Transceiver Solutions for Migrating to 40G Network

As the need for increased network bandwidth to meet the global IP traffic demand is growing rapidly, there is an urgent need for upgrading to 40G Ethernet links in data centers. And the IEEE 802.3ba committee has already ratified the 40 Gigabit Ethernet standard and along with the general specification, defining a number of fiber optic interfaces. These standard interfaces attempted to satisfy a number of different objectives including support for multi-mode fiber (MMF) and single mode fiber (SMF) compatibility. Therefore, there appears various transceiver solutions for migrating to 40G Ethernet network. Among these solutions, there are three popular ones: 40G LR4 QSFP+ transceiver, 40G SR4 QSFP+ transceiver and 40G QSFP+ BiDi transceiver. This article will give a comprehensive comparison on them.

40G LR4 QSFP+ Transceiver

40G LR4 QSFP+ transceivers are hot-swappable Ethernet optical transceivers that support high-speed serial links over single mode optical fiber. With built-in optical multiplexing and de-multiplexing, this kind of transceiver has four channels of 10G multiplexed/de-multiplexed inside the module to transmit and receive an aggregate 40G signal over a single pair (2 strands) of fiber. Used with LC connectors and single mode fiber, 40G LR4 QSFP+ transceivers’ transmission distance can cover around 10km.

As 40G LR4 QSFP+ transceivers can be used together with LC connectors, they may use existing duplex fiber infrastructure for 40G migration. That’s to say, 40G LR4 QSFP+ transceivers can offer a very cost effective connectivity solution and unique value proposition for data centers to migrate from 10G to 40G Ethernet network with minimal disruption with existing fiber optical infrastructure. The main disadvantage of 40G LR4 QSFP+ transceivers is that the optical link may not be as simple as that of 40G LR4 QSFP+ transceivers. The following is a picture of Finisar FTL4C1QE1C compatible 40GBASE-LR4 QSFP+ transceiver.

40G SR4 QSFP+ Transceiver

40G SR4 QSFP+ transceivers are parallel fiber optical module with four independent optical transmit and receive channels. Each of these channels is capable of a 10G operation for an aggregate data rate of 40G. These transceivers use MTP/MPO connectors and require multi-mode OM3 or OM4 cables. They can support with a link length up to 100 meters on OM3 cable and 150 meters on OM4 cable.

40G SR4 QSFP+ transceivers use fundamentally different connectivity formats, requiring fiber cabling infrastructure to be redesigned and replaced. Thus, they cannot reuse aggregation fiber infrastructure built for 10-Gbps connectivity. The following is a picture of Cisco QSFP-40G-SR4 compatible 40GBASE-SR4 QSFP+ transceiver.

40G QSFP+ BiDi Transceiver

40G QSFP+ BiDi transceivers are the lasted products used in 40G transmission. They are transceivers that transmit full-duplex 40-Gbps traffic over one dual-fiber LC-connector OM3 or OM4 MMF cable. 40G QSFP+ BiDi transceivers have two 20Gbps channels, each transmitted and received simultaneously over two wavelengths on a single MMF strand. The result is an aggregated duplex 40Gbps link over a MMF duplex LC-terminated fiber cable. The connection can reach 100 meters on OM3 MMF or 150 meters on OM4 MMF, which is the same as 40Gbps SR4. The following figure shows the technology concept of the Cisco QSFP BiDi transceiver.

To accommodate an ever increasing spectrum of 40 Gigabit Ethernet applications, Fiberstore offers various 40GBASE QSFP+ transceiver types, suitable for different media and distance reaches. All of our QSFP+ transceivers are tested in-house prior to shipping to ensure that they will arrive in perfect physical and working condition. We offer our customers with high-performance and cost-effective products to fulfill their requirements, contributing this way to the customer's success and satisfaction.

The Basics of 40GBASE-LR4 QSFP+ Transceiver

40GBASE QSFP+ (quad small form factor pluggable) portfolio offers 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, etc. And each kind of 40GBASE QSFP+ transceiver has its special applications. 40GBASE-LR4 QSFP+ transceiver is a common 40 Gigabit Ethernet connectivity option. Here is some basic information about 40GBASE-LR4 QSFP+ transceiver.

Introduction

40GBASE-LR4 QSFP+ module supports link lengths of up to 10 kilometers over a standard pair of G.652 single-mode fiber with duplex LC connectors. The 40 Gigabit Ethernet signal is carried over four wavelengths. Multiplexing and demultiplexing of the four wavelengths are managed within the device. The letter "L" stands for long, the "R" denotes the type of interface with 64B/66B encoding and the numeral 4 indicates numeral 4 indicates that the transmission is carried out over a ribbon fiber with four singlemode fibers in every direction. Each lane has a 10 Gbit/s data rate. 40GBASE-LR4 QSFP+ transceiver modules are compliant with the QSFP+ MSA and IEEE 802.3ba 40GBASE-LR4. The picture below shows a Mellanox MC2210511-LR4 compatible 40GBASE-LR4 QSFP+ transceiver.

Two Types of 40GBASE-LR4 QSFP+ Transceiver

There are mainly two of 40GBASE-LR4 QSFP+ transceivers, 40GBASE-LR4 CWDM (coarse wavelength division multiplexing) QSFP+ transceiver and 40GBASE-LR4 PSM (parallel single-mode fiber) QSFP+ transceiver. This part mainly talks about these two 40GBASE-LR4 QSFP+ transceiver types.

40GBASE-LR4 CWDM QSFP+ transceiver, such as QSFP-40GE-LR4, contains a duplex LC connector for the optical interface. It can support transmission distance of up to 10km. A 40GBASE-LR4 CWDM 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 multiplexes them into a single channel for 40G optical transmission. Then the receiver module accepts the 40G CWDM optical signals input, and demultiplexes it into 4 individual 10G channels with different wavelengths.

40GBASE-LR4 PSM QSFP+ transceiver is a parallel single-mode optical transceiver with an MTP/MPO fiber ribbon connector. It also offers 4 independent transmit and receive channels, each capable of 10G operation for an aggregate data rate of 40G. The transmitter module accepts electrical input signals compatible with common mode logic (CML) levels. All input data signals are differential and internally terminated. The receiver module converts parallel optical input signals via a photo detector array into parallel electrical output signals. The receiver module outputs electrical signals are also voltage compatible with CML levels.

Applications

QSFP-40GE-LR4 supports 40GBASE Ethernet rate only, whereas the QSFP-40G-LR4 supports OTU3 data rate in addition to 40GBASE Ethernet rate. 40GBASE-LR4 QSFP+ transceivers are most commonly deployed between data-center or IXP sites with single mode fiber.

Fiberstore offers customers a wide variety of 40GBASE-LR4 QSFP+ transceivers for your high-density and low-power 40 Gigabit Ethernet connectivity options, including 40GBASE-LR4 CWDM QSFP+ transceiver and 40GBASE-LR4 PSM QSFP+ transceiver, like Cisco QSFP-40GE-LR4 40GBASE-LR4 QSFP+ transceiver. Fiberstore also provides wide brand compatible 40G QSFP+ transceivers, such as Brocade QSFP+, Dell QSFP+, Juniper QSFP+, Mellanox QSFP+, and HP QSFP+. Each fiber optic transceiver provided by Fiberstore has been tested to ensure its compatibility and interoperability. Please rest assured to buy.

Are You Ready for 40G and 100G?

Data centers regularly undertake their own great migration, to ever higher speed networks. 10G, unimaginable a decade ago, is now common in larger enterprises. And now many enterprises have to adopt 40 Gigabit Ethernet or even 100G in the aggregation and core layers of data center networks in order to meet the overall bandwidth demands of top-of-rack servers. The need is clear: a 40/100G Ethernet migration plan is quickly becoming a matter of survival. Is your network cabling optimized for this inevitable growth? Are you ready for 40G and 100G?

Fiber Transmissions at Higher Speeds

When moving to 40/100GbE, the most important difference in backbone and horizontal multimode applications is the number of fiber strands. 40GBASE-SR4 uses 8 strands in total, 4 strands to transmit and 4 to receive. 100GBASE-SR10 uses 10 lanes to transmit and another 10 lanes to receive for a total of 20 strands. In data centers and backbones, it may be possible to have 8 or 20 individual strands of fiber. However, those strands may take disparate paths from one end to the other and this can cause delay skew (known as bit skew) resulting in bit errors. For this reason, the 40/100GbE standards are written around fiber optic trunk assemblies that utilize a MPO/MTP multi-fiber array connector. Data is transmitted and received simultaneously on MTP interfaces through 10G simplex transmission over each individual strand of the array cable. In these assemblies, all strands are the same length. Also referred to as "parallel optics", this construction minimizes bit/delay skew, allowing the receive modules to receive each fibers information at virtually the same time.

Copper Transmissions at Higher Speeds

The first 10GbE capable copper interface was developed for the 10GBASE-CX4 application. The physical requirements for this shielded four-lane copper connector is standardized under SFF-8470. As a passive assembly, the SFF-8470/CX4 cables have a reach of 15m. This assembly supports 10GbE, InfiniBand, FibreChannel and FCoE. These assemblies use twinax cable, constructed of two inner conductors with an overall foil covered by a braid shield. Due to their low latency, these cables are popular in supercomputing clusters, High Performance Computing and storage. As part of the 802.3ba 40/100GbE standard, multi-lane 40GBASE-CR4 and 100GBASE-CR10 was defined. This standard specifies the use of 4 and 10-lane twinax assemblies to achieve 40 and 100GbE speeds for distances up to 7m.

40/100G MPO/MTP System

MPO/MTP is available in both 12 and 24 strand termination configurations used at the end of a trunk assembly. A modular laser optimized multimode MPO/MTP system that supports 40G and 100G fiber optic networks includes trunks, harnesses, array cords, modules, and adapter plates. For 40GbE, a 12-fiber cabling solution with each channel featuring four dedicated transmit fibers and four dedicated receiver fibers is used. In general, the middle four fiber remain unused. Parallel transmission is also used for 100GbE with a 24-fiber solution or two 12-fiber solution.

At present, 40GbE is taking over from 10GbE as the new high-growth market segment. Meanwhile, the 40GbE optics are universal in data center and the market of 100GbE is accelerating. Being prepared for 40/100G is essential: within a few short years higher-speed Ethernet will be common in data centers across all types of organizations. Fiberstore is ready. Fiberstore offers various optical communication products to meet diverse demands. For example, we provide 40GBASE-SR4 QSFP+ transceivers, like Finisar FTL410QE2C 40GBASE-SR4 QSFP+ transceiver and Mellanox MC2210411-SR4 40GBASE-SR4 QSFP+ transceiver, which are branded by famous companies and quality guaranteed.

Transceiver Choices for 40 Gigabit Ethernet

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.

CFP Transceiver

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

Fiberstore 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. If you have any demand for the 40GbE components or product solutions, please contact Fiberstore team over sales@fs.com or have a livechat on www.fs.com.

The Basics of Dirrect Attach Cables

Dirrect attach cable (DAC), is a cost effective and proven solution for interconnecting networking applications. It can provide inexpensive and reliable connections using either copper cables or fiber cables. What is DAC? How copper DAC and fiber DAC differ from each other? Here is what you need to know about DACs.

DAC Definition

A direct attach cable is a fixed assembly that is purchased at a given length, with the connector modules permanently terminated to each end of the cable to connect switches to routers or servers. DACs are much cheaper than the regular optics, since the "transceivers" on both ends of DACs are not real optics and their components are without optical lasers. They are preferable choice for their low cost, low power consumption and high performances. DAC are made of the two kinds of cable materials: copper and optical fiber. They are respectively called direct attach copper cable and active optical cable.

DAC Assemblies—Copper

Direct attach copper cable is interchangeable and hot swappable with fiber optic modules. It is designed in either active or passive versions. It supports such multiple protocols as Gigabit & 10G Ethernet, 8G FC, FCoE and InfiniBand. Direct attach copper cable is a cost effective solution over optical transceivers and and cables for short reach applications. It can support higher data rates than traditional copper interfaces—from 4Gbps to 10Gbps per channel. The defect of direct attach copper cable is that it is heavy and bulky, making it difficult to be managed. Furthermore, due to the nature of electrical signals, direct attach copper cable is vulnerable to the effects of electromagnetic interference (EMI), such as undesirable responses, degradation, or complete system failure. Fiberstore offers various QSFP+ direct attach copper cables with different lengths for your 40G applications. For example, lengths of Juniper EX-QSFP-40GE-DAC-50CM, QFX-QSFP-DAC-1M and QFX-QSFP-DAC-3M compatible QSFP+ to QSFP+ passive copper cables are respectively 0.5m, 1m, and 3m.

DAC Assemblies—Fiber

Active optical cable (AOC) is an alternative to optical transceivers, eliminating the separable interface between transceiver module and optical cable. It meets Small Form-factor (SFF) standards. Compaired to direct attach copper cable, AOC weighs less and can support longer transmission distance. It is immune to electromagnetic energy since the optical fiber is dielectric (not able to conduct electric current). What’s more, it is an alternative to optical transceivers and it can eliminate the separable interface between transceiver module and optical cable. AOC has no EMI. However, it costs more than copper cable.

Applications of DAC

Direct attach cables are widely applied in storage area network, data center, and high-performance computing connectivity. They suppoet high speed I/O applications in storage, networking and telecom markets. And they can also be sused in witches, servers, routers, network interface cards (NICs), and Host Bus Adapters (HBAs). There are many different kinds of DACs, they all have their specific applicayions. For example, 40G AOC is commonly used for short-range multi-lane data communication and interconnect applications.

Conclusion

Fiberstore offers a variety of high speed interconnect DAC assemblies including 10G SFP+ cables, 40G QSFP+ cables, and 120G CXP cables to satisfy the demands from 10G to 100G interconnection. Direct attach cables provided by Fiberstore can be customized to meet different requirements. And we also offer all kinds of high quality QSFP+ modules branded by many famous companies, like Brocade QSFP+, Dell QSFP+, Juniper QSFP+, Finisar QSFP+, Intel QSFP+, etc. You can buy from us with confidence.

Cisco 40GBASE QSFP+ Modules

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.

Fiberstore 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 Fiberstore 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.

What Makes 40G Active Optical Cable So Popular?

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. Fiberstore 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.

Cabling Connectivity Options for 40Gbps Infrastructure

Driven by growing bandwidth and network performance demand, data center network infrastructure is witnessing a transformation. The speed of data center now is increasing to 40 Gbps. Thus, new cabling infrastructure and cabling connectivity options are required. Here some commonly used cabling connectivity options for 40Gbps infrastructure will be introduced in this post.

Pluggable Modules: 40G QSFP+ Transceivers

Fiber optic transceiver is an electronic device that receives an electrical signal, converts it into a light signal, and launches the signal into a fiber. It also receives the light signal, from another transceiver, and converts it into an electrical signal. It is the key component in fiber optic transmission. The basic interface of 40G pluggable optical modules are 40GBASE-LR4 and 40GBASE-SR4 QSFP+ form factor.

40GBASE-LR4 QSFP+: 40GBASE-LR4 transceiver support with a link length up to 10 km over 1310nm single-mode fiber. It is most commonly deployed between data centers or IXP sites. The image below shows a Cisco QSFP-40G-LR4 compatible 40GBASE-LR4 QSFP+ transceiver.

40GBASE-SR4 QSFP+: 40GBASE-SR4 transceivers are used in data centers to interconnect two Ethernet switches with 8 fiber parallel multimode fiber OM3/OM4 cables. It can support transmission distance up to 100 m with OM3 fiber and 150 m with OM4 fiber. The optical interface of 40GBASE-SR4 QSFP+ is MPO/MTP. The image below shows a Cisco QSFP-40G-SR4 compatible 40GBASE-SR4 QSFP+ transceiver.

In addition, for single-mode fiber transmission, there are 40GBASE-LR4 Parallel Single Mode (PSM) transceivers which are used to provide support for up to four 10Gbps Ethernet connections on a QSFP+ port over single mode fiber at distances up to 10 km. For multimode fiber transmission, QSFP+ extended SR4 transceivers are developed which is designed with optimized VCSEL with better performance of RMS spectral width compared with QSFP+ SR4. QSFP+ extended SR4 transceivers can support transmission distance up to 300 m with OM3 fiber and 400 m with OM4.

Passive & Active Direct Attach Copper Cables

The QSFP+ passive or active direct attach copper cables are designed with twinax copper cable and terminated with QSFP+ connectors. The main difference between passive QSFP+ DAC and active QSFP+ DAC is that the passive one is without the active component. They provide short distance inexpensive connectivity at up to 40Gbps rates and operate 4 independent 10G channels using the QSFP connector footprint. Each of the four channels can operate at multi-rate speeds Gigabit to 10Gbps. The image below shows QSFP-4SFP10G-CU1M compatible QSFP+ to 4SFP+ passive breakout copper cable.

Active Optical Cable (AOC) Assemblies

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 is a high performance integrated cable 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. And hot-pluggable transceiver allows insertion and removal of devices without powering down the system. The image below shows QSFP-4X10G-AOC10M compatible QSFP+ to 4SFP+ active optical breakout cable.

Fiberstore offers a comprehensive solution for 40G fiber optic cabling connectivity. We support a full range of both copper cables and optical transceivers for 40GbE, compliant to the IEEE standards. For copper both QSFP+ to QSFP+ (40G to 40G) and QSFP+ to SFP+ (40G to 4x10G) cables enable short reach options. For longer distances Fiberstore offers a wide range of optical transceivers for various fiber types and reach requirements.

Upgrading to 40/100 Gigabit Ethernet

To support the changing and fast-growing bandwidth demands of data centers (DCs), the IEEE ratified standards for supporting 40 Gigabit Ethernet (40GE) and 100 Gigabit Ethernet (100GE), known as IEEE 802.3ba. 40GE and 100 GE belong to a family of network technologies that primarily are used in local area networks. As they are becoming more and more popular, it is very necessary to know more about them. This post offers a quick-reference guide to increase your familiarity with issues in the migration to 40 and 100GE systems.

Cabling Systems

Both 40 and 100 Gigabit Ethernet can be deployed using the same cabling systems in use today. Multi-mode will employ parallel optics using MPO interconnects and require additional cable infrastructure depending on the system deployed while single mode fiber will employ serial transmission and use LC or SC connectors. The approach used for the higher speed data rates is based on advanced transceiver technologies engineered to take advantage of the full bandwidth of laser optimized fibers. Both single mode fiber (SMF) and multi-mode fiber (OM3, OM4) were approved in the standard.

Standards

• 40GBase-SR4: multimode fiber with four fiber pairs (OM3/OM4)
• 40GBase-LR4: single-mode fiber pairs with 4 wavelengths a 10Gbit/s at 10 km
• 40GBase-KR4: short distances in the backplane (4 pairs of wires)
• 40GBase-CR4: twinax cable with 4 pairs
• 100GBase-CR10: twinax cable with 10 pairs
• 100GBase-SR10: multimode fiber with 10 fiber pairs (OM3/OM4)
• 100GBase-SR10: single-mode fiber pairs with 4 wavelengths a 25Gbit/s at 10 km
• 100GBase-ER4: single-mode fiber pairs with 4 wavelengths a 25Gbit/s at 40 km

Module Types

QSFP: The QSFP (quad small-form-factor pluggable) is the primary way of delivering 40GE and are now appearing in 100GbE-capable form. These present either MPO connectors for multi-mode optics or LC connectors for single-mode optics. It is similar in size to the CXP and provides four transmit and four receive lanes to support 40GbE applications. QSFP+ (quad small form-factor pluggable plus), as the updated version of QSFP, is a new multi-source agreement (MSA) for high speed application. QSFP+ gradually replace QSFP and is widely used by people as it can provide higher bandwidth. The following picture shows an Avaya AA1404001-E6 compatible QSFP+ transceiver.

CFP: The CFP (C form-factor pluggable) transceiver features twelve transmit and twelve receive 10Gb/s lanes to support one 100GbE port, or up to three 40GbE ports. CFP form factor optics are available in 40GbE and 100GbE varieties. Its larger size is suitable for the needs of single-mode optics and can easily serve multi-mode optics or copper as well. These present MPO connectors for multi-mode optics or SC connectors for single-mode optics. CFP modules use the 10-lane CAUI-10 electrical interface.

CFP2: The CFP2 is an evolution of the existing CFP form factor, using manufacturing and optics advances to reduce the size of the module to approximately half that of the original CFP, allowing for higher interface density. CFP2 modules use the 10-lane CAUI-10 electrical interface or the 4-lane CAUI-4 electrical interface.

Requirements and Objectives

40GE and 100GE fulfill the following requirements and objectives:

• Preserve existing 802.3 frame format, minimum size, and maximum size.
• Support high-speed switching, routing, and application functions in data centers.
• Exhibit a bit error rate (BER) of 10-12 or better.
• Provide support for optical transport network (OTN).
• Provide specifications for operation over single-mode optical fiber, laser optimized multimode optical fiber, copper cables, and backplanes.
• Support high-bandwidth applications such as video on demand (VoD) and high-performance computing (HPC).

The throughput and reliability of a 40/100 Gigabit Ethernet installation is directly related to the cabling, the choice of connectivity, and proper installation. Fiberstore's superior cable and connectivity designs provides you with superior levels of performance and operation. We offer all kinds of cables and transceiver modules for your applications, such as Dell Force10 GP-QSFP-40GE-1SR 40GBASE-SR4 QSFP+ transceiver, or Juniper QFX-QSFP-DAC-3M compatible QSFP+ to QSFP+ passive copper cable, and so on. You can buy from us with confidence.

1000BASE-What?

There are many kinds of optical transceiver in the market. When looking at a transceiver module, you may see words like 1000BASE-CX, 1000BASE-SX, 1000BASE-T, and so on. For example, the following picture shows a 3CSFP91 compatible SFP transceiver. You can see "1000BASE-SX SFP" on it. What do they mean? And what's the difference between 1000BASE-SX, 1000BASE-CX, and 1000BASE-T? In this post, a brief introduction to 1000BASE will be given.

What Does 1000BASE Mean?

The "1000" refers to the transmission speed of 1000Mbps. In computer networking, Gigabit Ethernet (GE or 1GbE) is a term describing various technologies for transmitting Ethernet frames at a rate of a gigabit per second, as defined by the IEEE 802.3-2008 standard. The cables and equipment are very similar to previous standards and have been very common and economical since 2010. You may wonder what the word "BASE" means. BASE refers to "baseband", meaning that this is an unfiltered line not requiring a digital modulation scheme. Back in the day, there was a 10PASS-TS version of Ethernet that used a signaling scheme similar to a modem, but baseband is dominant today. So 1000BASE refers to a Gigabit Ethernet connection that uses the unfiltered cable for transmission.

1000BASE-What?

The next part is the cabling used to carry the signals. The earliest forms of Ethernet used coaxial cable, but thin twisted-pair cabling became popular in the mid-1990s. Faster versions of Ethernet also often use fiber optics rather than electrical signals. There are a bewildering assortment of physical interconnects for Ethernet. But the naming system isn't as complex as it might appear. The first letter tells us which kind of wire we are talking about:

• "S" means short-range multi-mode optical cable (less than 100 m)
• "L" means long-range single- or multi-mode optical cable (100 m to 10 km)
• "E" means extended-range optical cable (10 km to 40 km)
• "Z" means long-range single-mode cable at a higher wavelength
• "T" means twisted-pair cable (e.g. the common Category 5 in use today)
• "K" means a copper backplane
• "C" means balanced copper cable
• "B" uses two wavelengths over a single optical cable

Next is the coding scheme for data on the wire: "X" means 8B/10B block coding for Gigabit Ethernet. Then, we have a number representing the number of parallel "lanes" for data: "1" would mean serial (non-parallel) but is omitted instead; "4" or "10" are available for copper wire; just about any other number could be used for optical lanes or wavelengths. As you can see, common unshielded twisted pair wiring is "BASE-T", optics are denoted according to their range ("S", "L", "E"), and backplanes use "K" copper.

Examples

1000BASE-SX standard is a variant coupled to a VCSEL laser with a short wavelength of 850nm. It has a maximum length of 550 meters. 1000BASE-SX technologies are being widely implemented in enterprise-level networks and primarily used between pieces of equipment within a building. 1000BASE-LX standard has a working distance of up to 5 km over single-mode optic fiber. And it can also be used to transmit data over common multi-mode fiber options with a maximum length of 550m. 1000BASE-EX standard is capable of transmitting up to 40 km over a single-mode optic fiber pair due to higher quality optics. 1000BASE-CX is an initial standard for Gigabit Ethernet connections with maximum distances of 25 meters using balanced shielded twisted pair. 1000BASE-KX standard is for Ethernet operation over electrical backplanes. It defines one to four lanes of backplane links, one RX and one TX differential pair per lane. The 1000BASE-KX variant uses 1.25GBd electrical (not optical) signalling speed. 1000BASE-T normally uses four pairs of the commonly installed Category 5 unshielded twisted pair (UTP) cable or enhanced category 5 cabling version of UTP cabling to achieve gigabit data rates. The image below shows a Moxa SFP-1GLSXLC 1000BASE-LX SFP transceiver.

There are various 1000BASE SFP transceivers available depending on the your application and distance capability required. Fiberstore is a professional manufacturer and supplier, offering various kinds of 1000BASE SFP transceivers 100% compatible with major brands like Cisco, HP, Juniper, Force10, D-link, 3Com. They are backed by a lifetime warranty, and we also can customize optical transceivers to fit your specific requirements.