Category Archives: Fiber Optical Transceivers

Getting to Know About DWDM Tunable Transceiver

DWDM (Dense Wavelength Division Multiplexing) technology offers a great way to boost channel capacity and transmission speed for optical systems. And it has been used in many applications, especially in long haul transmissions. In these applications, DWDM optic transceiver plays an important role. This post intends to introduce a special kind of DWDM transceiver—DWDM tunable transceiver.

What Is a DWDM Tunable Transceiver?

DWDM tunable transceiver is a unique transceiver that can select the channel or “color” the laser emits. Put it in simple terms, most WDM systems generally use optical transceivers with a fixed wavelength. That means there is a spare for each wavelength in use. But tunable transceiver has the capacity to adjust the wavelength of the transceiver on-site to meet different requirements. That’s the most distinguished point of tunable transceivers. Another characteristic of tunable transceivers is that the tunable function only lies in DWDM system due to the dense wavelength grid of DWDM.

Typically the tunable transceivers are for the C-band 50GHz. Around 88 different channels can be set with intervals of 0.4nm, which is the 50GHz band. These optics usually start from channel 16 up to 61 but this depends on the manufacturer’s router/switch and which channels it supports. And the transmission distance of DWDM tunable transceiver over single mode fiber is up to 80km and data speed is up to 10Gbps.

In addition, the DWDM tunable transceivers are available for a wide range of equipment like routers, switches and servers. With these transceivers, network operators can change wavelengths unlimited within the C-band DWDM ITU grid.

Types of DWDM Tunable Transceiver

In today’s market, there are mainly two kinds of DWDM tunable transceivers.

DWDM Tunable XFP transceiver

Tunable XFP transceiver are manufactured with an integrated full C-band tunable transmitter and a high performance receiver. Wavelengths can be set as default in 50GH DWDM ITU grid. The maximum distance of this transceiver on a single mode fiber is up to 80km. In the market, different manufactures may name tunable XFP transceiver in different forms. For example, Cisco may name it as “ONS-XC-10G-C” while Juniper version is “XFP-10G-CBAND-T50-ZR”. Besides, this transceiver be tuned in different ways.

10g dwdm tunable xfp transceiver

DWDM Tunable SFP+ Transceiver

As one kind of DWDM SFP+ module, the tunable SFP+ optical transceiver is a full duplex serial electric, serial optical device. Its transmit and receive functions are contained in a single module that provides a high-speed serial link at 9.95 to 11.3Gbps signaling rates. And the transceiver supports the enhanced SFP+ specification. Here is a simple picture showing its working process.

SFP plus tunable transceiver

On the transmit side, the serial data are passed from the electrical connector to a modulator driver. The modulator driver modulates a C-band cooled tunable transmitter, enabling data transmission over up to 80km on single mode fiber through an industry standard LC connector. On the receive side, the 10G optical data stream is recovered from an APD through a transimpedance amplifier to the electrical connector.

Benefits of DWDM Tunable Transceiver

Tunable transceivers have progressed rapidly in recent years. They have become popular in DWDM transmission systems because of their multi-faceted abilities and ease of spare use. Especially when combined with ROADM (reconfigurable optical add-drop multiplexers), DWDM tunable transceivers become a powerful transmission component. In simple terms, DWDM tunable transceivers have benefits below.

  • A wide tuning range. Compared with common fixed wavelength optical transceivers, DWDM tunable transceivers can save time and money in the long run.
  • Be more suitable for 100G systems by reducing line-width. The ability to adjust wavelengths provides more convenience to fit different transmitting needs.
  • Tunable lasers are capable of switching wavelengths in just nanoseconds. Tunable laser is a vital part of tunable transceivers. It is a high-speed and high-performance optics, enabling the needed wavelength to be reprogrammed in seconds.
Summary

DWDM tunable transceivers are able to function on various wavelengths and to adjust wavelengths according to users’ needs, making them prevalent among DWDM systems. This article mainly introduces the basis and two types of DWDM tunable transceivers. If you want to know more about it, please visit FS.COM.

Related Articles:

Wavelength Switching Solution: Tunable XFP Transceiver

Why Use Tunable DWDM SFP+ Transceivers?

DWDM Tunable SFP+ VS. DWDM Fixed Wavelength SFP+ Transceiver

Things You Need to Know About DWDM Transceiver

In optical communications, DWDM (Dense Wavelength Division Multiplexing) technology enables a number of different wavelengths to be transmitted on a single fiber, which makes it a popular choice among many different areas such as local area networks (LANs), long-haul backbone networks and residential access networks. In these transmission processes, DWDM transceivers play an important role. Here is a brief introduction to them.

Basics of DWDM Transceiver

DWDM transceiver, as its name shows, is a kind of fiber optic transceiver based on DWDM technology. As mentioned above, it enables different wavelengths to multiplex several optical signals on a single fiber without requiring any power to operate. And these transceivers are designed for high-capacity and long-distance transmissions, supporting to 10 Gbps and spanning a distance up to 120 km. Meanwhile, the DWDM transceivers are designed to Multi-Source Agreement (MSA) standards in order to ensure broad network equipment compatibility.

The basic function of DWDM transceiver is to convert the electrical signal to optical and then to electrical signal, which is as same as other optical transceivers. However, based on DWDM technology, DWDM transceiver has its own features and functions. It’s intended for single-mode fiber and operate at a nominal DWDM wavelength from 1528.38 to 1563.86 nm (Channel 17 to Channel 61) as specified by the ITU-T. And it is widely deployed in the DWDM networking equipment in metropolitan access and core networks.

Common Types of DWDM Transceiver

There are different types of DWDM transceiver according to different packages such as DWDM SFP transceiver, DWDM SFP+ transceiver, DWDM XFP transceiver, DWDM XENPAK transceiver and DWDM X2 transceiver. Here is a simple introduction to them.

DWDM SFP Transceiver

DWDM SFP transceiver is based on the SFP form factor which is an MSA standard build. This transceiver provides a signal rate range from 100 Mbps to 2.5 Gbps. Besides, DWDM SFP transceiver meets the requirements of the IEE802.3 Gigabit Ethernet standard and ANSI fibre channel specifications, and are suitable for interconnections in Gigabit Ethernet and fibre channel environments.

dwdm-sfp

DWDM SFP+ Transceiver

DWDM SFP+ transceiver, based on the SFP form factor, is designed for carriers and large enterprises that require a flexible and cost-effective system for multiplexing and transporting high-speed data, storage, voice and video applications. The maximum speed of this transceiver is 11.25G. It’s known to all that DWDM enables service providers to accommodate hundreds of aggregated services of sub-rate protocol without installing additional dark fiber. Therefore, DWDM SFP+ transceiver is a good choice for 10G highest bandwidth application.

dwdm-sfp-plus

DWDM X2 Transceiver

DWDM X2 Transceiver is a high performance serial optical transponder module for high-speed 10G data transmission applications. The module is fully compliant to IEEE 802.3ae standard for Ethernet, which makes it ideally suitable for 10G rack-to-rack applications.

dwdm-x2

DWDM XFP Transceiver

DWDM XFP transceiver is based on the XFP form factor which is also an MSA standard build. The maximum speed of this transceiver is 11.25G and it is usually used in 10G Ethernet. This transceiver emits a specific light. And there are different industry standards and the 100Ghz C-band is the most used one which has a spacing of 0.8 nm. What’s more, DWDM XFP supports SONET/SDH, 10GbE and 10 Gigabit fibre channel applications.

dwdm-xfp

DWDM XENPAK Transceiver

DWDM XENPAK transceiver is SC duplex receptacle module and is designed for backbone Ethernet transmission systems. It is the first 10GbE transceiver ever to support DWDM. And it can support 32 different channels for transmission distance up to 200 km with the aid of EDFAs. DWDM XENPAK transceiver allows enterprise companies and service providers to provide scalable and easy-to-deploy 10 Gigabit Ethernet services in their networks.

dwdm-xenpak

Applications of DWDM Transceiver

As the growing demand of bandwidth, DWDM technology is becoming more and more popular. And DWDM transceivers are commonly used in MANs (metropolitan area networks) and LANs. Different types of DWDM transceiver have different applications. For example, DWDM SFP transceivers are applied in amplified DWDM networks, Fibre Channel, fast Ethernet, Gigabit Ethernet and other optical transmission systems, while DWDM XFP transceivers are usually used in the fields which meet the 10GBASE-ER/EW Ethernet, 1200-SM-LL-L 10G Fibre Channel, SONET OC-192 IR-2, SDH STM S-64.2b, SONET OC-192 IR-3, SDH STM S-64.3b and ITU-T G.709 standards.

Conclusion

In summary, DWDM transceiver is an essential component in DWDM systems. Fiberstore offers various DWDM transceivers and is able to provide the advanced technology and strong innovative capability to produce the best optical components for DWDM systems. If you are interested in our products, please visit FS.COM for more detailed information.

Suggestions for Solving Unsupported Transceiver Errors

The unsupported transceiver errors may arise at any time of your work. Though this situation is the least you want to see during work, you must be enough prepared to solve issues in time. To deal with the errors is now an essential part to keep good running of devices. And different vendors will have tips to solve errors for their own products. But are there any suggestions for general issues? The answer is yes. This article will give some advice for how to deal with unsupported transceiver errors on ordinary occasions.

Unsupported-Transceiver-Errors

Suggestions

1)Check the error message first before actually deal with the problem. Different ways to address the errors are depending on the message you receive. Here is an example, when you receive this message, “3750e-sw1(config)#service unsupported-transceiver [1]”, the error may result from the false customer installation or a defective product. Thus, error message is a good source to decide your next step.

2)An uncertified transceiver will cause errors under most cases. When the third-party device does not come from a channel partner, problems may also arise. It is not that easy to address router issues if the transceivers is required to be made from the same manufacturer. But specialists may turn to hack codes to solve the problem.

3)Hidden commands of some devices may also cause errors. The message will go like “service unsupported transceiver”. But it allows other transceivers as an option for you to decide whether the transceiver should be replaced.

4)Before removing the transceiver to solve a third-party error, you can look up other options first. Because sometimes the third-party transceiver can provide significant savings for you. Perhaps one of the savings will help settle the problem.

About Third-Party Transceivers

Although you may encounter the unsupported errors when using the third-party transceiver, it still has some advantages. The major benefit is the cost which is much lower than the cost of original transceivers. Since the cost of transceiver takes a huge part of the entire system cost, reducing the investment on transceiver can greatly save expenses for better designs.

Also, the compatibility of third-party transceivers has been greatly increased thanks to the fully specified international standards. The risk of incompatibility is much lower, and there is no need to worry about buying a transceiver from formal vendors. For instance, FS.COM is one of the reliable manufacturers that provides cost-effective third-party transceivers, and all of the transceivers are 100% compatible to any named brands like Cisco, Juniper, Arista and so on.

Conclusion

Anyway, in order to avoid unsuspected transceiver errors, the fundamental aim is to make sure that the transceiver completely complies with IEEE and MSA standards. Understanding the hidden commands can also help you find out the source of error. So long as you follow the above suggestions, most of the problems can be solved in a short time. The purpose of dealing with the errors is all about getting good results, and your working efficiency will also be improved if there is no problem with the devices.

Active Optical Cable (AOC Cable) Overview

In respond to the demand for a higher data bandwidth, active optical cable (AOC cable) has came into being to satisfy different cloud computing applications. Active optical cable is a term used to describe a cable that mates with standard electrical interfaces. The electrical-to-optical conversion on the cable ends is adopted to enhance the transmission speed and distance of the cable without sacrificing compatibility of standard electrical interfaces. This article will give a general introduction of active optical cable (AOC) and its most popular product in the current market.

Structure of Active Optical Cable (AOC)

AOC cable mainly consists of two parts- the fiber optic connector and fiber cable. The connection between fiber cable and connectors is not separable. If the connector or cable needs to be changed, they should be removed together. The electrical and optical signal conversion can be achieved right through each ends of optical fiber.

active optical cable (AOC cable)

Advantages of Active Optical Cable (AOC)

However, people may wonder the reasons why choosing active optical cable over direct attach copper cable. Here are some advantages of using active optical cable:

1) Although both cables are used for short range data communication, active optical cable is able to provide a longer reach than direct attach copper cable among devices.

2) Active optical cable has a higher bandwidth because its signal transmits through optical fiber as optical signal which transmits faster than electrical signal in copper cable. The maximum throughput of AOC cable is up to 40 Gbps with QSFP+.

3) The weight of active optical cable is lighter than copper cable due to the optical fiber material. It is possible for AOC cable to achieve a simpler cable management with a lower weight.

4) EMI (electromagnetic interference) immunity is another benefit of active optical fiber. EMI is a disturbance generated by an external source that affects an electrical circuit by electromagnetic induction, electrostatic coupling or conduction. Since the optical fiber is a kind of dielectric which is unable to conduct electric current, active optical cable will not be affected by the electromagnetic energy.

Applications of Active Optical Cable (AOC)

Active optical cable has been applied to different fields. The followings are the most typical applications for AOC cable:

1) Infiniband QDR, DDR and SDR interconnects

2) Data aggregation, backplane and proprietary density applications

3) PCI-Express, SAS/SATA, Fiber Channel compatible interconnect

4) 40GBE and 10GBE interconnects

5) 10G, 40G telecom connections

6) Hubs, switches, routers, servers

7) Ethernet 10G, 40G

8) Data centers

9) High performance computing clusters

Popularity of 40G Active Optical Cable

Nowadays 40G QSFP+ active optical cable has become one of the most popular products in the market. It is an active optical cable used for 40 GbE terminated with 40GBASE QSFP+. Particularly, 40G breakout active optical cables, such as 40GBASE QSFP+ to 4xSFP+ AOC or 40GBASE QSFP+ to 8xLC AOC, are cost-effective solutions for 40G to 10G migration.

Conclusion

Active optical cable market accounts for a great share and is still booming for further development. The interconnection in short range and high speed between devices makes active optical cables practical in data center. As the technology matures, the application of active optical cable will be migrated to higher speed transmission in the future.

Who is the Winner of 10G Transceiver?

10G transceiver refers to optical module which can transmit and receive the data signal of 10 gigabits per second. Typically, the fiber optic transceivers including 10G XENPAK, X2, XFP and SFP+ (small form-factor pluggable plus) are widely used for 10 Gigabit Ethernet. But who is the winner among these transceivers? From the following introduction we may find some clues.

XENPAK Transceivers

As the first published form-factor 10G transceiver, the XENPAK, was by far the largest in physical size. This standard was driven primarily by large systems vendors and was intended to support essentially any optical application a system vendor may want to deploy. At the time this multi-source agreement (MSA) was published, 10Gbps optical interfaces supporting transmission distances of 80km or more were of a size and heat dissipation that required a relatively large (by today’s standards) package size.

10g transceiver XENPAK-Transceivers

X2 and XFP Transceivers

Many in the industry recognized the size of the XENPAK as very limiting factor and began working on alternative standards. Over the following two years three alternative MSAs were published, called: X2 and XFP. When these standards were written they were intended to enable optical interfaces supporting up to about 10 km. The X2 and XFP form-factors both saw considerable deployment. As optical technology has advanced over the last ten years, X2 and XFP modules have been developed that support all of the high-power, long-distance applications once reserved to the larger XENPAK transceivers.

X2-and-XFP-transceivers

SFP+ Transceivers

Five years after the first 10Gbps optical transceiver standard was issued, a new MSA was published called the “SFP+”. This agreement has been the basis for the most commercially successful 10Gbps optical transceivers by a large margin.

There are several reasons for the success of the SFP+ standard:

  • Flexibility The SFP+ standard builds on a previous one, the SFP MSA (primarily a 1Gbps standard). SFP+ modules are the same physical size as SFPs and the SFP+ standard allows for either type of module to operate in the new SFP+ slots.
  • Small Size SFP+ modules are one tenth the size of the original XENPAK 10G modules and are the same size as the popular 1Gbps SFP modules. This small size allows the design of systems with 10G ports of the same density as previous generations with 1G ports.
  • Low Cost Since SFP+ modules share many components (bezel, housing, latch/locking mechanism) on the previous SFP standard, the cost of the new 10G modules inherits the low cost of these components. SFP+ units are also lower power, contributing to cost savings

10g transceiver

However, do you really know how to choose the right 10G form-factor? The following aspects should be taken into consideration:

Cost

When considering new or used equipment for a new network build or expansion, attention should definitely be given to the type of 10G ports in that equipment. One important reason is capital costs. Older gear offering XFP, X2 or XENPAK ports may be attractive due to what seems like very low prices. However, the cost of equivalent 10G optics in those older form factors is twice to three times the price of SFP+ based modules. Therefore, when the cost of the optics are included, total system costs may end up higher.

Power

The older XFP, X2 and especially XENPAK gear, both the host system and the 10GBase optical modules, consume considerably more power than the new SFP+ modules. Power costs include capital outlays for larger power/battery plant as well as operational cost of the electrical power itself.

Rack Space

Depending on the location, space in equipment racks can be quite expensive. Equipment utilizing the older 10Gbase interfaces is almost always substantially less dense, consuming more rack space per 10G interface available.

Who is the Winner of 10G Transceiver?

From the above, there is no doubt that SFP+ wins the battle. In consideration of the advantages in cost, size, power and flexibility of supportable optical interfaces, SFP+ is preferred among the 10G transceivers. So far, there has not been any new standard for 10G network due to a higher speed demand of Ethernet. Thus, SFP+ transceivers will remain to dominate the 10G transceiver market.

Fiberstore’s 10 Gigabit Ethernet Transceivers and Cables Frequently Asked Questions

What is the difference between SFP+ and SFP?

The pinouts of SFP and SFP+ connectors are identical. However, SFP has a maximum data rate of 5Gb/s whereas SFP+ is designed for 10Gb/s. The SFP receptacles and plugs are not as well impedance matched as SFP+ receptacles and plugs. Also SFP+ cable is designed for 10Gb/s whereas SFP cable may not be able to satisfactorily transmit that rate.

What is the distance supported by the SFP+ SR transceiver?

The supported distance is up to 300 meters depending on the quality of the multimode fiber (MMF) you use. Quality of MMF is listed as OM1 (up to 33 meters), OM2 (up to 82 meters), OM3 (up to 300 meters), and OM4 (up to 400 meters). Check with the supplier for the cable distance supported. Take GP-10GSFP-1S as an example, it is Dell Force10 10GBASE-SR SFP+ covering a distance of 300m over OM3 multimode cable.

Can I use SFP+ cables in SFP ports?

Yes, SFP+ cables are compatible to SFP ports and will work fine. SFP cables are not compatible to SFP+ ports. SFP+ receptacles have a mechanical feature to prevent engaging SFP plugs.

Do Fiberstore’s SFP+ direct-attach Twinx passive cables work with Cisco or other third-party switches?

Fiberstore’s direct-attach SFP+ Twinx passive cables are fully compatible with the original brand like Cisco. For example, SFP-H10GB-CU3M is Cisco SFP+ to SFP+ passive copper cable from Fiberstore which is fully compatible with Cisco switch. The following image shows that our professional trained staff tests the compatibility and interoperability of each optics to make sure our customers to receiver the optics with superior quality.

Fiberstore test program

What are the distances supported by cables to use with the 10GBase-T ports? Does Fiberstore offer these cables?

Data centers have a large installed base of Cat 5/6/7 twisted pair cables for the last decades—initially for 1000BASE-T and now for use with 1/10GBase-T infrastructure. Fiberstore does offer these cables since they are industry standard and widely available from us in various lengths and colors. Distances supported at 10 Gbps speed:

  • CAT 6A and CAT 7 cables supporting 100 meters
  • CAT 5e and CAT 6 cables supporting 55 meters

Do the SFP+ optical transceivers support 1 GbE operation?

Yes, they support 1GbE and 10 GbE dual rates and can be configured for 1 GbE.

Will the SFP+ optical transceivers auto-negotiate between 1 GbE and 10 GbE?

Auto-negotiation is not supported between the 10 GE and 1 GE speed. The transceiver must be manually configured to operate at 1 GE speed.

How do I use the SFP+ ports for 1000BASE-T?

You need to purchase Fiberstore’s SFP+ to 1000BASE-T Media Converter. (SFP+/Copper RJ45), part number FMC-1SFP/1RJ45-GB.

Is TwinX same as Twinax?

Yes.

Does the Twinx copper cable plug directly into the NIC and the switch?

Yes, the copper cable has an SFP+ or QSFP connector on both ends of the cable that directly plugs into the corresponding ports of the switch and NIC.

Should I use optical transceivers with the SFP+ and QSFP direct-attach Twinx copper cables?

No. These are direct-attach Twinx cables and come with connectors that plug directly into the SFP+ port or the QSFP port of the switch/NIC on either end. Transceiver cannot be used.

What is the advantage of SFP+ Twinx copper cable?

It is a low-cost option for shorter distances up to 5 meters.

Is 10GBase-T same as 10GBASE-T?

Yes. 1GBase-T is shorthand for 1000BASE-T and 10GBase-T is same as 10GBASE-T; they are the twisted pair implementations of 1 GbE and 10 GbE respectively.

What are the SFP+ copper cables provided by Fiberstore?

10G SFP+ copper cable

The above chart lists detailed information about some of the 10G SFP+ cables from Fiberstore. We also offer SFP+ copper cables that are fully compatible with major brand like Cisco, Juniper, Brocade, etc. The supported distance of this cable varies from 0.5m to 7m. Users can connect our SFP+ copper cable with top-of-rack (ToR) switch to realize 10G connectivity. For more information, please contact us directly.

The Basics of 1000BASE-SX and 1000BASE-LX SFP

Gigabit Ethernet has been regarded as a huge breakthrough of telecom industry by offering speeds of up to 100Mbps. Gigabit Ethernet is a standard for transmitting Ethernet frames at a rate of a gigabit per second. There are five physical layer standards for Gigabit Ethernet using optical fiber (1000BASE-X), twisted pair cable (1000BASE-T), or shielded balanced copper cable (1000BASE-CX). 1000BASE-LX SFP and 1000BASE-SX SFP are two common types of optical transceiver modules in the market. Today’s topic will be a brief introduction to 1000BASE-LX and 1000BASE-SX SFP transceivers.

1000BASE in these terms refers to a Gigabit Ethernet connection that uses the unfiltered cable for transmission. “X” means 4B/5B block coding for Fast Ethernet or 8B/10B block coding for Gigabit Ethernet. “L” means long-range single- or multi-mode optical cable (100 m to 10 km). “S” means short-range multi-mode optical cable (less than 100 m).

1000BASE-SX
1000BASE-SX is a fiber optic Gigabit Ethernet standard for operation over multi-mode fiber using a 770 to 860 nanometer, near infrared (NIR) light wavelength. The standard specifies a distance capability between 220 meters and 550 meters. In practice, with good quality fiber, optics, and terminations, 1000BASE-SX will usually work over significantly longer distances. This standard is highly popular for intra-building links in large office buildings, co-location facilities and carrier neutral internet exchanges. 1000BASE-SX SFP transceiver works at 850nm wavelength and used only for the purposed of the multimode optical fiber with an LC connector. 1000BASE-SX SFP traditional 50 microns of multimode optical fiber link is 550 meters high and 62.5 micron fiber distributed data interface (FDDI) multimode optical fiber is up to 220 meters. Take EX-SFP-1GE-SX as an example, this SX fiber transceiver supports DOM function and the maximum distance of the SX SFP is 550 m. The 1000Base-SX standard supports the multimode fiber distances shown in table 1.

1000Base-SX standard

1000BASE-LX
Specified in IEEE 802.3 Clause 38, 1000BASE-LX is a type of standard for implementing Gigabit Ethernet networks. The “LX” in 1000BASE-LX stands for long wavelength, indicating that this version of Gigabit Ethernet is intended for use with long-wavelength transmissions (1270–1355 nm) over long cable runs of fiber optic cabling. 1000BASE-LX can run over both single mode fiber and multimode fiber with a distance of up to 5 km and 550 m, respectively. For link distances greater than 300 m, the use of a special launch conditioning patch cord may be required. 1000BASE-LX SFP is intended mainly for connecting high-speed hubs, Ethernet switches, and routers together in different wiring closets or buildings using long cabling runs, and developed to support longer-length multimode building fiber backbones and single-mode campus backbones. E1MG-LX-OM is Brocade 1000BASE-LX SFP, this LX single-mode transceiver operates over a wavelength of 1310nm for 10 km.

1000BASE-LX-SFP

Difference Between LX, LH and LX/LH
Many vendors use both LH and LX/LH for certain SFP modules, this SFP type is similar with the other SFPs in basic working principle and size. However, LH and LX/LH aren’t a Gigabit Ethernet standard and are compatible with 1000BASE-LX standard. 1000BASE-LH SFP operates a distance up to 70km over single-mode fiber. For example, Cisco MGBLH1 1000BASE-LH SFP covers a link length of 40km that make itself perfect for long-reach application. 1000BASE-LX/LH SFP can operate on standard single-mode fiber-optic link spans of up to 10 km and up to 550 m on any multimode fibers. In addition, when used over legacy multimode fiber type, the transmitter should be coupled through a mode conditioning patch cable.

Conclusion
1000BASE-LX SFP and 1000BASE-SX SFP are the most commonly used components for Gigabit Ethernet application. With so many types available in the market, careful notice should be given to the range of differences, both in distance and price of multimode and single-mode fiber optics. FS.COM offers a large amount of in-stock 1000BASE SFP transceivers which are compatible for Cisco, Juniper, Dell, Finisar, Brocade, or Netgear in various options. If you have any requirement of our products, please send your request to us.

Related Article: How to Solve the Problems When Using SFP Optical Transceiver
A Quick Overview of Cisco 1000BASE-T GLC-T SFP Copper Module

Introduction to 10G SFP+ Twinax Cabling

Driven by the never-ending requirement for faster data-rate transmission, Ethernet technology has continually evolved from 1GbE to 10GbE and eventually to 100GbE. This demand for faster application speed has also spurred technological evolution on data carrying techniques. Consequently, fiber and copper transmission standards has been progressed, providing greater bandwidth for transporting data over Ethernet architectures with reduced cost and complexity. In today’s article, some detailed information will be provided on 10G SFP+ twinax cabling.

Why Implementing 10G SFP+ Twinax Cabling?
Many research companies forecast that 2016 will be the year of 100G. So why implementing 10G twinax cabling here? There are several reasons which will help you sort this out. Regardless of cost, most LAN infrastructures employ a mixture of copper and fiber premises wiring. 10GbE bandwidth are generally sufficient to support the transfer and streaming of large data, video and audio files. Thus there are no demands for greater network performance or application bandwidth. What’s more, costs associated with re-cabling a network can be exorbitant and organizations should take precautions to ensure their cabling systems can last well into the future. 10GbE twinax cabling provides the best assurance for being able to support forthcoming technologies and delivers utmost investment protection.

What Is 10G SFP+ Direct Attach Twinax Cable?
SFP+ Direct Attach Cable (DAC) is a copper 10G Ethernet cable which comes in either an active or passive twinax cable. The difference between them is that an active twinax cable has active electronic components in the SFP+ housing to improve the signal quality while a passive twinax cable is just a straight “wire” and contains few components. As such, they support different transmission distance. SFP+ DAC cables use SFP+ MSA and copper “twinaxial” cable with SFP+ connectors on both sides providing 10 Gigabit Ethernet connectivity between devices with SFP+ interfaces, which is expected to be the optimum solution for 10G Ethernet reaches up to 10 m.

Passive SFP+ Twinax Cable Assemblies
The passive SFP+ twinax cable is designed to support connections for 10 Gigabit Ethernet or Gigabit Ethernet switches with 10 Gigabit Ethernet uplink. Passive SFP+ cables, as noted before, have no electrical components and typical cover a distance of 1m, 3m, and 5m. For example, compatible Cisco SFP+ cables from Fiberstore like SFP-H10GB-CU3M, SFP-H10GB-CU1M, and MA-CBL-TA-1M, are programmed specifically to work with Cisco equipment. When these cables are plugged into Cisco equipment, they will not trigger the warning message that a non-Cisco transceiver has been detected. Figure 1 shows compatible Cisco SFP-H10GB-CU3M SFP+ to SFP+ passive copper cable with SFP+ connectors.

SFP+ Passive Copper Cable with SFP+ connectors

Active SFP+ Cable Assemblies
Active SFP+ twinax cables, compared with passive SFP+ cables can support longer transmission distance of 7m and 10m or up to 15m (distance may vary from vendors to vendors). For designs that only support SR and LR applications, active direct attach copper cable assemblies provide functions such as transmit disable and receiver loss of signal in addition to signal amplification, which makes it ideal for highly cost-effective networking connectivity between switches and servers. Figure 2 shows an active copper SFP+ DAC cable with SFP+ connectors.

SFP+ Active Copper Cable with SFP+ connectors

From these two pictures, we can see that there is no visual difference between active and passive SFP+ twinax cables. So, people should read the product specifications carefully before purchasing twinax cables.

Summary
SFP+ twinax cables offer a cost-effective way to interconnect 10G Ethernet devices within racks and across adjacent racks. These cables are usually accommodated into the SFP+ transceiver housing of a switch or server. Fiberstore SFP+ twinax DAC cables provide robust connections for leading edge 10GbE systems. We provide a full range of SFP+ DAC cables including SFP-H10GB-CU3M, SFP-H10GB-CU1M, EX-SFP-10GE-DAC-1M, JD097C, JD095C, etc. These SFP+ twinax cables are fully compatible with major brand. For more detailed information, please visit www.fs.com or contact us over sales@fs.com.

Difference Between Passive and Active Twinax Cable Assembly

Twinax cableOptical fiber cabling had gone through rapid development over recent years and maintained its leading role in telecom field. While twinax cable still remained a good way to access the networking industry trends over the last three decades and presented the highest longevity among all media. Twinax cable (see in following Figure) is a type of cable similar to coaxial cable that has two inner conductors instead of one. And owing to its cost efficiency, it is commonly used in short-range high-speed differential signaling applications. Currently there is a twinax cable which comes in either passive or active copper cable. So what is the difference between them? Today’s passage will provide a satisfying solution to you.

Describing Passive and Active Twinax Cable
A passive cable carries a signal over short lengths (5m or under) of copper with no additional components to boost signal. While an active copper twinax cable contains electrical components in the connectors that boost signal levels. This makes active twinax cables a little more expensive than passive copper twinax cables; however, they can connect the Converged Network Adapter (CNA) to a top-of-the-rack switch over longer distances than passive twinax cables.

Twinax Active vs. Passive: How to Choose the Right Twinax Cable?
Length and signal strength are always two important factors you should look into when requiring a cable for an application. Typically, we can see passive twinax cables being used between the server and the Top of Rack (ToR) switch. The upside in this configuration is that the passive twinax cabling connection is much cheaper than the cost of an optical link. The downside is that you are limited in distance and there’s also some cable interoperability issue you’ll need to deal with. Passive twinax cables are rated for ranges up to 5m and provide a good working solutions at a great cost.

When the distance between connection points exceeds 5m, it is highly recommended to use active twinax cables to ensure signal is transferred all the way through. The downside is that they are more expensive and use more power. The upside is that you don’t have to worry about distance (up to 300 meters) and, perhaps more importantly, you don’t have to worry about which vendor’s cable you use and the signal is improved and gives peace of mind by creating a trustworthy connection. In regards to active versus passive twinax cables, it depends on what you are connecting together.

QSFP+ Copper Cables—A Cost-effective Application of  Twinax Cable
QSFP+ direct attach copper cable assemblies offer a highly cost-effective way to establish a 40 Gigabit link between QSFP+ ports of QSFP+ switches within racks and across adjacent racks. QSFP+ cable is an extension of the established interface system SFP+ that is mainly used in short distance. 40G QSFP+ to 4SFP+ copper breakout cable and QSFP to QSFP copper direct attach cable are the two common types of 40G QSFP+ copper twinax cables.

QSFP to 4SFP+ twinax breakout cables are suitable for very short distances and offer a very cost-effective way to connect within racks and across adjacent racks. Take QSFP-4SFP10G-CU1M as an example, this breakout cable connects a 40G QSFP port and four 10G SFP+ ports of Cisco switches and operates at a link length of 1m. While a QSFP+ to QSFP+ passive copper twinax cable consists of a cable assembly that connects directly into two QSFP+ modules, one at each end of the cable. This cable use integrated duplex serial data links for bidirectional communication and is designed for data rates up to 40Gbps. There are various QSFP+ to QSFP+ passive twinax cables branded by famous brands, like Cisco, HP, Juniper, Brocade, etc. The following picture shows a Cisco QSFP-H40G-CU3M Compatible QSFP+ to QSFP+ passive copper cable.

Cisco QSFP-H40G-CU3M

Summary
There isn’t a truly visual way to tell the difference between active and passive twinax cables. Therefore when you are requiring a twinax cables, please follow the instructions that I have listed above or you should ask your vendors for expertise suggestion. FS.COM offers a large variety of SFP+ cables and QSFP+ twinax cables that are well tested and compatible with major brand. If you have any inquiry of our products, please feel free to contact us.

Introduction to 25G and 40G Ethernet Network

When you look at the evolution of networking and the data that drives it, there is no surprise that Ethernet has been and will continue to be the most widely used network interface. Consumers and network designers wish to smoothly migrate to higher network speed—100G/400G without compromising quality. Ethernet speed upgrade path was clearly defined as from 10G,40G to 100G. But recently a new migrate path (10G-25G-100G) was gradually accepted by subscribers. For those who need to migrate their network to adopt to the big data age, choose 25G or 40G Ethernet, that is the question! This article provides the pros and cons of 25G and 40G Ethernet network. You will get your own answer at the end of it.

25G or 40G

Here Comes 25 Gigabit Ethernet
25 Gigabit Ethernet has passed the first hurdle in the IEEE standards body with a successful Call for Interest (CFI) in July, 2014. It is a proposed standard for Ethernet connectivity that will benefit cloud and enterprise data center environments. 25 GbE leverages technology defined for 100 Gigabit Ethernet implemented as four 25 Gbit/s lanes (IEEE 802.3bj) running on four fibers or copper pairs. Telecom giants like Google, Microsoft, Arista, and Mellanox are pushing the development of a 25 Gigabit Ethernet standard for top-of-tack server networking. Relevant transceiver modules and optical cables are developed to support this technology.

40G Ethernet Network
The IEEE P802.3ba 40G and 100G Ethernet Task Force was formed to develop a 40 Gigabit Ethernet and 100 Gigabit Ethernet draft standard. At the physical layer, 40G Ethernet is essentially 4×10G lanes. Standards-based 40G Ethernet switches and routers are starting to show up in enterprise networks, following ratification of the IEEE 802.3ba specification in mid-2010. QSFP+ modules and 40G DAC cables are introduced to back 40G networking, which are warmly welcomed by network designers. For example, QSFPP-4X10GE-LR (see in Figure 2) is compatible Juniper QSFP+ transceiver. It can be used in a 4×10G modules with 10GBASE-LR interfaces.

Juniper QSFPP-4X10GE-LR

25 Gigabit or 40 Gigabit Ethernet for Your Server
The most obvious feature of 25 Gigabit is described in two words—single lane. The phrase refers to the electrical signaling on the chip that would power an Ethernet port, while the design of 40 GbE was based on 10 GbE. Originally, 100 GbE had a similar heritage, with its initial design in 2010 using 10 lanes of 10 Gbps. This is the first generation of 100G transport links. As standards bodies sought to improve the efficiency of 100 GbE in the coming years, its second generation consists of four lanes of 25 Gbit/s Ethernet on four fiber or copper pairs. This will be disruptive to the 10G and 40G infrastructure.

In addition, the proposed 25 GbE standard reduces the number of lanes on the chip makes it less expensive to produce and less power-hungry. It also simplifies the process with just minor changes for forward error correction and lane alignment when compared to 40 GbE. To sum up, getting 25 GbE performance for the same price of 10G combined with reduced operating costs, which makes itself a compelling proposal for migration.

On the other hand, driven by cloud computing, mobile broad-band and IPTV for higher user bandwidth, demand for 40G transport links is growing quickly. 40G links has been deployed for more than 5 years. Compared to 25GbE, it has a longer history. And a good news is that advances in semiconductor technology and innovative designs are reducing the cost of 40G systems. High-speed serial links, flexible interfaces, integrated packet, lower power and less silicon real estate are all helping telecom manufacturers deliver cost-effective solution to upgrade from 10G to 40G.

The 40GbE specification defines a wide range of port types and has been ratified by IEEE. 40G optical equipment are all compatible with the existing 10G devices. Take 40G-QSFP-4SFP-C-0101 (see in Figure 3) as an example, it is the compatible Brocade QSFP+ to 4SFP+ Passive Breakout Copper Cable, which offer a cost-effective way to establish a 40G link between QSFP port and SFP+ within racks and across adjacent racks. However, 25GbE transceiver modules like QSFP28 and SFP28 will not be compatible with the existing QSFP+ and SFP+ cable assemblies. Which will cause trouble to users. Many experts believe that if people agree to add 40GbE instead of endlessly debating will lead to faster standards completion.

Brocade 40G-QSFP-4SFP-C-0101

Right Move at the Right Time
Planning for migration to higher-speed Ethernet can feel daunting as telecom experts hold different opinions towards the future of 25G and 40G. Some believe that the dominant next-generation server connection speed is going to be 25G, but some confirm that 40G between switches is expected to remain and will not be affected by this development. Just remember to make the right move at the right time. Fiberstore is working on providing cost competitive longer reach option for mainstream customers. We are very glad to offer our expertise in choosing the physical infrastructure that best meets your needs.