Focus On Fiber Optic Link Loss

We know that, no natter what component you use, there must insertion loss in your fiber optic cabling. Therefore, in order to make your fiber optic cabling system perform at high level, calculating the amount of insertion loss before cable plant is necessary. This article will focus on fiber optic link loss.

Overview of Link Loss And Link Loss Budget

The link loss and link loss budget are measured in dB. Link loss is the total insertion loss of all optical components in an optical network. While link loss budget is the amount of loss that a cable plant should have. It is calculated by adding the average losses of all the components used in the cable plant to get the total estimated end-to-end loss. The link loss budget has two important functions: during the design stage to ensure the cabling being designed will work with the links intended to be used over it and; after installation, comparing the calculated link loss to test results to ensure the cable plant is installed properly.

How to Calculate Link Loss?

Usually, the loss of four parts need to be calculated: mated pair connector loss, fiber optic splicing loss, fiber optic cable loss and other loss.

link loss calculation

  • Mated Pair Connector—EIA/TIA 568 standard allows 0.75 max per connector

Connector or “connection” loss is the total loss of the mated pair connectors. It’s standard to assume a 0.3 dB loss for most ultras polished connectors. In order to measure the loss of the connectors, you must mate them with similar connectors, or you are likely to experience different losses. Also, a high quality connector is required when testing matted pairs.

  • Fiber Optic Splicing—EIA/TIA 568 max loss is 0.3 dB per splice

According to the Fiber Optic Association (FOA), multimode splices are commonly made using mechanical splices. Best construction practices dictate that even with multimode fiber fusion splicing is ideal. Both forms of splicing generally result in satisfactory results, however fusion splicing proves to be more reliable in adverse surroundings. Single mode fibers that have been fusion spliced will typically have less than 0.10 dB loss. A good average for a skilled installer is generally around 0.05 dB loss.

  • Fiber Optic Cable

EIA/TIA 568 spec for multimode fiber is 3.5 dB/ km at 850 nm and 1 .5 dB/km at 1310 nm. This specification translates into a loss of approximately 0.1 dB per 100 feet for 850 nm, 0.046. dB per 100 feet for 1300 nm. For example, 300 ft multimode fiber optic cable at 850 nm would approximately equal 0.3 dB loss. While for single mode fiber, the loss is 0.5 dB per km at 1310 nm, 0.4 dB per km for 1550 nm.

  • Other Loss—Passive Components and Margin

Don’t forget to count any other passive components you are using in your network. For example, if you are using splitters or filters, add the insertion loss for those components. In addition, it is recommended to add margin to your link loss calculation to adjust for any unforeseen losses. The amount may vary by designer or application but typically 2-3 dB will allow for sufficient headroom in you network link loss calculation.

Conclusion

The fiber optic link loss calculation and analysis are vital in cable plant. After the cable plant is installed, the calculated loss values are compared with the test results to ensure the link can operate properly. Besides, to reduce the link loss, high quality components are required. Quality is everything when gigabit and higher speeds are required. FS.COM provides high quality fiber optic connector, fiber optic cable and fiber optic transceiver at reasonable price. Also, test tools can be found here, such as light source and power meter. For more details, you can visit our site.

Advertisements

How Far Can 25G Ethernet Go?

Seeing from the evolution of data transmission speed and size of data centers, it is not difficult to find that the pressure on the data centers to manage data quality and transmission speed continues to grow, which leads to the need for faster data transmission over the network. Ethernet industry has laid a path to higher networking speeds like 100GbE, and 25G Ethernet has been developed to provide a simpler path to future Ethernet speeds of 50 Gbps, 100 Gbps and beyond. The release of the 25GbE specification provides cost-effective solution for server-to-switch connectivity. However, network will not stop the pace of development. How far can 25G Ethernet go? This article is going to focus on the question.

Overview of 25G Ethernet

25G Ethernet is a standard for Ethernet connectivity in a datacenter environment, developed by IEEE 802.3 task force P802.3by. The IEEE 802.3by standard uses technology defined for 100 Gigabit Ethernet implemented as four 25 Gbps lanes (IEEE 802.3bj). In 2016, 25G Ethernet equipment was available on the market, such as 25G SFP28 transceiver and DAC cable. In addition, 25G Ethernet supports for 100G using QSFP ports that can be converted to 4 lanes of 25 Gbps, like 100G QSFP28 transceiver. Here is a table of 25G Ethernet specification for you.

25G Ethernet specification

Advantages of 25G Ethernet

For 10G ToR to 10G Server connectivity, the simplest cabling solution is to use two 10G SFP+ transceivers and one fiber optic cable. When the network has to be upgraded to 25G Ethernet, the data center manager only needs to replace 10G SFP+ transceivers with 25G SFP28 transceivers. In the same way, we know that in 40G ToR to 10G Server connectivity, one 40G QSFP+ transceiver, four 10G SFP+ transceivers and one MTP to LC breakout cable are utilized. When this network deployment is upgraded to 100G ToR to 25G Server connectivity, the work can be quickly finished by replacing 40G QSFP+ transceiver with 100G QSFP28 transceiver, four 10G SFP+ transceivers with four 25G SFP28 transceivers. It can be easily found that there are some advantages when upgrading from 10G to 25G or 40G to 100G:

  • It can offer both CapEx and OpEx savings through backward compatibility, for investment protection and seamless migrations with consistent rack-design and reuse of the existing cabling infrastructure, avoiding costly and complex changes.
  • The technology utilized in 100G to 25G connectivity is similar to that in 40G to 10G connectivity, but the performance is increased by 2.5 times, thus reducing the power and cost per gigabit significantly.
  • 25G Ethernet provides higher port and system density than a comparable 40G solution.
  • Both power savings and higher density results in lower cooling requirements and operational expenditure for data center operators.

advantages of 25G Ethernet

How Far Can 25G Ethernet Go?

Considering the significant benefits and compelling economics of 25G Ethernet, it is no surprise that the move to 25GbE is accelerating—a recent five-year forecast by industry analysts at the Dell’Oro Group predicts 25G Ethernet will be the dominant Server port speed for new systems by 2018. You can learn about it from the following figure.

forecast for 25G Ethernet

However, never underestimate the need for industry consensus building. At present, 25GbE is mainly used for switch-to-server applications. If it can realize switch-to-switch application, 25G Ethernet may go further.

Conclusion

To be frank, 25G Ethernet indeed gains ground in some aspects compared to 10G and 40G Ethernet. If you plan to deploy 25GbE network, you can visit FS.COM which provides quality 25G SFP28 transceiver and various fiber optic cables.

Originally published at: http://www.fiber-optical-networking.com/how-far-can-25g-ethernet-go.html

10GBASE-T Cabling Vs. 10G SFP+ Cabling in 2017

When it comes to 10G network, we usually make a choice between 10GBASE-T cabling and 10G SFP+ cabling. In fact, many people still prefer 10G SFP+ cabling that uses SFP+ DAC cable, because they think it matches better for the requirements and emerging trends of today’s data center. Now the 10G network is quickly becoming mainstream, especially on consumer desktop systems. That means the cost of 10GBase-T switches will need to come down. Also, other “IOT” home components that decide to offer 10G will probably go for 10GBASE-T, such as game consoles, streaming boxes, etc. So, do you still recommend 10G SFP+ over 10GBASE-T nowadays for network deployment? This article will discuss this topic.

10GBASE-T Vs. 10G SFP+

Vote for 10GBASE-T
  • The 10GBASE-T ports are physically smaller which is important for non-data center devices. They are also easier to use. You just plug in an ethernet cable and it works. No need to deal with optical transceiver compatibility and all of those problems.
  • 10GBASE-T cabling is backwards compatible with 1G ports which will still be used for things like IPMI and other low bandwidth devices. You could just get one 10GBASE-T switch and connect up everything you have to it. Going with 10G SFP+ makes it difficult to find something that juggles enough of both kinds of ports for all of your 10G and 1G devices.
Vote for 10G SFP+
  • 10G SFP+ is better for future-proof cabling system. You can migrate to 40G QSFP+ smoothly and keep the existing cables. Even OM4 can do 100Gbps up to 150 meters. It is not known if Cat6a, Cat7 or even Cat8 will be able to pull off anything above 10Gb. And this will be stuck at 10G for quite some time.
  • 10G SFP+ interface that has been widely deployed for 10G ToR switches continues to use less power, typically less than 1 W per port. It also offers better latency—typically about 0.3 microseconds per link. While 10GBASE-T latency is about 2.6 microseconds per link due to more complex encoding schemes within the equipment.
  • 10GBASE-T switches are still expensive and there is a very limited choice of those that actually work. Also 10GBASE-T NICs add a premium over 10G SFP+. From a cost perspective, it is cheaper to go the 10G SFP+ cabling since you can find so many used 10G switches for deals, along with decent NICs. In addition, there is more support, driver wise for 10G SFP+ NICs than 10GBASE-T.

By comparison, we find that if flexibility and scalability are more important, 10GBASE-T cabling is a better option; but if power consumption and lower latency are critical, 10G SFP+ cabling may be more suitable. We also find that the cost of 10GBASE-T cabling is no longer in the ascendant. If 10GBASE-T want to acquire an absolute advantage, the primary goal now is to get 10GBASE-T cheaper and more power efficient and bring the cost way down so it can finally replace Gigabit as the next base level networking.

A Third Choice

If you do not have to choose vanilla or chocolate, you could have both 10GBASE-T and 10G SFP+ in the same switch, such as Ubiquiti EdgeSwitch 16 XG and UniFi Switch 16 XG. Both of them feature twelve 10G SFP+ ports and four RJ45 10GBASE-T ports to efficiently deliver and aggregate data at 10G speeds. But some people point out that the 10GBASE-T ports on the Ubiquiti switches actually don’t work reliably at 10Gbps speed. Therefore, before you buy it for those four RJ45 10GBASE-T ports, you have to make sure that they can work without issues. Here is a figure of them for you.

Ubiquiti EdgeSwitch 16 XG and UniFi Switch 16 XG

Conclusion

If you were building out a 10G cabling system from scratch today, which technology would you choose for your 10G network connectivity? Both 10GBASE-T cabling and 10G SFP+ cabling have their own advantages. And both of them occupy an important position in the future of network design and best practices. As for which one to choose, it all depends on your specific need. FS.COM can provide cost-effective solution for your 10G network deployment, such as Cat5e bulk cable, 10G SFP+ transceiver, 10G SFP+ DAC cable, 10GBASE-T SFP+ Transceiver and so on. For more details, please visit our site.

Originally published at: http://www.fiber-optical-networking.com/10gbase-t-cabling-vs-10g-sfp-cabling-in-2017.html

Applications of FHX Ultra MTP/MPO Cassettes

Nowadays, data communication technology has developed rapidly. To achieve high speed transmission, it is very common to see complex cabling system in data center, which may even include thousands of fibers. Under such circumstances, saving space in data center is a critical issue. Therefore, fiber optic components or cabling solutions which are characterized by high density will gain the popularity among data center managers. MTP component is such one that can satisfy the requirement. And this article is going to introduce FHX ultra MTP/MPO cassettes and their applications in data center.

Overview of FHX Ultra MTP/MPO Cassettes

MTP/MPO cassette is widely used for high-density cabling in data centers. It is pre-terminated and pre-tested enclosed unit which can provide secure transition between MTP and LC, SC or MTP discrete connectors. And it is usually structured with LC, SC or MTP adapters on the front side of the cassette and MTP adapters at the rear of the cassette. FHX Ultra MTP/MPO cassette has three types: FHX ultra 8F MTP-LC cassette, FHX 12F MTP-LC cassette and FHX MTP conversion module. Here is a figure for you to have a better understanding of these three types of MTP cassettes.

FHX Ultra MTP MPO Cassettes
Applications of FHX Ultra MTP/MPO Cassettes

For application, MTP cassette can be easily found in 10G, 40G and 100G network applications in data center.

FHX Ultra 8F MTP-LC Cassette

Since both FHX ultra 8F MTP-LC cassette and FHX 12F MTP-LC cassette serve to realize the transition from small diameter ribbon cables terminated with MTP connector(s) to the more common LC interfaces used on the transceiver terminal equipment, this part will take FHX ultra 8F MTP-LC cassette as an example. The FHX ultra 8F MTP-LC cassette is structured with four LC duplex (8-fiber) adapters on the front side of the cassette and one 12-fiber MTP adapter at the rear of the cassette, and it is often used for 10G to 40G connection. As the following figure shows, we can also add FHX ultra enclosure and FHX MTP adapter panel to the cabling solution. From the left to the right, four 10G SFP+ transceivers are plugged into four 10G ports on the 10G switch. Then they are connected to LC adapters on the FHX ultra 8F MTP-LC cassette through four LC duplex patch cables. The cassette is installed in the FHX ultra enclosure. One MTP trunk cable connects two MTP adapters respectively on the rear of the cassette and MTP adapter panel. Finally, the 40G QSFP+ transceiver on the 40G switch is connected with MTP adapter on MTP adapter panel through another MTP trunk cable. In this application, 100% fiber utilization is realized. What’s more, the 1U fiber enclosure can house 18 x 8F FHX cassettes or 12 x 12F FHX cassettes, with the total fiber capacity up to 144 fibers for LC interface, greatly saving cabling density.

application of FHX ultra 8F MTP-LC cassette
FHX MTP Conversion Module

The FHX MTP conversion module has several kinds, this part will take 3x MTP-8 to 2x MTP-12 (24-fiber) conversion module as an example. This kind of FHX MTP conversion module is structured with three 8-fiber MTP adapters on the front side of the module and two 12-fiber MTP adapters at the rear of the module. We can use FHX ultra enclosure to hold MTP conversion module. The following figure shows the cabling solution for 120G to 120G connection. Three 40G QSFP+ transceivers are respectively plugged into 40G ports on three 40G switches on both sides. Then the three 40G QSFP+ transceivers are connected with three 8-fiber MTP adapters on the front side of the module through three MTP trunk cables. Finally, two 12-fiber MTP adapters at the rear of two respectively modules are connected through two MTP trunk cables. This cabling solution utilize Based-8 MTP cabling system and achieves 100% fiber utilization. With the use of 1U FHX ultra enclosure, twelve 3x MTP-8 to 2x MTP-12 conversion module can be used in this cabling solution, which creates a 33% spacing-saving upgrading path.

application of FHX MTP conversion module
Conclusion

The FHX ultra MTP/MPO cassettes can not only meet the need for saving space in data center cabling, but also realize 100% fiber utilization during the cabling. With superior best-in-class features, FS.COM FHX ultra MTP/MPO cassettes can offer you cost-effective, simple 10G to 40G, 40G to 40G, 40G to 100G or 120G to 120G cabling solutions and ensures high performance at the same time. For more details, please visit our site.

Deploy 40G/100G in Your Data Center

Due to the massive amount of storage is needed for high bandwidth, the demand for higher capacity of network deployment is rapidly increasing. Obviously, the conservative 2-fiber transmission is not enough to satisfied the need. And 12 or 24-fiber 40/100G Ethernet migration is quickly becoming a hot spot. This article will provide some cabling solutions for 40G/100G cost-effective and simplified migration path in data center.

10G to 40G

Take parallel optical transceiver 40GBASE-SR4 QSFP+ for example, it is structured with 12-fiber MTP connector, so it is used with 12-fiber MTP cable (only eight fibers are used, four for transmit and four for receive). The following figure shows the simplest way for migration from 10G to 40G. We can utilize 40G MTP/MPO breakout cable which has an MTP/MPO connector on one end and four duplex LC connectors on the other end. The MTP/MPO connector end is plugged into the MTP/MPO connector interface of 40GBASE-SR4 QSFP+ transceiver, while the other end is connected with four 10G SFP+ transceivers.

10G to 40G
10G to 100G

As for migration from 10G to 100G, we can utilize 100GBASE-SR10 CFP transceiver and 100G MTP/MPO breakout cable. The 100GBASE-SR10 CFP transceiver is structured with 24-fiber MTP/MPO connector interface. When using with MTP/MPO 24 fiber cable, the 100GBASE-SR10 transceiver only uses twenty fibers, ten for transmit and ten for receive. The following shows that one 100GBASE-SR10 CFP transceiver and ten 10G SFP+ transceivers are connected by MTP breakout cable which has 24-fiber MTP/MPO connector on one end and ten duplex LC connectors on the other end. This is the simplest cabling solution for 10G to 100G connectivity.

10G to 100G
40G to 40G

For 40G to 40G connectivity, we can use 12-fiber MTP trunk cable and MTP/MPO adapter panel to connect two 40GBASE-SR4 QSFP+ transceivers. We know that when deploying MTP link, we have to take polarity into consideration. Here are two cabling solutions for you. The first one uses Type A and Type B MTP trunk cable; the second one only uses Type B MTP trunk cable.

40G to 40G
100G to 100G

For 100G to 100G connectivity, here are three cabling solutions. The first one uses two 24fiber MTP-LC fanout cables, two 12-fiber MTP trunk cables and two MTP adapter panels; the second one uses three 24-fiber MTP trunk cables and two MTP adapter panel; the third one uses two duplex LC patch cables, two MTP cassettes and one 24-fiber MTP trunk cable. However, the third cabling solution does not use 100GBASE-SR10 CFP transceiver. It deploys ten 10G SFP+ transceivers on both sides to achieve 100G to 100G data transmission.

100G to 100G
Conclusion

With the rapid development for data communication, the migration from 10G to 40G or 100G is inevitable. Then how to deploy 40G or 100G in data enter becomes the primary concern. All the transceivers and cabling assemblies presented in 40/100G connectivity solution are available in FS.COM. For more details, please visit our site or contact us via sales@fs.com.

Practical Knowledge About MTP Fiber Testing

High density cabling is common in today’s data centers. Characterized by fast installation, high density and high performance cabling, MTP fiber optic cable has become the common cabling solution to satisfy the ever increasing bandwidth requirements of data centers, such as MTP MPO fiber breakout cable, SM MTP trunk cable, MTP conversion cable and so on. We know fiber testing is a key step to ensure the high performance of the network deployment. However, with complicated structure, MTP fiber testing is not an easy job. This article share some practical knowledge about MTP fiber testing.

MTP fiber optic cable

Challenges of MTP Fiber Testing

Challenge 1. MTP fiber optic cable is pre-terminated fiber whose quality can be only guaranteed as it exists in the manufacturer’s factory. Out of the factory, it must be transported, stored, and later bent and pulled during installation in the data center. There are all kinds of performance uncertainties before deployment. Proper testing of pre-terminated cables before installation is the only way to guarantee performance in a live application.

Challenge 2. MTP fiber optic cable has polarity. The simple purpose of any polarity scheme is to provide a continuous connection from the link’s transmitter to the link’s receiver. For MTP/MPO apc connector, TIA-568-C.0 defines three methods to accomplish this: Methods A, B and C. It is common to make deployment mistakes because these methods require a combination of patch cords with different polarity types.

Challenge 3. Migration from 10G to 40G and 100G is common. Though this migration strategy is an efficient way to leverage the existing cabling, in comparison to 10G connection, the 40G and 100G standards call for different optical technology (parallel optics) and tighter loss parameters. In all, it is necessary to verify the links to ensure that the performance level achieves the requirement of the network deployment.

Proper MTP Fiber Testing

The proper MTP fiber testing is simple and quick enough, typically under 10 seconds per fiber. Test all 12 fibers—the whole cable—simultaneously and comprehensively (including loss, polarity). That sort of test capability changes the fiber landscape, enabling installers and technicians to efficiently validate and troubleshoot fiber—flying through the process by tackling an entire MPO 12 cable with the push of a button.

The tools used to carry out the test are available on the market, such as Metal Texture-400X Desktop Video Three-dimensional Microscope, Optical Power Meter, Optical Light Source and so on. These tools promise to save testing time and labor costs up to 95% over individual fiber tests.

Conclusion

The increasing demand for higher density cabling and data transmission rate is driving network technology to evolve at an ever increasing pace. To get high performance of network deployment, fiber testing cannot be ignored. As MTP fiber optic cable has been widely deployed, MTP fiber testing is an important step before installation. I hope after reading this article, you can learn more about MTP fiber testing. In addition, the fiber testing tools mentioned above can be found in FS.COM. If you want to know more details, please visit our site.

A Closer Look at 40G QSFP+ SR4 Transceiver

As 40G network has been widely applied in today’s data center cabling system, 40G QSFP+ transceivers gain great popularity among data center managers. And for short data transmission distance, 40G QSFP+ SR4 transceiver is preferred. This article is going to focus on 40G QSFP+ SR4 transceiver and share several cabling solutions for 40G QSFP+ SR4 with you.

Overview of 40G QSFP+ SR4 Transceiver

40G QSFP+ SR4 transceiver is a parallel fiber optic transceiver which means it uses four fibers for transmitting and four fibers for receiving at the same time. Designed with MTP/MPO interface, 40G QSFP+ SR4 transceiver is used together with multimode fiber, such as OM3 and OM4. Working on wavelength of 850 nm, 40G QSFP+ SR4 transceiver can support 40G fiber optic transmission with the link length up to 100 meters over OM3 fiber and 150 meters over OM4 fiber. For application, 40G QSFP+ SR4 transceiver can be used for 10G to 40G and 40G to 40G connections. Here is a figure of 40G QSFP+ SR4 transceiver for you.

40G QSFP+ SR4 transceiver

10G to 40G Connection

Since 40G QSFP+ SR4 transceiver uses four independent full-duplex transmit and receiver channels, the 40G optical signal can be split into four 10G optic signals. Therefore, we can increase the fiber count at the 10G distribution end to realize 10G to 40G connection. As the following figure shows, we can use 12f MPO trunk cable and fiber enclosure. Four 10G SFP+ SR transceivers are inserted into 10G ports on one side, while one 40G QSFP+ SR4 transceiver is inserted into 40G port on the other side. Then the four 10G SFP+ SR transceivers are connected with four duplex LC patch cables which are plugged into LC ports on the front side of MPO fiber cassette inside the fiber enclosure, and the 40G QSFP+ SR4 transceiver is connected with 12f MPO trunk cable which is plugged into MTP/MPO port on the rear of MPO fiber cassette. Finally, the whole optical link is completed.

40G QSFP+ SR4 transceiver for 10G to 40G connectionA

We can also use MPO to LC fanout and MTP fiber patch enclosure which includes MTP fiber adapter panels. This cabling solution is similar to the previous one, but the difference is that the four 10G SFP+ SR transceivers are connected with MPO to LC fanout which is plugged into MTP/MPO port on the MTP fiber patch enclosure. The scenario is shown in the following figure.

40G QSFP+ SR4 transceiver for 10G to 40G connectionB

40G to 40G Connection

The following figure shows the simplest scenario for 40G to 40G connection. Two 40G QSFP+ SR4 transceivers are separately inserted into two 40G switches. Then the two 40G QSFP+ SR4 transceivers are connected by 12f MPO trunk cable.

40G QSFP+ SR4 transceiver for 40G to 40G connectionA

We can also use MTP fiber patch enclosure to achieve better cable management and higher density cabling. The scenario is shown in the following figure. With the use of MTP fiber enclosure, cable management for 40G to 40G connection could be easier. A 48-port 1U rack mount MTP fiber patch enclosure includes up to four 12-port MTP fiber adapter panels with MPO MTP fiber optical adapters on it, here is a figure for you.

40G QSFP+ SR4 transceiver for 40G to 40G connectionB

Conclusion

Designed with parallel transmission mode, 40G QSFP+ SR4 transceiver has a wide range of cabling applications with great flexibility. The cabling solutions mentioned above are just several commonly used ones. As for detailed cabling solutions for 40QSFP+ SR4 transceiver, it is suggested to depend on the practical applications and cabling environments. I hope after reading this article, you can learn more about 40G QSFP+ SR4 transceiver.