Two Things Before Deploying 10 Gigabit Ethernet

Over the years, Ethernet technologies have evolved rapidly and amazingly to meet the never-ceasing requirements of higher bandwidth and faster data transmission speeds for high quality network applications, such as live video and video download with high resolution. Through this great evolution, Ethernet technology standards have been designed, like 10 Gigabit Ethernet (GbE).

After IEEE Standard 802.3ae- 2002 for 10GbE was ratified several years ago, some enterprises have begun to deploy 10GbE in their data centers to support bandwidth-needing applications. Before deploying 10GbE, as matter of fact, there are many things that should attract your attention. Here this article lists two important things you need to consider for a reliable 10GbE deployment: 10GbE cabling choices, and 10GbE transceiver types.

10GbE Cabling Choices

Along with the technological revolution, cables used for transmission also experienced progressive development. There are two physical media available for 10GbE transmission: fiber and copper.

10GbE Fiber Cabling Choices

Fiber cables fall on two classifications: single-mode fiber (SMF) and multi-mode fiber (MMF). In SMF, there is only one path for light, while in MMF light flow through multiple paths. SMF is intended for long distance communication and MMF is used for distances of less than 300 m. Commonly used 10GbE ports designed for SMF are 10GBASE-LR, 10GBASE-ER and 10GBASE-ZR, and the ports specified for MMF are 10GBASE-SR and 10GBASE-LRM. It’s of great importance to choose these ports 10GbE transmission when link lengths matter. For example, you can choose a J9150A transceiver when the required distance is less than 300m. In a word, the form factor options depend on your link lengths.

10GbE Copper Cabling Choices

As the structured cabling techniques become mature, copper cabling technology also grasps the chance to develop itself. And more and more people start to choose copper cables as the medium for 10GbE transmission. 10GBASE-T and SFP+ direct attach cables (DAC) standards symbolize copper applications.

10GBASE-T, or IEEE 802.3an-2006, is a standard released in 2006 to provide 10Gbit/s connections over unshielded or shielded twisted pair cables, over distances up to 100 metres (330 ft). It requires the Cat 7 or Cat 6A to reach 100 meters, but can still work on Cat 6, Cat 5E, or even Cat 5 cable when reduced distances are required.

SFP+ DAC is the latest standard for optical transceivers, and it connects directly into an SFP+ housing. In SFP+ DAC cabling assembly, no optical transceiver is used at each end. A cable was invented with each end physically resembling a SFP+ transceiver, but with none of the expensive electronic components. This creation is known as DAC. Actually, besides 10GbE applications, DAC is also considered as a cost-effective solution to replace fiber patch cables sometimes in 40GbE systems. Like QSFP-H40G-ACU10M, this Cisco 40G cabling product is the QSFP to QSFP direct attach passive copper cable assembly designed for 40G links.

QSFP-H40G-ACU10M ,QSFP to QSFP direct attach passive copper cable assembly

10GbE Transceiver Types

After choosing cables, you need to select devices that connect these cables to your networks. These devices are transceivers. 10GbE has four transceiver types: XENPAK (and related X2 and XPAK), GBIC, SFP and SFP+.

XENPAK is a Multisource Agreement (MSA) that defines a fiber-optic or wired transceiver module which conforms to the 10 Gigabit Ethernet (10GbE) standard of the Institute of Electrical and Electronics Engineers (IEEE) 802.3 working group.

X2 defines a smaller form-factor 10 Gb/s pluggable fiber optic transceiver optimized for 802.3ae Ethernet,ANSI/ITUT OC192/STM- 64 SONET/SDH interfaces,ITUT G.709,OIF OC192 VSR,INCITS/ANSI 10GFC (10 Gigabit Fibre Channel) and other 10 Gigabit applications.X2 is initially centered on optical links to 10 kilometers and is ideally suited for Ethernet,Fibre Channel and telecom switches and standard PCI (peripheral component interconnect) based server and storage connections. X2 is physically smaller than XENPAK but maintains the mature electrical I/O specification based on the XENPAK MSA and continues to provide robust thermal performance and electromagnetic shielding. The 10GB X2 fiber optic transceivers series include X2-10GB-SR, X2-10GB-LR, X2-10GB-ER and X2-10GB-ZR, they are designed based on the X2 MSA and IEEE802.3ae. They’re created for the integrated systems solution provide, fiber optics distributor along with other IT distributors.

SFP+, also called SFP Plus, is short for enhanced small form-factor pluggable, an enhanced version of the SFP that supports data rates up to 16Gbit/s. SFP+ 10GbE transceiver series include SFP+ 10GBASE-SR, SFP+ 10GBASE-LR, SFP+ 10GBASE-ER, and so on. Among these types, 10GBASE-SR is widely used when the required distance is less than 500m. Say SFP-10G-SR, this Cisco 10GBASE-SR SFP+ transceiver listed in Fiberstore is designed to support 10GbE applications with the maximum distance reach of 300m.

Conclusioni

After discussion, maybe you have obtained a better understanding of 10GbE cables and transceivers, which helps you to better choose the right devices for your 10GbE applications. Fiberstore supplies various numbers of 10GbE cables and transceivers which are quality assured. For more information about 10GbE solutions, you can visit Fiberstore directly.

The Evolution of 10GbE Cabling Technologies

Since Ethernet technology is born in 1970s, it has evolved continuously to meet the never-ceasing demands of even faster rates of data transmission, such as 10 Gigabit Ethernet (GbE). Along with this ongoing evolution, the cabling technologies that support the 10GbE applications have also advanced, so as to provide greater bandwidth to transmit data with reasonable cost and decreased complexity. Maybe you have few insights in this evolution. Don’t worry. This text mainly talks about the evolution of 10GbE cabling technologies, including fiber and copper cabling technologies.

The Institute of Electrical and Electronics Engineers (IEEE) 802.3 working group has published several standards regarding 10GbE, including 802.3ae-2002 (fiber -SR, -LR, -ER), 802.3ak-2004 (CX4 copper twin-ax InfiniBand type cable), etc. Actually, the evolution of cabling technologies have walked in step with that of 10GbE standards, especially associated with the difference between IEEE802.3ae and IEEE802.3ak standards.

IEEE802.3ae

Ratified in June 2002, the IEEE802.3ae standard outlined the following port types.

10GBASE-SR—It supports 10GbE transmission over standard multi-mode fiber (MMF) with distances of 33m on OM1 and 86m on OM2. Using 2000 MHz/km MMF (OM3), up to 300-m link lengths are possible. Using 4700 MHz/km MMF (OM4), up to 400 meter link lengths are possible. Like SFP-10G-SR-S (shown below), this Cisco 10GBASE-SR module listed in Fiberstore is able to support up to 300m using OM3 at the maximum data rate of 10.3125Gbps. In addition, SR is the lowest-cost optics (850nm) of all defined 10GbE optics.

SFP-10G-SR-S, supporting 300m link length using OM3

10GBASE-LR—This port type uses higher cost optics (1310nm) than SR and requires more complex alignment of the optics to support 10km link length over single-mode fiber (SMF).

10GBASE-ER—It’s a port type for SMF and uses the most expensive optics (1550nm) lasers, enabling a reach of 40km over engineered links and 30km over standard links.

IEEE802.3ak

Approved in February 2004, this IEEE802.3ak standard only defined 10GBASE-CX4—the first 10GbE copper cabling standard.

10GBASE-CX4—It’s a low-cost 10GbE solution intended for copper cabling with short-distance connectivity. Its affordability and wide availability makes 10GBASE-CX4 ideal for wiring closet and data center connectivity.

The CX4 standard transmits 10GbE over four channels using twin-axial cables which originated from Infiniband connectors and cable. The CX4 standard committee defined that the cables should be tighter in electrical specifications. Therefore, CX4 standard is not appropriate when longer length (>10 Infiniband cable is required. And It’s recommended to use only cables that are designed to meet IEEE 802.3ak specifications.

Another aspect of the CX4 cable is the rigidity and thickness of the cable. The longer the length used, the thicker the cable is. CX4 cables must also be factory-terminated to meet defined specifications.

After comparison between IEEE802.3ae and IEEE802.3ak standards, here goes a picture about the cabling cost and distance considerations.

 cabling cost and distance considerations

Besides IEEE802.3ae and IEEE802.3ak standards, there also exists IEEE802.3an standard. Proposed in November 2002, IEEE802.3an defined 10GBASE-T using unshielded twisted-pair (UTP) style cabling. The goal of this copper standard is to improve the performance and distance of copper cabling at a cost that is lower or similar to fiber.

From the above introduction, the evolution of cabling technologies is associated with the evolution of 10GbE standards. As 10GbE deployment becomes a commonplace, it’s of great importance to make wise cabling strategies.

Conclusion

Spurred by the demand for faster application speeds, cabling technologies evolved to support the 10GbE standards, thus to better accommodate bandwidth-intensive applications and traffic types. With 10GbE technology being pervasive, it’s necessary to understand the the different 10GbE standards and cabling technologies (mentioned above). Fiberstore supplies 10GbE application solutions, transceivers, copper and fiber cables all included, like AFBR-703SDZ-IN2, a 10GBASE-SR SFP+ transceiver. For more information about 10GbE system solutions, you can visit Fiberstore.

Fiber Optic Cable Handling Rules

Contaminated fiber optic cables can often lead to degraded network performance or even failure of the whole system. As such, to ensure that fiber optic cables can yield the best possible results of network performance, and it’s of great significance for network engineers to keep in mind how to handle fiber optic cables. Do you have any ideas? This text gives the guide to fiber optic cable handling rues.

Fiber Optic Cable Elements

Before delving into how to handle fiber optic cables, introduction to their makeup elements is required.

fiber optic cable fiver elements

Fiber optic cable generally consists of fiver elements (figure shown above): the optic core, optic cladding, a buffer material, a strength material and the outer jacket. Commonly made from doped silica (glass), the optic core is the light-carrying element at the center of the cable. Surrounding the core is the optic cladding, whose combination with the core makes the principle of total internal reflection possible. Surrounding the cladding is a buffer material used to help shield the core and cladding from damage. A strength material surrounds the buffer, preventing stretch problems when the fiber cable is being pulled. The outer jacket is added to protect against abrasion, solvents, and other contaminants.

The outer jacket on fiber optic patch cord is often color-coded to indicate the fiber types being used. For instance, multi-mode fiber (MMF) is usually in orange to distinguish from the color yellow for single-mode fiber (SMF) through which fiber optic transceivers realize relatively long distance, such as MGBLX1. This Cisco 1000BASE-LX SFP transceiver is able to achieve 10km link length over SMF.

Cisco 1000BASE-LX SFP, SMF

Fiber Optic Cable Handling Rules

Despite its outer protection mentioned above, fiber optic cable is still prone to damage. In such as case, a series of fiber cable handing rules are made to ensure that a cable is handled properly, so as to maintain the optimized performance, minimum insertion loss and safe working environments.

Rule 1: The exposed fiber end from coming in contact with all surfaces should be protected. If you contact the fiber with hard surfaces, then the end of it shall be scratched or chipped, causing the degraded performance.

Rule 2: It’s highly recommenced to lean the connector (plug) end each time it is inserted into an adapter, since since a dirty connector will contaminate an adapter.

Rule 3: If a fiber needs to be pulled, use the connector strain relief. Directly pulling on the fiber may result in the glass breaking.

Rule 4: It’s ill-advised to use your hands to clean a fiber work area. If you use your hands to wipe clean a work area, a piece of glass may get lodged into your hands. Considering the size of the glass, this glass may not be visible to the naked eye, bringing about eye damage.

Rule 5: If possible, always keep a protective cap on unplugged fiber connectors, because covering the adapters and connectors will help to avoid contamination and collection of residue. Besides, store unused protective caps in a resealable container in order to prevent the possibility of the transfer of dust to the fiber. Locate the containers near the connectors for easy access.

dust cap covers for protection

Rule 6: It’s suggestible to use fiber-cleaning materials only once. If optic grade wipes are used to clean the fiber end, they should be discarded immediately after the fiber surface has been wiped to avoid contamination.

Rule 7: The minimum bend radius of the fiber optic cable must be maintained. Surpassing the bend radius may cause the glass to fracture inside the fiber optic cable. Equally, to cause a twist of the cable is also not proposed.

Rule 8: Never look into a fiber while the system lasers are on. Eye damage may occur if you stare directly at a fiber end which is working. Always make sure that the fiber optic cables are disconnected from the laser source, prior to inspection.

After discussion, these handling rules may help you to deal with fiber optic cables and improve your network performance.

Conclusion

Proper handling procedures for fiber optic cables are needed to eliminate the possibility of being contaminated or damaged, and provide a clean environment for the network system. Fiberstore supplies many different types of fiber optic cables with high quality for various applications, like MTP cable. You can visit Fiberstore for more information about fiber optic cables.

CAT5 – Copper Network Solutions Choice

Defined by the Electronic Industries Association and Telecommunications Industry Association (commonly known as EIA/TIA), CAT5 (Category 5) cable is the copper wiring using twisted pair technology, designed for Ethernet networks. The term “Category” refers to the classifications of UTP (unshielded twisted pair) cables. Since its inception in the 1990s, CAT5 has become one of the most popular types of of all twisted pair cable types which include CAT3, CAT4, CAT5, CAT6, etc. This article details CAT5 used in copper networks from its working principles, its standard, as well as its installation considerations.

How CAT5 Cable Technology Works

CAT5 is widely used in 100BASE-TX and 1000BASE-T Ethernet networks. CAT5 typically contains four pairs of copper wire. In 100BASE-TX standard, the signals are transmitted across only two of the CAT5 pairs. One pair is used to transmit signals, and the second pair receives the signals, leaving the other two unused in signal transmission. What’s more, the 100BASE-TX signals only run in one direction across the pairs. As technology advanced, the 1000BASE-T Gigabit Ethernet (GbE) standard was developed. 1000BASE-T standard utilizes all four copper pairs to transmit up to 250 megabits of data per second (Mbps) in full duplex transmission across each pair. That is to say, each pair is able to transmit and receive signals simultaneously. 1000BASE-T modules (eg. GLC-T) functioning over CAT 5 with RJ-45 connector achieve full duplex transmission with link length up to 100m (328ft).

GLC-T, functions over CAT 5 with RJ-45 connector

There are two standards for CAT5 wiring, EIA/TIA-568A and EIA/TIA-568B. The following passages mainly discuss EIA/TIA-568A.

EIA/TIA-568A

The TIA-EIA-568-A standard defined the following three main parameters for testing Category 5 cabling installations: wiremap, attenuation, and Near End Crosstalk (NEXT).

Wiremap is a continuity test. It assures that the conductors that make up the four twisted pairs in the cable are continuous from the termination point of one end of the link to the other. This test assures that the conductors are terminated correctly at each end and that none of the conductor pairs are crossed or short-circuited.

Attenuation is the loss of signal, as it is transmitted from the end of the cable to the opposite end at which it is received. Attenuation, also referred to as Insertion Loss, is measured in decibels (dB). For attenuation, the lower the dB value is, the better the performance is, and of course less signal is lost. This attenuation is typically caused by absorption, reflection, diffusion, scattering, deflection.

Near End Crosstalk (NEXT) measures the amount of signal coupled from one pair to another within the cable caused by radiation emission at the transmitting end.If the crosstalk is great enough, it will interfere with signals received across the circuit. Crosstalk is measured in dB. The higher the dB value, the better the performance, more of the signal is transmitted and less is lost due to coupling.

NEXT: the amount of signal coupled from one pair to another

CAT5 Installation Considerations

After testing parameters are mentioned above, here goes the notes of CAT 5 installation.

  • Never pull CAT5 copper wire with excessive force. The CAT5 tension limitation is 25 lbs, much lower than standard audio/video cable.
  • Never step on, crush, or crimp CAT5.
  • Avoid periodic sags; vary the intervals if the cable must sag.
  • Do not bend CAT5 wire tightly around a corner; ensure that it bends gradually, so that a whole circle would be at least two inches in diameter.
  • Do not allow knots or kinks, even temporarily.
  • Never run CAT5 parallel to power wiring closer than six inches.
  • Avoid splices. Every splice degrades the line.
Conclusion

Although CAT5 is superseded by CAT5e in many applications, most CAT5 cable meets Cat5e standards and it’s still a commonplace in Local Area Networks (LANs). Many copper networks choose CAT5 as their transmission media because of its low price and high performance. Fiberstore supplies many CAT5 RJ45 pluggable modules, like 100BASE-TX, and 1000BASE-T transceivers (eg. SFP-GE-T). For more information about copper network solutions, you can visit Fiberstore.

SFP+ Optical Transceiver Testing Introduction

Owing to its ubiquity, simplicity and low cost, Ethernet, one technology enabling Internet communications, is everywhere, from carrier networks to local area networks, from desktop PCs to the largest supercomputers. And with its widespread deployment, there occurs countless equipment accordingly designed for Gigabit communications, such as SFP+ transceiver. Are you familiar with SFP+? How much do you know about its testing challenges? This text will discuss its key features firstly, and then delve into SFP+ optical transceiver testing challenges.

SFP+ Optical Transceiver Background

As an enhanced version of the small form-factor pluggable (SFP), the enhanced SFP (SFP+) is a hot-pluggable, small-footprint, and multi-rate optical transceiver accessible for up to 16 Gbit/s data communications and storage-area network (SAN) applications. And this SFP+ enjoys the following advantages.

Smaller, Cheaper, More Efficient

Just as the last paragraph mentioned above, the SFP+ module is a variant of the SFP optical transceiver. It simplifies the functionality of the 10G optical module significantly by moving functions, such as clock and data recovery (CDR), electronic dispersion compensation (EDC), 10G SERDES, and signal conditioning. Thus, the SFP+ module requires fewer components, consumes less power, and allows for increased port density. Certainly, it’s also smaller and less expensive compared with the 10-Gigabit small form-factor pluggable module (XFP) form factor.

SFP+ Optical Transceiver testing

As SFP+ becomes more prevalent, it’s imperative for engineers to become familiar with some of the key challenges linked to testing SFP+ capable devices.

SFP+ Optical Transceiver Testing Challenges

On one hand, SFP+ gives a hand in reducing the overall system cost. On the other, its physical layer (PHY) and performance are put with new burdens. The SERDES framer interface (SFI) between the host board and the SFP+ module displays great design and testing challenges.

  • One challenge attributes to the increased port density and the testing time required for 48 or more ports per rack. For instance, there are 15 measurements each for the host transmitter tests, and each of these measurements using manual methods can easily take from three to five minutes. This means it will take engineers more than an hour per port to complete the required tests.
  • The second one that engineers need to consider is: if a measurement fails, how can they determine which component is causing such a failure, and how they debug the issue to arrive at the root cause. Such determinations are especially challenging because of the tight physical packaging and compact designs.
  • Another challenge falls on the connectivity. That is: how to get the signal out from the device under test (DUT) to an oscilloscope. Test fixtures are typically required, but questions arise around consequently: whether the fixtures have been tested and validated against the specification.
  • The additional problem lies in the fact that the SFP+ specification requires some measurements to be performed using a PRBS31 signal. At a sampling rate of 50 Gsamples/s, the designer can acquire around 40 million unit intervals (UIs). At a sampling rate of 100 Gsamples/s, the instrument can acquire 20 million UIs. However, a PRBS31 pattern has more than 2 billion UIs. Hence, acquiring an entire pattern poses a challenge.

Conclusion

SFP+ transceiver with its compact size has become a popular industry format supported by many network component vendors. And with the above-mentioned points in mind, designers have gained an overview of SFP+ optical transceiver testing challenges. Fiberstore is an outstanding and professional SFP+ manufacturer and supplier, available with a sea of high-performance and -quality SFP+ transceivers. Besides SFP+transceiver, Fiberstore also supplies QSFP+ transceiver, fully compatible with major brands. For more information about transceivers, you can visit Fiberstore.

For 40GBASE-LR4 QSFP+ Transceiver Link: CWDM or PSM?

Nowadays, the 40 Gigabit Ethernet (GbE) system comes as the popular deployment among some enterprises for their high-performance fiber optic networks. And for 40GbE system, fiber optic transceivers are the indispensable high-capacity modules for multi-lane communications, like 40GBASE-LR4 QSFP+ transceiver. It’s known that 40GBASE-LR4 QSFP+ transceiver has two link options: coarse wavelength division multiplexing (CWDM) and parallel single-mode fiber (PSM). How much do you know about them? Can you figure out the differences between them? Following this article and you will get something.

40GBASE-LR4 CWDM QSFP+ Transceiver Brief

Compliant to 40GBASE-LR4 (eg. QSFP-40G-LR4) of the IEEE P802.3ba standard, this 40GBASE-LR4 CWDM QSFP+ transceiver uses a duplex LC connector as the the optical interface, able to support transmission distance up to 10km over single-mode fiber (SMF) used to minimize the optical dispersion in the long-haul system.

This kind of 40GBASE-LR4 QSFP+ transceiver converts 4 inputs channels of 10G electrical data to 4 CWDM optical signals by a driven 4-wavelength distributed feedback (DFB) laser array, and then multiplexes them into a single channel for 40G optical transmission, propagating out of the transmitter module from the SMF. Reversely, the receiver module accepts the 40G CWDM optical signals input, and demultiplexes it into 4 individual 10G channels with different wavelengths. The central wavelengths of the 4 CWDM channels are 1271, 1291, 1311 and 1331 nm as members of the CWDM wavelength grid defined in ITU-T G694.2. Each wavelength channel is collected by a discrete photo diode and output as electric data after being amplified by a transimpedance amplifier (TIA).

CWDM QSFP+, 2 optical SMFs with a duplex LC connector

40GBASE-LR4 PSM QSFP+ Transceiver Brief

Differently, PSM QSFP+ is a parallel single-mode optical transceiver and uses a MTP/MPO fiber ribbon connector instead of LC. Similarly, PSM QSFP+ also offers 4 independent transmit and receive channels, each capable of 10G operation for an aggregate data rate of 40G with 10km reach over SMF.

In a PSM QSFP+, the transmitter module accepts electrical input signals, while he receiver module converts parallel optical input signals via a photo detector array into parallel electrical output signals. Both the input signals and output signals are compatible with common mode logic (CML) levels.

PSM QSFP+, 8 optical SMFs with a MTP/MPO fiber ribbon connector

CWDM vs. PSM

Allowing for the transceiver module structure, PSM seems more cost effective, since it uses a single uncooled CW laser which splits its output power into four integrated silicon modulators. Additionally, its array-fiber coupling to a MTP connector is relatively simple.

However, when taking the infrastructure into consideration, PSM would be more expensive when the link distance is long, because it uses 8 optical single-mode fibers while CWDM only uses 2 optical single-mode fibers. Besides, in the data center fiber infrastructure, the patch panel has to be changed to accommodate MTP cables, which would cost more than LC connectors and regular SMF cables. Besides, it’s a little difficult to clean MTP connectors. So CWDM is more ideal for 40GBASE-LR4 QSFP+ link.

Conclusion

For 40GBASE-LR4 QSFP+ transceiver link options, both CWDM QSFP+ and PSM QSFP+ support the maximum transmission distance of 10km. The former establishes 40G links over 2 optical SMFs with a duplex LC connector, and the latter achieves 40G links via 8 optical SMFs with a MTP/MPO fiber ribbon connector. Thus no change is required for migration from 10G infrastructure to 40G infrastructure, saving cost when CWDM QSFP+ is chosen. Fiberstore supplies a broad selection of 40GBASE-LR4 QSFP+ transceivers which are fully compatible with major brands, such as Finisar (FTL4C1QE1C). For more information about 40GBASE-LR4 QSFP+ transceivers, please visit Fiberstore.

MPO/MTP Cable Assembly Solutions From FS.COM

The increasing demands for high fiber counts and limited cabling space in today’s data centers have driven the evolution of multi-fiber technology. MPO/MTP technology with multi-fiber connectors serves as a practical optical solution to support high network performance in data centers to accommodate the current and future requirements. Many MPO/MTP products are available in telecommunication market, like MPO/MTP fiber cables, MPO/MTP cassettes, MPO/MTP connectors. This article will introduce MPO/MTP cable assemblies and solution in data centers.

MPO/MTP System Introduction

The term MTP is a registered trademark of US Conec used to describe their connector. MTP cable assemblies are designed and introduced as a performance version of MPO connectors. MTP does interconnect with the MPO connectors. Each MTP connector contains 12 fibers or 6 duplex channels in a connector that is smaller than most duplex connections in use today. A 72-fiber trunk cable can be terminated with six MTP connectors.

MPO/MTP fibers are manufactured with outstanding optical and mechanical properties, allowing high-density connections between network equipment. When easy insertion and removal of a MPO/MTP fiber is required, just a simple push-pull latching mechanism is used in manufacturing MPO/MTP patch cord. That is called Push-Pull tab MPO patch cord. This kind of MPO patch cord with Push-Pull tab offers maximum accessibility in high-density installations, easy insertion and removal with only one hand.

Push-Pull tab MPO patch cord, easy for operation

MPO/MTP Cable Assemblies Features

MTP brand cable assemblies are multi-fiber patch cords suitable for high-density back plane and PCB solutions. There are mainly two configurations for MTP cable assemblies. The most commonly-used one is a MTP connector to MTP connector trunk cable that connects a MTP cassette to another MTP cassette. The other one is MTP connectors to LC or other connector.

MTP trunk cable, as a permanent link connecting the MTP modules to each other, is available in 12-144 counts, intended for high-density application. Using MTP trunk cables, a complete fiber optic backbone can be installed without any field termination.

MTP fan-out cables, also known as harness cables, provide connection to equipment or panels that are terminated with ST, SC connectors. Such assemblies are available pre-wired into patch panels and wall enclosures, able to meet a variety of fiber cabling requirements.

MPO/MTP Cable Assemblies Applications

MPO/MTP cable assemblies are suitable for high-density switch to patching and distribution in data center applications. Their compact design addresses high fiber count applications with small and lightweight cables ideal for applications in which installation space is limited. Besides, the MPO/MTP connector is the standard for delivery of 40G (in its 12 fiber version) and 100G (in either a duplexed 12 fiber cable or 24 fiber ferruled cable) using QSFP transceivers. In 40G applications, take QSFP-40G-SR4-S for instance, this Cisco QSFP-40G-SR4-S QSFP+ transceiver establishes 40G links with the 12 fiber MPO connector assembly.

QSFP-40G-SR4-S for 40G links with the 12 fiber MPO connector

About FS.COM MPO/MTP Cable Assembly Solutions

As a leading fiber optical product manufacturer and supplier, as well as a third party, FS.COM follows customers closely to understand their taste and better meet their requirements. FS.COM supplies high quality MPO/MTP assemblies available in both single-mode and multi-mode versions, in trunk and fan-out types, which are sold at the competitive prices. Besides, Push-Pull tab MPO patch cord (one type of Push-Pull patch cords), which allows easy installation and removal of cables, can also be found in FS.COM.

Conclusion

MTP/MPO cable assemblies help customers to save time, space and cost, while providing high density, suitable for data centers, telecommunications, and broadcast communication applications. In FS.COM, you find the right MTP/MPO cable assemblies for your network performance. Additionally, these products can also be customized upon your request. You can visit FS.COM for more information about MTP/MPO cable assembly solutions.

Establishing 40G Links With OM3 and OM4

To meet the needs of Internet users, the business users in particular, who require faster speeds, greater scalability, and higher levels of network performance and reliability, data centers have experienced infrastructure transformation, from 10 Gbps to 40 Gbps and then to 100 Gbps, or even higher, never-ceasing. Actually, during this bandwidth migration, 40G provides an efficient use of hardware and a more logical upgrade path to 100G. And in establishing 40G links, fiber optic cabling, (eg OM3 and OM4) has become an integral part of the overall system design.

Background Information

The Institute of Electrical and Electronics Engineers (IEEE) 802.3ba 40/100G Ethernet Standard was ratified in June 2010 to support the fast-growing demands for bandwidth in data centers. The standard provides specific guidance for 40G/100G transmission with multi-mode fibers (MMFs) and single-mode fibers (SMFs). OM3 and OM4 are the only approved multi-mode fibers included in this standard.

Using OM3 and OM4 for 40G Links

The IEEE 802.3ba only specified OM3 for a maximum reach of 100 m in its original draft. Later, efforts have been made to win the approval to include OM4 in the standard. As a matter of fact, OM4 can achieve the greater reach of 150 m compared with OM3. In 40 GbE transmission which uses MMFs, an optic module interface is used for the simultaneous data transmission and data reception. Like JNP-QSFP-40G-LX4, this Juniper Networks proprietary 40G-LX4 transceiver listed on FS.COM realizes 100 m transmission on OM3, and 150 m transmission on OM4. Besides, JNP-QSFP-40G-LX4 can also run over SMF for 2 km link lengths.

, transmission media :SMF ,MMF

Evaluating OM3 and OM4 Performance

When evaluating the performance of the OM3 and OM4 cabling infrastructure for 40GbE transmissions, three aspects should be taken into consideration: bandwidth, channel connector insertion loss (CIL) and skew.

  • Bandwidth

In the standard, the bandwidth is ensured by meeting the effective modal bandwidth (EMB) specification. The EMB measurement techniques utilized nowadays are effective modal bandwidth calculate (EMBc) which combines the properties of both the source and fiber. The EMBc process predicts source-fiber performance by integrating the fundamental properties of light sources with the MMF’s modal structure which has been measured using a standardized differential modal delay (DMD) measurement. Within 40G links using OM3 and OM4 fibers measured by the EMBc technique, the optical infrastructure shall meet the performance criteria set forth by IEEE for bandwidth.

  • Channel Insertion Loss (CIL)

CIL is a critical performance parameter in current data center cabling deployments. It refers to the total insertion losses that happen when the signal moves along a fiber optic cable. Within a system channel, CIL impacts the ability to operate over the maximum distance at a given data rate. With total connector loss increasing, the maximum distance at that given data rate decreases. The 40/100G standard specifies the OM3 to a 100m distance with a maximum channel loss of 1.9dB, while OM4 is specified to a 150m distance with a maximum channel loss of 1.5dB.

  • Skew

Skew is classified as the difference between the arrival times of simultaneously launched light signals traveling through parallel cable lanes. When evaluating OM3 and OM4 performance for 40applications, selecting one that meets the 0.75ns skew requirement can ensure the performance.

Establishing 40G Links With OM3 and OM4

40G is deployed using eight of the twelve fibers in a MPO connector. Four of these eight fibers are used to transmit while the other four to receive. Each Tx/Rx is operating at 10G. The 40GBASE-SR4 (eg. QFX-QSFP-40G-SR4) interface is as follows: 4 x 10G on four fibers per direction.

40GBASE-SR optical lane: 4 x 10G on four fibers per direction

OM3 and OM4 for 40G connectivity provide a significant value proposition when compared to SMF, as MMF utilizes low cost 850nm transceivers for serial and parallel transmissions. OM3 and OM4 ensure today’s bandwidth needs.

Conclusion

To continue to accommodate the bandwidth needs, OM3 and OM4 are the ideal solution for 40G links in the data center. FS.COM offers broad selections of OM3 and OM4 fibers of high quality, as well as fiber optic transceivers working over OM3 and OM4, such as JNP-QSFP-40G-LX4 and QFX-QSFP-40G-SR4 mentioned above. You can visit FS.COM for more information about OM3 and OM4, MMF.