Category: Fiber Transceivers

Cisco 40GBASE QSFP+ (quad small form-factor pluggable plus) modules offer customers a wide variety of high-density and low-power 40 Gigabit Ethernet connectivity options for data center, high-performance computing networks, enterprise core and distribution layers, and service provider transport applications. In this post, several different kinds of conectivity options provided by Cisco will be introduced.

Features and Benefits of Cisco 40GBASE QSFP+ Module

Main features of Cisco 40GBASE QSFP+ modules include:

Interoperable with other IEEE-compliant 40GBASE interfaces

Hot-swappable input/output device that plugs into a 40 Gigabit Ethernet QSFP+ Cisco switch port

High-speed electrical interface compliant to the IEEE 802.3ba standard

Compliant to SFF 8436 and QSFP Multisource Agreement (MSA)

Cisco QSFP-40G-SR4-S

Cisco 40GBASE-SR4 QSFP+ module supports link lengths of 100m and 150m respectively on laseroptimized OM3 and OM4 multimode fiber cables. It primarily enables high-bandwidth 40G optical links over 12-fiber ribbon r cables terminated with MPO/MTP multi-fiber connectors. It can also be used in 4x10G mode along with ribbon to duplex fiber breakout cables for connectivity to four 10GBASE-SR optical interfaces. Cisco QSFP-40G-SR4-S is optimized to guarantee interoperability with any IEEE-compliant 40GBase-SR4 module.

Cisco QSFP-40G-CSR4

Cisco 40GBASE-CSR4 QSFP+ module extends the reach of the IEEE 40GBASE-SR4 interface to 300m and 400m respectively on laser-optimized OM3 and OM4 multimode fiber cables. Each 10-gigabit lane of this module is compliant to IEEE 10GBASE-SR specifications. This module can be used for native 40G optical links over 12-fiber ribbon cables with MPO/MTP connectors, or in a 4x10G mode with ribbon to duplex fiber breakout cables for connectivity to four 10GBASE-SR interfaces. The following picture shows a Cisco QSFP-40G-SR4-S QSFP+ module and a Cisco QSFP-40G-CSR4 QSFP+ module.

Cisco QSFP-40G-LR4-S

Cisco 40GBASE-LR4 QSFP module supports link lengths of up to 10 km over a standard pair of G.652 single-mode fiber with duplex LC connectors. QSFP-40G-LR4-S module supports 40GBase Ethernet rate only. 40 Gigabit Ethernet signal is carried over four wavelengths. Multiplexing and demultiplexing of the four wavelengths are managed in the device. QSFP-40G-LR4-S does not support FCoE.

Cisco WSP-Q40GLR4L

Cisco WSP-Q40GLR4L QSFP+ module supports link lengths of up to 2 km over a standard pair of G.652 single-mode fiber (SMF) with duplex LC connectors. 40 Gigabit Ethernet signal is carried over four wavelengths. It is interoperable with 40GBase-LR4 for distances up to 2 kilometers. The following picture shows a Cisco QSFP-40G-LR4-S QSFP+ module and a Cisco WSP-Q40GLR4L QSFP+ module.

Cisco QSFP+ Copper Direct Attach Cables (DACs)

Cisco QSFP+ copper DACs include QSFP+ to QSFP+ copper DACs and QSFP+ to 4SFP+ copper DACs. Cisco QSFP+ copper DACs are suitable for very short distances and offer a very cost-effective way to establish a 40-gigabit link between QSFP+ ports of Cisco switches within racks and across adjacent racks. QSFP+ to 4SFP+ copper breakout DACs cables connect to a 40G QSFP+ port of a Cisco switch on one end and to four 10G SFP+ ports of a Cisco switch on the other end.

Cisco QSFP+ Active Optical Cables (AOCs)

Cisco QSFP+ AOCs include QSFP+ to QSFP+ AOCs and QSFP+ to 4SFP+ AOCs. Active optical cables are much thinner and lighter than copper cables, which makes cabling easier. Active optical cables enable efficient system airflow and have no electromagnetic interference (EMI) issues, which is critical in high-density racks.

fiber-mart.com is a professional manufacturer and supplier for optical fiber products and provides various kinds of 40GBase QSFP+ transceivers branded by many famous companies. Cisco QSFP+ transceivers offered by fiber-mart.com are the most cost-effective standards-based QSFP+ modules fully compatible with Cisco switches and routers. They are 100% compatible with major brands and backed by a lifetime warranty.

40GbE (Gigabit Ethernet) is Ethernet standard developed by the IEEE 802.3ba, enabling the transfer of Ethernet frames at speeds of up to 40 gigabits per second (Gbps). Now 40 Gigabit Ethernet is becoming more and more popular, suitable for high-speed, high-demand, and computing applications. For a 40GbE network, transceiver modules are one of the most basic components for transmission, used to plugged into either network servers or various of components such as interface cards and switches. 40GbE transceivers are being developed along several standard form factors. Some basic knowledge of 40GbE transceivers will be provided in the following text.

The CFP (C form-factor pluggable) transceiver features twelve transmit and twelve receive 10Gbps lanes to support one 100GbE port, or up to three 40GbE ports. Its larger size is suitable for the needs of single-mode optics and can easily serve multimode optics or copper as well. The following picture shows a CFP transceiver. 40GBASE CFP transceiver modules are hot-swappable input/output devices that plug into a 40 Gigabit Ethernet CFP port of a switch or router. CFP modules offer customers versatile 40 Gigabit Ethernet connectivity options in core and distribution layers of data center, enterprise, and service provider networks. Main features of 40GBASE CFP modules include:

Support for 40GBASE Ethernet and OTU3 standards

Support for “pay-as-you-populate” model

Support for digital optical monitoring (DOM)

Variety of interface choices for 40 Gigabit Ethernet connectivity

Interoperability with respective industry IEEE- and/or OTU3-compliant interfaces

Support for the Cisco quality identification (ID) feature, which enables a Cisco switch or router to identify whether the module is certified and tested by Cisco

CXP Transceiver

The CXP transceiver form factor also provides twelve lanes in each direction but is much smaller than the CFP and serves the needs of multimode optics and copper. The Roman number X means that each channel has a transmission rate of 10 Gbps. CXP is a kind of hot-pluggable transceiver with data rate up to 12×10 Gbps. It provides twelve 10 Gbit/s links suitable for single 100 Gigabit Ethernet, three 40 Gigabit Ethernet channels, or twelve 10 Gigabit Ethernet channels or a single Infiniband 12× QDR link. The C is the Roman numeral for 100 as a memory aid.

QSFP/QSFP+ Transceiver

The QSFP/QSFP+ (quad small-form-factor pluggable) is similar in size to the CXP and provides four transmit and four receive lanes to support 40GbE applications for multimode and single-mode fiber and copper today. It is the most popular interface of 40G transceivers now. Two main types of QSFP+ transceivers used in the data center are QSFP-40G-SR4 and QSFP-40GE-LR4. The following picture shows an Arista QSFP-40G-SR4 QSFP+ transceiver and a Cisco QSFP-40GE-LR4 QSFP+ transceiver. QSFP-40G-SR4 is used in 4x10G mode along with ribbon to duplex fiber breakout cables for connectivity to four 10GBASE-SR optical interfaces. 40GBASE-LR4 QSFP+ module supports link lengths of up to 10km over a standard pair of G.652 single-mode fibres with duplex LC connectors. In addition, there are other types of QSFP+ modules, such as QSFP-40G-ER4, 40GBASE-PLRL4, etc. Main features of 40GBase QSFP+ modules include:

Support for 40GBASE Ethernet

Flexibility of interface choice

Hot-swappable input/output device that plugs into a 40-Gigabit Ethernet QSFP+ switch port

Interoperable with other IEEE-compliant 40GBASE interfaces available in various form factors

Support for “pay-as-you-populate” model

Conclusion

fiber-mart.com offers customers a wide variety of high-density 40 Gigabit Ethernet connectivity options for data center, high-performance computing networks, enterprise core and distribution layers, and service provider transport applications.

40G active optical cable (AOC) is a high performance, low power consumption, long reach interconnect solution supporting 40G Ethernet, fiber channel and PCIE. It is widely used in many fields as well as promoting the traditional data center to step into optical interconnection. Compared to 40G copper direct attach cables and 40GBASE QSFP+ optics, what makes 40G AOC so popular?

What Is 40G AOC?

40G AOC, is a type of active optical cable for 40GbE applications that is terminated with 40GBASE QSFP+ transceiver on one end while on the other end, it can be terminated with QSFP+ connector, SFP+ connector, or LC/SC/FC/ST connector. Active optical cable uses electrical-to-optical conversion on the cable ends to improve speed and distance performance of the cable without sacrificing compatibility with standard electrical interfaces. QSFP+ AOC integrates four data lanes in each direction with 40Gbps aggregate bandwidth. Each lane can operate at 10Gbps with lengths ranging from one to 100m. It is compliant with the QSFP MSA and IEEE P802.3ba. The following picture shows the structure of an active optical cable and three different kinds of QSFP+ AOC.

Advantages of 40G AOC

40G AOCs have great advantages over 40G copper DACs and 40GBASE QSFP+ optics. 40G AOCs cost lower than SR4 modules and do not need to use with extra fiber patch cables. In particular, 40G breakout AOCs, such as 40GBASE QSFP+ to 4xSFP+ or 40GBASE QSFP+ to 8xLC AOCs are cost-effective solutions to achieve 40G migration. Additionally, using AOCs, there are no cleanliness issues in optical connector and there is no need to do termination plug and test when troubleshooting, which can help user save more time and money. 40G AOCs achieve longer reach, have lower weight and tighter bend radius, which enables simpler cable management and the thinner cables allows better airflow for cooling. Besides, AOCs have better consistency and repeatability cabling performance. With the integration and sealed design, AOCs can avoid the influence of environment and vibration. Additionally, for troubleshooting, AOCs are more easier to manage. Because users do not need to do a seires of termination plug and test on-site as they do when using SR4 modules and patch cables.

Applications of 40G AOC

40G AOC is commonly used for short-range multi-lane data communication and interconnect applications, for it provides light weight, high performance, low power consumption, low interconnection loss, EMI immunity and flexibility. QSFP AOC supports InfiniBand QDR/DDR/SDR, Ethernet (10 and 40Gbps), Fibre Channel (8 and 10 Gbps), SAS and other protocol applications. AOCs are highly recommended to use in data center interconnection.

The market of active optical cables keeps growing and has a broad prospect. fiber-mart.com AOCs achieve high data rates over long reaches which provide solutions for high-performance computing and storage applications. We offer all kinds of QSFP+ cable and 40G QSFP products with high performance and quality guaranteed.

Fiber optic patch cord is a fiber optic cable capped at both ends with fiber optic connectors to allow it to be rapidly and conveniently connected to telecommunication equipment and to achieve accurate and precise connections. Fiber optic connector is a very important part of the fiber patch cords. This article mainly talks about what fiber optic connector is, four common types of fiber optic connectors and its relationship with fiber patch cords.

What Is Fiber Optic Connector

This question can be answered in two ways. Functionally, a fiber optic connector terminates the end of an optical fiber, and provides a separable connection between two elements of an electronic system without unacceptable signal distortion or power loss. Structurally, every connector includes several parts, two permanent interfaces, the contact springs in each half of the connector, the separable interface and the connector housing which maintains the location of the contacts and isolates them from one another electrically. The connectors mechanically couple and align the cores of fibers so light can pass. To achieve less light loss, more and more better connectors are made to provide more accurate misalignment of the fibers.

Four Common Types of Fiber Optic Connectors

Connector types of the patch cable must match the patch panels and equipment so that the patch cable can function well. There are many different connectors in use for fiber optic patch cords. The text below is a brief overview of four common connector types. The following picture shows some common fiber optic connectors.

LC connector is a small form factor plastic push/pull connector with a 1.25mm ferrule. LC was first developed by Lucent. LC connector has a locking tab and a plastic housing and provides accurate alignment via its ceramic ferrule. LC has been referred to as a miniature SC connector.

SC connector is a plastic push/pull connector with a 2.5mm ferrule. It requires less space in patch panels than screw on connectors. For its low cost, simplicity and durability, SC connector is the second most commonly used type for polarization maintaining (PM) connections. Like LC connector, SC connector also has a locking tab and provides accurate alignment via its ceramic ferrule.

FC connector is a metal screw on connector with a 2.5mm ferrule. It is extensively used at the interfaces of test equipment due to its ruggedness. FC connector is the most common connector used for PM connections. And it features a metal housing, a position locatable notch and a threaded receptacle. FC connectors are nickel-plated.

ST connector is a metal bayonet coupled connector with a 2.5mm ferrule. It can be inserted into and removed from a fiber optic cable both quickly and easily. ST connectors are nickel-plated, keyed, spring-loaded and constructed with a metal housing. It has push-in and twist types.

All these four types of fiber optic connectors have different constructions and their respective applications. And there are many other kinds of fiber optic connectors, such as MU, MTRJ, E2000, SMA, etc. One important criterion for choosing fiber patch cord is to choose one with the most appropriate connector type that meets your needs.

Fiber Optic Connectors and Fiber Patch Cords

Fiber optic connector is an essential part of fiber patch cords. Generally, many fiber optic connectors can be manufactured for both single mode and multi-mode, simplex and duplex fiber patch cables. And fiber patch cord can have the same or different connectors at its both ends. For example, LC-LC single mode simplex fiber patch cord is a single mode simplex fiber patch cable with a simplex LC connector on each end, or SC-LC multi-mode duplex fiber patch cord is a multi-mode duplex fiber patch cable with a duplex LC connector on one end and a duplex SC connector on the other end.

We know that fiber optic patch cables play a very important role in the connection between devices and equipment. When talking about fiber optic patch cables, we usually divide them into multimode fiber optic patch cables and singlemode fiber optic patch cables according to the modes of the cable. What is multimode fiber optic patch cable? How many types of multimode patch cables are there? And what is the difference between multimode and singlemode patch cables? What are the applications of multimode patch cables? This text will solve those questions one by one.

Introduction

Multi-mode fiber patch cables are described by the diameters of their core and cladding. There are two different core sizes of multi-mode fiber patch cords: 50 microns and 62.5 microns. Both 62.5 microns and 50 microns patch cable feature the same glass cladding diameter of 125 microns. Thus, a 62.5/125µm multi-mode fiber patch cable has a 62.5µm core and a 125µm diameter cladding; and a 50/125µm multi-mode fiber patch cable has a 50µm core and a 125µm diameter cladding. The larger core of multi-mode fiber patch cords gathers more light and allows more signals to be transmitted, as shown below. Transmission of many modes of light down a multi-mode fiber patch cable simultaneously causes signals to weaken over time and therefore travel short distance.

Types of Multimode Fiber Optic Patch Cable

Multimode fiber optic cables can be divided into OM1, OM2, OM3, and OM4 based on the types of multimode fiber. The letters “OM” stands for optical multimode. OM1 and OM2 belong to traditional multimode fiber patch cable, while OM3 and OM4 belong to the new generation fiber patch cable which provides sufficient bandwidth to support 10 Gigabit Ethernet up to 300 meters. The connector types include LC, FC, SC, ST, MU, E2000, MPO and so on. Different type of connector is available to different equipment and fiber optic cable.

By the materials of optic fiber cable jackets, multimode fiber patch cord can be divided into four different types, PVC, LSZH, plenum, and armored multimode patch cable. PVC is non-flame retardant, while the LSZH is flame retardant and low smoke zero halogen. Plenum is compartment or chamber to which one or more air ducts are connected and forms part of the air distribution system. Because plenum cables are routed through air circulation spaces, which contain very few fire barriers, they need to be coated in flame-retardant, low smoke materials. Armored fiber patch cable use rugged shell with aluminum armor and kevlar inside the jacket, and it is 10 times stronger than regular fiber patch cable.

Difference Between Singlemode and Multimode Patch Cables

Multimode and singlemode fiber optic patch cables are different mainly because they have different sizes of cores, which carry light to transmit data. Singlemode fiber optic patch cables have a core of 8 to 10 microns. Multimode fiber patch cable allows multiple beams of light passing through, while singlemode fiber cable allows a single beam of light passing through. As modal dispersion happens in multimode fiber cable, the transmission distance is relevantly nearer than singlemode fiber cables. Therefore, multimode fiber optic patch cable is generally used in relevantly recent regions network connections, while the singlemode fiber cable is often used in broader regions.

Applications of Multimode Fiber Optic Patch Cable

Multi-mode fiber patch cables are used to connect high speed and legacy networks like Gigabit Ethernet, Fast Ethernet and Ethernet. OM1 and OM2 cables are commonly used in premises applications supporting Ethernet rates of 10Mbps to 1Gbps, which are not suitable though for today’s higher-speed networks. OM3 and OM4 are best multimode options of today. For prevailing 10Gbps transmission speeds, OM3 is generally suitable for distance up to 300 meters, and OM4 is suitable for distance up to 550 meters.

Conclusion

Fiber optic patch cords are designed to interconnect or cross connect fiber networks within structured cabling systems. Typical fiber connector interfaces are SC, ST, and LC in either multimode or singlemode applications. Whether to choose a singlemode or multimode fiber patch cable, it all depends on applications that you need, transmission distance to be covered as well as the overall budget allowed.

Though fiber optic patch cord is a preferable option in a network, it also has the potential to be the weakest link in fiber network infrastructures. So it is very essential to follow correct procedures in administration of fiber patch cords to achieve optimum performance and reliability. Best practice in managing patch cords can be divided into four parts: planning, preparation, patching, and validation. This post will talk about fiber jumper management from these four aspects.

Planning

A good plan is half the success. Make sure you know the specifications and design of your fiber cabling. Fiber patch cords you choose must match the installed cabling. Do not mix them. Color-coding of connectors for different fiber standards make it easy to avoid confusion. First you need to find the best route between the ports to be connected to establish the correct cord length. This is usually the shortest route through horizontal and vertical cable guides that does not obstruct or interfere with other cords and connectors in the panel. By adding the horizontal and vertical distances, you get the required length. Avoid running cords through cable pathways that are already congested.

When selecting a cord to make a cross connection, avoid excessive slack and provide a neat appearance. Tight cords will pull on connectors and too much slack complicates cord management, making the panel more difficult to work on. Ensure that panels are fitted with correct cable management accessories. In general, a horizontal patch cord management guide is needed for every two rack units, depending on the type of optical patch panel or lightguide interconnect unit (LIU). At the optical patch panel or LIU, route patch cords equally toward both sides of the vertical cable management channels to prevent overloading one side.

Preparation

Before performing administration activities, preparation is critical. It can minimize disconnect time as much as possible. What preparation needs to be done? Locate the ports that must be connected or reconnected. Ensure technicians have clear information on what they need to do, including labeling information for the ports involved. Ensure cords are of the right type and quality, whether an MPO cable or a LC fiber cable or other connector types, and that they are clean and in good condition. Cleanliness is vital in fiber optic connections so special care is needed with connector ends on patch cords, panels and network equipment.

Patching

During the patching process, be careful not to use excessive force during the patching process, which can stress cords and connectors, reducing their performance. And exceeding the bend radius can result in significant additional loss and adverse impact on channel performance. Patching includes removing a patch cord and adding a patch cord. Steps in removing and adding cords:

Removing a patch cord

1. locate the existing circuit

2. unplug the patch cord at one end and cover the connector endface with a dust cap

3. cover the open port with a dust cover

4. gently lift the cord straight up, taking up slack until its movement is detected

5. follow the cord routing, gently removing it along its length from the cable pathways

6. find the other end and unplug it

7. fully remove the cord

Adding a patch cord

1. identify the location of the new circuit

2. plug one end of the patch cord into the fiber coupling

3. route the patch cord

4. locate the new connecting point

5. plug the other end of the patch cord into the fiber coupling

Validation

Patching must be right since mistakes can cause costly disruption and re-work. It is totally necessary and important to take some time to make a final visual check on connections. When patch panels are mounted in enclosures, ensure they are securely closed and, where necessary, locked, making sure that cord slack is not snagged or pinched by the doors. The final step is to update the documentation to the as-built configuration and close the work order associated with the completed change request.

Summary

To sum up, a good fiber cabling management depends on the four aspects above. A right plan, well preparation, careful patching and at last, a thorough validation, all these add up to a successful cable management. You need to make sure that every procedure is properly implemented.