Introduction to 10GbE/25GbE/40GbE/100GbE Fiber Optic Cabling

Technology is changing rapidly. Just when you got used to Gigabit Ethernet speeds being a fast & reliable system, someone unveiled 10GbE, 25GbE, 40GbE or even 100GbE systems a few years later. The newer and higher performing iterations are indeed the great breakthrough for telecommunication industry, but also pose difficulty in choosing network migration path—10G to 40G to 100G, or to 25G to 50G to 100G. We have described 10G, 25G, 40G and 100G Ethernet technology before, now in this blog, we’d like to introduce the four fiber optic cabling, and compare two 100G migration paths.

Cost-effective 10GbE Fiber Optic Cabling

10 Gigabit Ethernet technology defined by IEEE 802.3ae-2002 standard, is matured nowadays. Just like the “old” Gigabit Ethernet, 10Gb network can be terminated with either copper or fiber cabling. 1000BASE-T standard usually uses the Cat5e cables as the transmission media, while 10GbE bandwidth requires high grade copper cables like Cat6/Cat6a/Cat7 cables to support 10Gbps data rate. For instance, 10G SFP+ 10GBASE-T transceiver modules utilize Ethernet copper cables (Cat6a/Cat7) for a link length of 30m. SFP+ direct attach cables (DAC) and active optical cables (AOC) are also regarded as the cost-effective solutions for 10G short-reach applications. Besides 10G copper cables, there are single-mode (OS2) and multimode fiber patch cables (OM3/OM4) applied to different 10GbE IEEE standards. For the detailed information about the 10G cabling options, please see the following table.

As to the 10G fiber optic transceivers, there are a series of optical form factors including the XENPAK, X2, XFP, SFP+. The former three 10GbE optical transceivers were released earlier than smaller 10G form factor—SFP+ module. However, owing to their larger footprint, they are not successful on the 10G hardware market. Furthermore, SFP+ optics, compliant with several IEEE standards (SR, LR, LRM, ER, ZR and 10GBASE-T...) wins the heart of 10G end-users.

Singe-lane Design Makes 25GbE Shine

When 25G Ethernet was developed to support a single-lane 25Gbps standard in 2014, it was treated as the “new” 10GbE technology but delivers 2.5 times more data. Compared to 40GbE that was based on 10GbE, 25GbE with one lane obviously improves the port density and cost requirement. 25GbE network can support both copper and fiber optic cables, seen in the below table.Similar to 10GbE networks, 25G Ethernet physical interface specification supports several 25Gbps capable form factors, including CFP/CFP2/CFP4, SFP28 (1x25 Gbps) and QSFP28 (4x25 Gbps), which is also used for 100GbE. SFP28 25GBASE-SR and 25GBASE-LR SFP28 are two popular 25GbE optical transceiver modules available on the market, the former supports up to 100m link length while the latter allows a maximum transmission distance of 10 km.

The available optical switches of the market do not support direct 25GbE connections using an SFP28 direct attach copper (DAC) cable. It is recommended to use a breakout cable that allows four 25GbE ports to connect to a 100GbE QFSFP28 switch port. FS.COM SFP28 DAC cable lengths are limited to four meters (1m, 2m, 3m, 5m) for 25GbE. And if you prefer a longer length, the 25GbE active optic cable (AOC) solutions are good recommendations.

25G Optics SFP28	Type	Media/Reach
All 25G SFP28 Ports	25GBASE-SR	50µm MMF / 70m
	25GBASE-LR	9µm SMF / 10km
	25GBASE-AOC	Pre-terminated in 3, 5, 7, 10, 15, 20, 25, 30m lengths
	OM4 MMF MTP/MPO	150m
25G Copper SFP28	Type	Media/Reach
All 25G SFP28 Ports	25GBASE-CR Twinax / 'Direct Attach'	Pre-terminated in 1m, 2m, 3m, 5m lengths

Fast & Reliable 40GbE Fiber Optic Cabling

Like the 10GbE fiber optic cabling, there are several IEEE standards of 40GbE transceiver in the whole evolution. 40G QSFP+ optical transceivers are the most commonly used optics for 40G network. So how to choose fiber optic cables for 40G optical transceivers? The following table will help you out.

Besides the QSFP+ fiber transceivers and fiber optic cables, 40G DAC cables available in QSFP+ DAC cables and AOC cables enable short-reach options. For 40G cabling, QSFP+ to QSFP+ (40G to 40G) and QSFP+ to 4SFP+ (40G to 10G) breakout cables satisfy customers for various fiber types and reach requirements.

100GbE Fiber Optic Cabling For Future Proofing

With the price of 100G optics cutting down in 2017, 100GbE network is no longer out of customers’ reach. Telecom giants like Cisco, Arista, HPE launches series of 100G optical switches to meet the market demand. And for other 100G components like 100G optical transceivers, fiber patch cables, racks & enclosures, etc, those are ubiquitous on the market.

100G optical transceivers including the CFP, CFP2, CFP4, CXP and the most popular 100G QSFP28 optics in IEEE standards provide a great selection to the overall users.For 100G inter-rack connections, QSFP28 to QSF28 Direct Attach Copper (DAC) Cables and Active Optical Cables (AOC) as well as the QSFP28 to SFP28 breakout cables are the cost-effective solutions.

 

Conclusion

This article introduces 10G/40G/100G fiber optic cabling, and make a clear comparison between the two paths to 100GbE. Customers prefer 4×25Gbps for the reasons: Less parallel paths, less fibers, less optics, less everything. For those who want to upgrade from 40G to 100G, appreciate the reliable performance of 40G with the potential to run across 2 parallel 25Ghz rather than 4 required today.

QSFP28 Transceiver With MTP or LC Duplex Cables

Nowadays, QSFP28 transceiver is the mainstream of 100G optics market. So as to meet different 100G deployment needs, QSFP28 modules usually come in several standards such as QSFP28 PSM4, QSFP28 CWDM4, IR4, SR4 and LR4, etc . Compared with CXP and CFP 100G optical transceivers, QSFP28 optics are the smallest form factors that provide a high-density and high-speed solution for 100G networks. A previous article provide detailed information about what distance QSFP28 optics can support for 100GbE deployment. Today’s article will introduce 100G QSFP28 cabling solutions by the use of MTP/MPO cables and duplex LC cables.

QSFP28 modules offer four channels of high-speed differential signals with each data rates up to 28Gbps, and will meet 100 Gbps (4x25 Gbps) in the end. QSFP28 transceiver is available in 100GBASE-SR4, 100GBASE-LR4, PSM4 and CWDM4 standards. The interface of 100G QSFP28 transceivers includes MTP/MPO and LC duplex cables.

Cabling Solutions of QSFP28 MPO

100G QSFP28 100GBASE-SR4 and 100GBASE-PSM4 transceiver modules are the 100G transceiver modules that need to be connected with MTP/MPO interfaces. 100GBASE-SR4 QSFP28 complies with QSFP28 MSA and IEEE 802.3bm specifications. It can support a link length of 100 m. 100G PSM4 specification defines requirements for a point-to-point 100 Gbps link over eight single-mode fibers with a supporting distance of 500 m. Figure 1 shows the QSFP28 SR4 with MTP connector.

MTP/MPO fiber cable is commonly used to connect QSFP+ or QSFP28 transceivers with single-mode and multimode categories, which is specially designed for 40G/100G high-density data center cabling system. MTP/MPO fiber cables are usually terminated with 12-fiber, 24-fiber, 48-fiber MTP/MPO connectors. Single-mode MTP/MPO cable is able to carry signal over long distance while multimode is for short-reach application. QSFP28 mpo

• 100GBASE-SR4 QSFP28 over Multimode MTP cable

100GBASE-SR4 QSFP28 works over a 12-fiber multimode MTP/MPO patch cable (four not used) for short-reach 100G connection. Figure 2 shows the direct connection between 100GBASE-SR4 QSFP28 modules by the use of Female to Female 12-Fibers OM4 trunk Cable.

• 100GBASE-PSM4 QSFP28 Over Single-mode MTP Cable

Similar to 100GBASE-SR4 QSFP28, 100GBASE-PSM4 QSFP28 also requires 12-fiber MTP/MPO patch cable. But QSFP28 PSM4 matches with single-mode MTP/MPO fiber patch cable instead of the multimode MTP/MPO .patch cables.

100G QSFP28 Optics With Single-mode Duplex LC Interface

100GBASE-CWDM4 QSFP28 and 100GBASE-LR4 QSFP28 are the 100G modules designed for long-reach applications terminated with duplex LC interface. 100GBASE-CWDM4 QSFP28, as the name implies, it is a full duplex module with the use of CWDM technologies. It integrates transmit and receive path in one module. 4 lanes of optical signals (25 Gbps per lane) firstly are multiplexed into an LC duplex interfaces on the transmitting side. Then data streams are de-multiplexed by an integrated optical de-multiplexer and transformed to an electrical CAUI-4 output driver. QSFP28 CWDM4 can support a distance of 2 km over single-mode fibers. Figure 3 shows the interconnection of 100G QSFP28 LR4 module connected with MTP to LC breakout and MTP cassette to achieve a total 400G data rate transmission.

100GBASE-LR4 QSFP28 is a 4x25Gbps transceiver module that can support link lengths up to 10 km. 100GBASE-LR4 QSFP28 also operates over single-mode fiber cable with duplex LC connector by multiplexing and de-multiplexing optical signals. Common single-mode duplex LC patch cable can meet the cabling requirement of these two transceivers. For high density data center, HD LC fiber patch cable is highly recommended as the push-pull tab is easy to remove and can save space.

Conclusion

With compact size and low power consumption, 100G QSFP28 modules are becoming the most popular 100G optics on the market. QSFP28 SR4 and QSFP28 PSM4 transceivers terminate with MTP/MPO interfaces, while QSFP28 LR4 and CWDM4 modules connect with LC duplex cables. Besides QSFP28 transceivers, there are QSFP28 DAC and AOC cable available for short-reach 100G connections.

Can I Use the QSFP+ Optics on the QSFP28 Port?

100G Ethernet will have a larger share of network equipment market in 2017, according to Infonetics Research. But we can’t neglect the fact that 100G technology and relevant optics are still under development. Users who plan to layout 100G network for long-hual infrastructures usually met some problems. For example, currently, the qsfp28 optics on the market can only support up to 10 km (QSFP28 100GBASE-LR4) with WDM technology, which means you have to buy the extra expensive WDM devices. For applications beyond 10km, QSFP28 optical transceivers cannot reach it. Therefore, users have to use 40G QSFP+ optics on 100G switches. But here comes a problem, can I use the QSFP+ optics on the QSFP28 port of the 100G switch? If this is okay, can I use the QSFP28 modules on the QSFP+ port? This article discusses the feasibility of this solution and provides a foundational guidance of how to configure the 100G switches.

For Most Switches, QSFP+ Can Be Used on QSFP28 Port

As we all know that QSFP28 transceivers have the same form factor as the QSFP optical modules. The former has just 4 electrical lanes that can be used as a 4x10GbE, 4x25GbE, while the latter supports 40G ( 4x10G). So from all of this information, a QSFP28 module breaks out into either 4x25G or 4x10G lanes, which depends on the transceiver used. This is the same case with the SFP28 transceivers that accept SFP+ transceivers and run at the lower 10G speed.

A 100G QSFP28 port can generally take either a QSFP+ or QSFP28 optics. If the QSFP28 optics support 25G lanes, then it can operate 4x25G breakout, 2x50G breakout or 1x100G (no breakout). The QSFP+ optic supports 10G lanes, so it can run 4x10GE or 1x40GE. If you use the QSFP transceivers in QSFP28 port, keep in mind that you have both single-mode and multimode (SR/LR) optical transceivers and twinax/AOC options that are available.

In all Cases, QSFP28 Optics Cannot Be Used on QSFP+ Port

SFP+ can’t auto-negotiate to support SFP module, similarly QSFP28 modules can not be used on the QSFP port, either. There is the rule about mixing optical transceivers with different speed—it basically comes down to the optic and the port, vice versa. Both ends of the two modules have to match and form factor needs to match as well. Additionally, port speed needs to be equal or greater than the optic used.

How to Configure 100G Switch

For those who are not familiar with how to do the port configuration, you can have a look at the following part.

• How do you change 100G QSFP ports to support QSFP+ 40GbE transceivers?

Configure the desired speed as 40G:
(config)# interface Ethernet1/1
(config-if-Et1/1)# speed forced 40gfull

• How do you change 100G QSFP ports to support 4x10GbE mode using a QSFP+ transceiver?

Configure the desired speed as 10G:
(config)# interface Ethernet1/1 - 4
(config-if-Et1/1-4)# speed forced 10000full

• How do you change 100G QSFP ports from 100GbE mode to 4x25G mode?

Configure the desired speed as 25G:
(config)# interface Ethernet1/1 - 4
(config-if-Et1/1-4)# speed forced 25gfull

• How do you change 100G QSFP ports back to the default mode?

Configure the port to default mode:
(config)# interface Ethernet1/1-4
(config-if-Et1/1)# no speed

Note that if you have no experience in port configuration, it is advisable for you to consult your switch vendor in advance.

Conclusion

To sum up, QSFP+ modules can be used on the QSFP28 ports, but QSFP28 transceivers cannot transmit 100Gbps on the QSFP+ port. When using the QSFP optics on the QSFP28 port, don’t forget to configure your switch (follow the above instructions). To make sure the smooth network transmission, you need to ensure the connectors on both ends are the same and no manufacturer compatibility issue exists.

Original source : http://www.chinacablesbuy.com/can-use-qsfp-optics-qsfp28-port.html

Stay For 40Gbps Network or Scale Up to 100G?

The evolution of bandwidth for data transmission is unstoppable. From the 10Mbps, 100Mbps Ethernet to the 10G or 40/100G Ethernet, telecom manufacturers keep promoting higher internet speed to facilitate people’s daily life. Now, bandwidth speeds of 1Gbps to 10Gbps Ethernet capacity are commonly utilized around the world. However, with the increase in data center and cloud computing technologies, the demand for bandwidth speeds of 40G to 100G Ethernet is growing steadily for carriers and other data consumers.

Just like the dilemma of whether to use the fiber optic cable for high performance or adopt copper cable for the low cost, these high-end data consumers also have the doubt about 40G and 100G. Should we upgrade our capacity to 40Gbps or skip 40Gbpsand migrate directly to 100Gbps Ethernet? This article will help to draw an answer to this dilemma from the aspects of market trend for required bandwidth, cost and performance.

Upgrade Straight to 100G

According to today’s market trend, the tendency is to skip 40Gbps. With demanding users peeling off multiple 10Gbps channels, the 40Gbps pipe becomes quickly utilized. Carriers scaling up to 100Gbps, allows greater flexibility for one’s network infrastructure utilizing multiplexing solutions to carve multiple bandwidth channels from a single pipe. On another scale, the same is true for the consumer market where capacity is increasing from 1Gbps to 10Gbps, skipping 2.5Gbps levels, due to the flexibility and scalability 10Gbps provides at a very similar cost. In many cases, carriers and consumers have decided to skip 40Gbps and acquire 100Gbps for the following reasons and benefits:

• Cost Efficiency—From a network equipment standpoint, often it may be more cost-efficient to upgrade a 10Gbps link to 100Gbps, versus 40Gbps. Essentially, if you should require 60Gbps or say even 80Gbps, additional cards would be needed to support the link in the chassis, whereas a customer may utilize only one card to achieve more than twice the bandwidth at 100Gbps. 100Gbps allows the network to operate within a smaller footprint of a data center, which in turn, reduces power consumption dissipating less heat and thus lower operational costs.
• Lower Latency—100Gbps provides lower latency capabilities than 40Gbps; many carrier grade vendors are lowering latency on 100Gbps matching latency of traditional 10Gbps traffic.
• Flexibility—Creates options to provide multiple variations of delivery with handoffs ranging from 10Gbps, 40Gbps or the full 100Gbps pipes.
• Scalability—Although a customer may not utilize 100Gbps on day one, the ability is there to scale the network with no forklift upgrade at any point, future-proofing the solution well beyond capacity needs.

As consumer’s demands for higher bandwidth continues to rise, many equipment suppliers, who developed some of the first 100 Gigabit Ethernet Router Interfaces, are now working on developing 200Gbps, 400Gbps up to 1 Terabyte interfaces.

This article is not implying that there is no use for 40Gbqs bandwidth level technology. Instead, I suggest that many end consumers are looking to keep up with the acceleration of high bandwidth demands while maintaining the efficiency and technologies needed to support their network infrastructure requirements while reducing operating costs.

100G Optic Solutions

FS.COM 100G transceiver solution offers customers 100 Gigabit Ethernet connectivity options for data center networking, enterprise core aggregation, and service provider transport applications. Various of 100G transceivers including CXP, CFP, CFP2, CFP4 and QSFP28 are available for different applications. The following part will lists two cost-effective 100G solutions.

• QSFP28 to QSFP28 Interconnection

The QSFP28 is the exact same footprint as the 40G QSFP+, but is implemented with four 25Gbps lanes. To interconnect a multimode QSFP28 link, a 12-fiber MPO/MTP patch cable is required, while for single-mode link (100GBASE-LR4 QSFP28), a duplex LC single-mode patch cable is required. The interconnection of QSFP28 multimode link is similar with the case of QSFP28-100G-SR4 see in the following figure.

• CXP/CFP to CXP/CFP Interconnection

FS.COM’s 24-fiber MPO/MTP assemblies are ideal for 100GBASE-SR10 CXP/CFP to CXP/CFP interconnection in data center, since it is implemented 10 lanes of 10 Gbps. Among the 24 fibers, only 20 fibers in the middle of the connector are used to transmit and receive at 10 Gbps and the 2 top and bottom fibers on the left and right are unused. The following picture shows the interconnection between two 100GBASE-SR10 CXP ports.

FS.COM provides a full selection of 100G optics including CFP, CFP2, CFP4, QSFP28 (QSFP28-100G-SR4) and QSFP28 DAC cables just as listed above. All of our products are fully compatible with the original brand. In addition, our 100G transceivers offer significant advantages over existing solutions in terms of reduced power dissipation and increased density with the added benefit of pluggability for reduced first installed cost. If you have any requirement, you can send your request to us.

Are You Ready for Embracing 100G Ethernet?

Ethernet as the networking standards, enables computers to locally connect to each other, which is the ultra-strong backbone to the many networks we use every day. Although most of the Ethernet market is still running around 1 Gbqs or 10 Gbqs, there is a strong interest in higher data rates. Many hardware vendors like Cisco, Finisar, Huawei and Brocade have recently announced support for 100 Gigabit Ethernet and telecom vendors around the world have also shown interest in launching 100G networks. All these events shows the sign of the advent of 100 Gigabit Ethernet in the commercial segment. However, is it necessary to move to 100G now? Or should the 100g migration be a smooth one just as the IEEE has made when moving to 40G? This article will highlight the reasons and solutions of upgrading to 100G.

Why Move to 100G?

• Most enterprises today are encouraging telecommuting and promote real-time, high-definition, high-quality voice and video solutions. All these require a huge bandwidth capacity. Additionally, 100G implementations offer an effective means to operate seamlessly within an existing 10G network infrastructure, avoid the need for additional optical amplifiers, dispersion compensators or regenerators. 100G is today’s choice to scale networks in a way that delivers the required capacity in the most efficient manner, readying the network for tomorrow’s bandwidth crunch.
• Another interesting point is the efficiency of 100G Ethernet compared to link aggregation that is used today. As of now, a 10 x 10G Ethernet link aggregation can not give a throughput of up to 100 Gbps. This limitation can be overcome with a true 100G connection which can give a 100Gbps bandwidth, thus allowing high capacity links to scale even further. Considering all these, if not this year or the next, 100G will be widely adopted soon.
• Last but not the least, the industry have come together in order to create a healthy 100G ecosystem, which will be beneficial for the entire community. This broad inclusion will result in a fast introduction of 100G solutions that will meet industry performance, size, cost, and power requirements. If the cost drive is right, once 100G is standardized and commercially available, network operators will quickly capitalize 40G investments and adopt 100G transmission for their future deployments.

Migrate to 100G with 100G Transceiver Modules

There are several form factors for supporting 100GbE including CFP, CFP2, CFP4, QSFP28 and CPAK. The following will make a clear introduction to all of them.

CFP Transceiver

The CFP is the very first 100G transceiver for the transmission of high-speed digital signals, the C stands for the Latin letter centum (means 100). The CFP module was designed after the SFP interface, but is significantly larger to support 100 Gbqs using 10 x 10 Gbit/s lanes in each direction (RX, TX). The optical connection can support both 10 x 10 Gbit/s and 4 x 25 Gbit/s variants of 100 Gbit/s interconnects. There are four common types of CFP transceiver modules, such as 100GBASE-SR10 in 100 meter MMF, 100GBASE-LR10 and 100GBASE-LR4 in 10 km SMF reach, and 100GBASE-ER10 and 100GBASE-ER4 in 40 km SMF reach respectively.

As improvements in technology have allowed higher performance and higher density, which drives the development of the CFP2 and CFP4 specifications. While CFP, CFP2 and CFP4 are electrical similar, they specify a form-factor of 1/2 and 1/4 respectively in size of the original specification. Note that CFP, CFP2 and CFP4 modules are not interchangeable, but would be inter-operable at the optical interface with appropriate connectors.

QSFP28 Transceiver

QSFP28 is the same footprint as the 40G QSFP+ module. Just as the 40G QSFP+ module is using four 10Gbps lanes, the 100G QSFP28 is implemented with four 25Gbps lanes. In all QSFP versions, both the electrical lanes and the optical lanes operate at the same speed, eliminating the costly gearbox found in CFP, CFP2, and the CPAK. The QSFP28 module has an upgraded electrical interface to support signaling up to 28Gbps signals, yet keeps all of the physical dimensions of its predecessor. As QSFP28 technology becomes even maturer, QSFP28 transceivers will become more and more popular in 100G optics market. The above image shows a QSFP-100G-SR4-S. it is Cisco 100GBASE-SR4 QSFP28 transceiver module.

100GBASE-SR4 QSFP28 transceiver and 100GBASE-LR4 QSFP28 transceiver are the two main types of the QSFP28 transceivers. The former is specified to operate over multimode fiber (MMF) with the maximum link length of 70m on OM3 and 100m on OM4, while 100GBASE-LR4 QSFP28 is standardized to work through single-mode fiber (SMF), able to realize 10km link length.

QSFP28 vs. CFP

QSFP28 and CFP are the two common 100G optical transceivers available on the market. As noted before, CFP is the first-generation 100G transceiver. It is the common scene that QSFP28 makes an appearance and CFP takes a bow, which reflects the trend in the industry to aggressively bring 100GE density up and costs down. CFP4 is half the width of CFP2, which is half again the width of CFP. QSFP28 has the same footprint and faceplate density as QSFP+ and is just slightly smaller than CFP4. Theoretically, QSFP28 seems to have the density advantage over CFP4, but CFP4’s higher maximum power consumption gives it the advantage on longer reach optical distances. However, the CFP is much more expensive than QSFP28 and will not be used for lower speeds because of the high cost.

CPAK Transceiver

CPAK is another newcomer to supporting 100G network. This is a proprietary form factor from Cisco but the interfaces demonstrated are IEEE standards and will interoperate with the same interfaces supported by other form-factors. Together, these solutions will deliver the smallest form-factor, most efficient 100-Gbps optical transceiver portfolio in the industry. Cisco CPAK will be available in several IEEE-standard optical interfaces.

Conclusion

Within the next several years, 100G is doom to become the dominant backbone technology in terms of its high capacity over 10G and surpassing would-be high-speed contender 40G. Of course, we must count on the components and systems suppliers to build products that meet technical and economic requirements while allowing a smooth migration to the 100G infrastructure that is being put in operation today. Fiberstore as a rising telecom supplier, is committed to promote telecommunication development. We recently release a full range of 100G optical transceivers including CFP, CFP2, CFP4, QSFP28 and QSFP28 DAC cables. All of our products are fully compatible with the original brand. If you have any requirement, you can send your request to us.

Upcoming 40/100G Technology

The past decades witnessed the tremendous advancement in Ethernet network transmission speeds from 10/100 base systems to 1G then 10G deployments. Today, 10G server uplinks are ubiquitous in the data center, driven by the need for higher bandwidth, 40/100G server uplinks are just around the corner. IEEE ratified 40/100G Ethernet Standard in June 2010. Since then people were hoping to embracing this new Gigabit Ethernet. However, migrating to higher data rates seems not be that easy. This article will pay special attention to those aspects that influence the migration path.

New Transceiver Interface: MPO Connector
When transition to 40/100G, parallel optics are needed to transmit and receive signals. Because for 40G, there are 4-Tx and 4-Rx fibers, each transmitting at 10G for an aggregate signal of 40G. And for 100G, there are 10-Tx and 10-Rx. As parallel optics technology requires data transmission across multiple fibers simultaneously, a multifiber (or array) connector is required. Defined by TIA-604- 5-C, Fiber Optic Connector Intermateability Standard, MPO (FOCIS-5) is an array connector that can support up to 72 optical fiber connections in a single connection and ferrule. Factory-terminated MPO solutions allow connectivity to be achieved through a simple plug and play system. And this MPO-terminated backbone/horizontal cabling is simply installed into preterminated modules, panels, or Harnesses.

40G Ethernet Solution
According to IEEE 802.3ba, 40G was designated to support high-performance computing clusters, blade servers, SANs and network-attached storage. When deploying 40G network, QSFP transceiver and a 12-fiber MPO will be utilized. Deployment of 40G over multimode fiber will be achieved with 4-Tx and 4-Rx fibers from the 12-fiber MPO. The fibers will be the outer fibers as shown in Figure 3. Each of these four “channels” will transmit 10G for the combined 40G transmission. While single-mode fiber transmission will remain duplex connectivity using course wavelength division multiplexing. Some transmission media for 40G are to be included in the following table.

• 40 GBASE-SR4 (parallel optics)

—100m on OM3/125m on OM4, 10G on four fibers per direction

• 40 GBASE-LR4 course wavelength division multiplexing (cWDM)

—10km on single-mode fiber, 4x 10G 1300 nm wavelength region like QSFP-40GE-LR4

• 40 GBASE-CR4

—7 m over copper, 4 x 10G (twinax copper)

100G Ethernet Solution
40G is to support increasing bandwidth demand for server computing, while 100G was designated to support switching, routing and aggregation in the core network. For 100G deployments, the CXP will be the electronics interface for OM3/OM4 multimode fiber, while CFP will be the interface for single-mode fiber. For 100G transmission over multimode fiber, the optical connector interface will be the 24-fiber MPO connector that will support 10-Tx and 10-Rx channels, each transmitting at 10G. Transmission over single-mode will be achieved via wavelength division multiplexing with duplex connectivity.

• 100 GBASE-SR10 (parallel optics)

—100m on OM3 or 125m on OM4, 10G on 10 fibers per direction

• 100 GBASE-LR4 (dWDM)

—10km on single-mode, 4 x 25G 1300 nm

• 100 GBASE-ER4 (dWDM)

—40km on single-mode, 4 x 25G 1300 nm

• 100 GBASE-CR10

—7 m over copper, 10 x 10G (twinax copper)

Cabling Migration From 10G to 40G to 100G in an MPO-based System
Starting with 10G, a 12-fiber MPO cable is deployed between the two 10G switches. Modules are used at the end to transition from the 12-fiber MPO to LC duplex. This enables connectivity into the switch (Figure 3).

For 12-fiber MPO cassette-based optical systems already installed, 40G migration is as simple as replacing the existing cassette from the patch panel housings at the equipment and cross connects with an MPO adapter panel. The use of a 12-fiber MPO jumper is needed to establish connectivity between the switches (Figure 4).

Future 100G networks will require a 24-fiber MPO jumper to establish a link. Systems that use 12-fiber MPO backbone cabling will need a 24-fiber to two 12-fiber MPO jumpers (Figure 5).

Future Proofing
As we transition to 40G and 100G, an MPO-based trunk with appropriate fiber can be installed, which will provide an easy migration path to future higher-speed technology. This article has mentioned some optical devices and cabling solutions to support 40/100G Ethernet. Fiberstore provides a large amount of 40/100G equipment like 40G QSFP+ (JG661A), 40G DAC and AOC, etc. CFP, CFP2, CFP4 and QSFP28 are also offered with very competitive prices and high quality. To best meet the needs of the future, future proofing is crucial. So if you have any requirement of our products, please send your inquiry to 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.

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.

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.

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.

Reference:
http://www.panduit.com/heiler/TechnologyBriefs/D-COTB02--WW-ENG-25GigEthernet4Servers-W.pdf

SFP28 and QSFP28 Optical Modules For 25 Gigabit Ethernet

The widely acknowledged Ethernet speed upgrade path was 10G-40G-100G. However, a new development indicates the latest path for server connection will be 10G-25G-100G with potential for future upgrading to 400G. But why 25G? Because moving from 10G to 40G is a big jump and it turns out the incremental cost of 25G silicon over 10G is not that great. This new standard will require improved cables and transceiver modules capable of handling this additional bandwidth, under this circumstance, QSFP28 and SFP28 are promoted.

25GbE Ethernet—An Emerging Standard
25 Gigabit Ethernet (25GbE) 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. 25GbE leverages technology defined for 100 Gigabit Ethernet implemented as four 25-Gbit/s lanes (IEEE 802.3bj) running on four fibers or copper pairs. The follow picture shows 25G Access Network.

Significant Performance Benefits—25G Over 40G
The value of 25GbE technology is clear in comparison to the existing 40GbE standard. Obviously, 25GbE technology provides greater port density and a lower cost per unit of bandwidth for rack server connectivity. For applications that demand substantially higher throughputs to the endpoint, there exists 50GbE—using only two lanes instead of four—as a superior alternative to 40GbE in both link performance and physical lane efficiency.

The proposed 25GbE standard delivers 2.5 times more performance per SerDes lane using twinax copper wire than that available over existing 10G and 40G connections. A 50GbE link using two switch/NIC SerDes lanes running at 25 Gb/s each delivers 25% more bandwidth than a 40GbE link while needing just half the number (four) of twinax copper pairs. Therefore, a 25GbE link using a single switch/NIC SerDes lane provides 2.5 times the bandwidth of a 10GbE link over the same number of twinax copper pairs are used in today’s SFP+ direct-attach copper (DAC) cables.

Perhaps the most important benefit of 25GbE technology to data-center operators is maximizing bandwidth and port density within the space constraints of a small 1U front panel. It also leverages single-lane 25Gb/s physical layer technology developed to support 100GbE.

Cloud Will Drive to QSFP28 and SFP28
QSFP28 is used for 4x25GE and SFP28 is used for a single 25GE port. SFP28 module, based on the SFP+ form-factor, suports the emeraging 25G Ethernet standard. It enables error-free transmission of 25Gb/s over 100m of OM4 multi-mode fiber and a new generation of high-density 25 Gigabit Ethernet switches and network interface cards, facilitating server connectivity in data centres, and a conventional and cost-effective upgrade path for enterprises deploying 10 Gigabit Ethernet links today in the ubiquitous SFP+ form factor.

The QSFP28 (25G Quad Small Form-Factor Pluggable) transceiver and interconnect cable is a high-density, high-speed product soluon designed for applicaons in the telecommunicaons, data center and networking markets. The interconnect offers four channels of high-speed signals with data rates ranging from 25 Gbps up to potentially 40 Gbps, and will meet 100 Gbps Ethernet (4x25 Gbps) and 100 Gbps 4X InfiniBand Enhanced Data Rate (EDR) requirements.

The demonstration showed QSFP28-SR4 modules and a compatible Finisar FTLX1471D3BCL 10GBASE-LR SFP+. The QSFP28 SR4 module is a vertically integrated solution that meets IEEE 802.3 standards and MSA requirements with power dissipation well under 3.5W. The module supports both 100GBASE-SR4 as well as 4x25G breakout applications. Both the QSFP28 SR4 and SFP28-SR modules are sampling now.

Conclusion
The dominant next-generation server connection speed is going to be 25G as it providing a cost competitive longer reach option for mainstream customers. Fiberstore is excited to introduce several products that will drive the next generation of data centre and enterprise interconnects. We currently do not supply 100G QSFP28 and 25G SFP28 based switches, but we do manufacture a full range of tranceivers, such as SFP+, X2, XENPAK, XFP, SFP, GBIC, CWDM/DWDM, 40G QSFP+ & CFP, etc. Compatible Finisar FTLX1471D3BCL and FTLF8524P2BNL are offered with minimum price and high quality. If you are interested, please feel free to contact us.

Reference:
http://www.ieee802.org/3/cfi/0714_1/CFI_01_0714.pdf