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What Is SFP Connector, SFP+ Connector and SFP28 Connector?

SFP (Small Form-factor Pluggable) module connector with various data speed rate is one of the major optical transceivers used for data communication. With ever-increasing demand for faster speed and higher density, the SFP connectors have experienced several generations of update for the signal speed capability as well as port density, from the original SFP to SFP+ and then to the new SFP28 type. The compatibility of these connecting ports is the pain point for many subscribers in data communication transmission. So what’s the similarities and differences between them and are these module connectors compatible with each other when plugged into switches? SFP28 vs SFP+ vs SFP connector, which one should you choose? This paper will give you the answer.

What Is SFP Connector?

Specified by a multi-source agreement (MSA), SFP connector was first introduced in early 2000 and designed to replace the previous gigabit interface converter (GBIC) connector in fiber optic and Ethernet high-speed networking systems. Based on the IEEE 802.3, SFF-8472 protocol specification, SFP module connectors has the ability to handle up to 4.25Gb/s with greater port density than the GBIC, which is why SFP is also known as mini GBIC. This allowed it to quickly become the connector of choice for system administrators who liked the idea of being able to significantly increase their output per rack. The SFP connectors can support Gigabit Ethernet, Fibre Channel, Synchronous Optical Network (SONET) and other communication standards.

What Is SFP+ Connector?

To cater the need for faster transmission speed, the SFP+ (or SFP10) was introduced in 2006, as an extension of the SFP connector. Based on IEEE802.3ae, SFF-8431, and SFF-8432 protocol specifications, the SFP+ is designed to support data rates up to 10Gb/s. Compared with its predecessor SFP, the newly SFP+ can support Fibre Channel, 10GbE, SONET, OTN, and other communication standards. The SFP+ is similar in size to the SFP connector. And the primary difference between an SFP and a SFP+ is their transmission speed. It is noticeable that SFP/SFP+ are both copper and optical.

SFP Connector

SFP28 Connector–The Third Generation of SFP Connector

As the third generation of SFP interconnect systems, the SFP28 (Small Form-Factor Pluggable 28) is designed for 25G performance specified by the IEEE 802.3by. The SFP28 connector delivers increased bandwidth, superior impedance control with less crosstalk compared to the SFP10. SFP28 can be sorted into SFP28 SFP-25G-SR and SFP-25G-LR. The former is designed to transfer data over short distance (up to 100m over MMF) while the latter is suitable for long distance transmission (up to 10 km over SMF). Utilizing 25GbE SFP28 leads to a single-lane connection similar to existing 10GbE technology, however it can deliver 2.5 times more data, which enables network bandwidth to be cost-effectively scaled in support of next-generation server and storage solutions.

Are the SFP, SFP+ and SFP28 Products Backward Compatible?

In most cases the connector and cable assembly are all backward compatible – an SFP+ connector is a direct replacement for an SFP connector to ensure simple upgrade to customer systems. As these are standard products, the cable assembly will also be compatible between the systems – an SFP copper cable assembly can be inserted to an SFP+ cage and mate with a SFP+ connector on the board.

Then how about the new SFP28 product? Since transceivers with various SFP connector types have become an important constituent of data communication network, compatibility issue of SFP28 and SFP+ is controversial among many subscribers. Here is a typical topic from Reddit, and it says like “For a project we’re looking to purchase some nexus 93180YC-EX ToRs for 25Gb+ down to the compute nodes. Cisco states that the downlink 25Gb ports are also 10Gb capable, but one can only really assume that means that the port is compatible with SFP+ optics too. Cisco’s SFP+ compatibility matrix appears to support that claim, however just curious if any of you have any SFP28 experience yet to confirm?”

The answer is definitely “yes”. SFP28 adopts the same form factor as SFP+, just running at 25 Gb/s instead of 10Gb/s, which offers better performance and higher speed. Besides, the pinouts of SFP28 and SFP+ connectors are mating compatible. Therefore, SFP28 connector is backwards compatible with SFP+ ports. That is to say, an SFP28 can be plugged into an SFP+ port and vice versa, but plugging an SFP+ into an SFP28 port would not get you 25Gb/s data rates.

Conclusion

SFP28 vs SFP+ vs SFP connector? Have you made clear which one to choose? Whether choosing SFP or SFP+ depends on your switch types. If your switch port only supports 1G, you can only choose the 1000BASE SFP (eg.MGBSX1). If it is a 10G switch, it depends on the speed and distance you require. When choosing between SFP28 and SFP+, it all depends on the transmission data rates you need. The SFP28 aims to build 25GbE networks that enables equipment designers to significantly reduce the required number of switches and cables. Thus when considering reduced facility costs related to space, power and cooling, the SFP28 would be the optimal choice for you.

Data Centers: Say Hello to White Box Switch

Today, nearly all mainstream organizations use traditional (integrated) switches from vendors like Cisco, HP, Arista and Juniper. However, hyperscale folks such as Google, Amazon and Facebook are taking the lead to use white box switch in the portion of their networks, operating the system in a different manner. So what is the magic behind that? Are these OTTs the only customers of white box switch? You may find some hints in this article.

White Box Switch

What Makes White Box Switch Special?
White box switches consists of generic and inexpensive hardware and a preload network operating system (NOS) that can be purchased and installed separately. Often the hardware and software come from different vendors. This is in contrast to a traditional switch that comes as one package including the hardware and the software. For example, when you buy a catalyst switch from Cisco, you are obliged to use Cisco IOS as its operating system. But with white box switch, you are allowed to buy hardware and software separately.

Except offering increased software flexibility/programmability and reduced vendor lock-in, white box switch enables users to have multiple choices on hardware, network operating system (NOS) and applications. The impact of which is profound when it comes to network orchestration, routing, automation, monitoring and network overlay.
White Box Switch NOS

What About the Target Market of White Box Switch?
White box switch is initially designed for data centers. Companies that operating mega data centers are especially prefer white box switch for at least two reasons: these companies generally demand for massive deployment of switches and the port density of each switch needs to be high. White boxes are cheaper while offering high-density ports, hence proven to be an optimal alternative. On the other hand, these large-scale companies also value the flexibility and openness of the switch platform, besides CAPEX savings. As an open platform to offer broader flexibility, white box switch free them from traditional L2/L3 protocols, enabling more possibilities to develop and support any SDN based networking.

So, are these large-scale OTTs the only target market for the white box switch? Definitely No!

Any small or medium-sized cloud based providers, or data center of service providers can consider deploy white box switches in data centers, concerning the cost savings and enhanced flexibilities compared with traditional switches. Also because of the familiar IT tools/ commands their technicians are used to. However, white box switches are not yet ready to offer all features and services that a service provider needs to offer, and not yet for deployment in non data center environments.

The Potential of White Box Switch
Based on an open platform, white box switch offers greater possibilities for innovation when compared with traditional networking gears. As the number of vendors that specialized in developing software began to soar, customers can choose from a range of software solutions with added functionality and reduced price.

White box switch becomes even popular in this age of SDN. In traditional switches, software and hardware are integrated into one package, which limits the network innovation greatly. SDN is here to decouple the software from hardware, helping speed shifts in networking. It resembles the standpoint of white box switching. Moreover, the advert of SDN also drives white box forward: when combined with SDN-centric designs, these deployments have resulted in dramatic improvements in automation, operational simplification, and faster innovation. These benefits are now being realized by enterprises of all sizes via commercially available SDN solutions.

Conclusion
Despite the fact that white box switches cannot be applied in non-data center environment for the time being, they are meeting their target market requirements successfully. The potential of white box switch cannot easily be underestimate, it is an ideal alternative that worth to be seriously considered at least for data center applications.

How to Build DWDM Network Over CWDM Network

Using CWDM MUX/DEMUX has been widely accepted as the most cost-effective and time-save method to increase the existing fiber optic network without adding optical fibers. However, a CWDM network can only support up to 18 different wavelengths. Is there any possibility to increase the capacity of the existing CWDM network? Hybrid CWDM and DWDM network is being introduced to combine the DWDM wavelengths with the existing CWDM wavelengths.

Combing DWDM With CWDM to Increase Network Capacity

As we know the CWDM wavelengths ranging from 1260nm-1625nm with space channel of 20nm actually cover all the range of DWDM wavelengths (ranging from 1470nm to 1625nm). However, DWDM wavelengths have much smaller channel spaces (0.4nm/0.8nm/1.6nm) and can provide larger bandwidth than that of the CWDM wavelengths. To combine DWDM with CWDM, the CWDM wavelengths that are near DWDM wavelengths can be used to transmit the DWDM wavelengths. However, not all these CWDM wavelengths are suggested. Generally, wavelengths of 1530nm and 1550nm are used to combine the CWDM and DWDM network together. Similarly, not all the DWDM wavelengths are suggested to be combined with CWDM network. The following picture shows DWDM wavelengths that are suggested to be combined with 1530nm and 1550nm.

CWDM DWDM hybrid wavelengths

How to connect CWDM With DWDM

To combine the DWDM wavelengths with CWDM wavelengths, both CWDM MUX/DEMUX and DWDM MUX/DEMUXs should be used. The following picture shows the connection methods for hybrid CWDM and DWDM. On both ends of the fiber link, a CWDM MUX/DEMUX and a DWDM MUX/DEMUX with corresponding wavelengths are deployed. Connect the line port of the DWDM MUX/DEMUX to the 1530nm/1550nm channel port of the CWDM MUX/DEMUX, the DWDM wavelengths can be added to the existing CWDM network.

DWDM over CWDM

Easier Operation and Cabling Solution for Hybrid CWDM and DWDM

In the CWDM and DWDM Hybrid network, the CWDM MUX/DEMUX and DWDM MUX/DEMUX play the most important roles. To offer better operation and cabling environment for these WDM MUX/DEMUX, FMU series products which are developed by FS.COM has been introduced. This series of products combines the MUX/DEMUX into half-U plug-in modules, and installed in 1U rack for better cable management and network operation as shown in the following picture.

FMU DWDM over CWDM solution

For CWDM and DWDM hybrid network, a FMU CWDM MUX/DEMUX and a DWDM half-U plug-in module can be installed together in a FMU 1U rack chassis. Thus, the two modules can be linked together easily. Meanwhile, with clear port identification, the management and operation of the fiber optic network would be easier.

Conclusion

The CWDM network can be added with DWDM wavelengths by the using of CWDM MUX/DEMUX and DWDM MUX/DEMUX which support corresponding wavelengths. The DWDM wavelengths that are 6.5nm around 1530nm and 1550nm are suggested to be used for CWDM and DWDM hybrid network. For better network operation and cabling, FMU series WDM solutions are suggested, which can provide easier and more flexible connections between CWDM MUX/DEMUX and DWDM MUX/DEMUX. Kindly contact sales@fs.com for more details about DWDM over CWDM solution, if you are interested.

Source: How to Achieve DWDM Over CWDM

What 2016 Optical Interconnection Hardware Market Will Be Like?

2016 optical interconnection hardware market trend

2015 is a harvest year to many vendors in optical communication. According to the research “Optical Network Hardware Tracker” by IHS, the global optical network market has increased 3 percent to $ 12.5 billion in 2015. Even, optical interconnection hardware market, which usually has the most fierce competition, also increased in 2015 driven by the whole industry. Will this tendency be kept in 2016 for optical interconnection hardware market?

Needs Drive the Market

Firstly, the insight of optical interconnection hardware market in last year should be given. In 2015, optical growth is greatly driven by the increasing needs for higher Ethernet speed. This is because the application of advanced technologies like Cloud, Internet of Things, and virtual data center. In addition, the deployment of projects like FTTH (fiber to the home) and 4G network also promoted the optical interconnection hardware market. It is clear that these applications and projects will still be the largest driver of the optical interconnect market in 2016. The most possible trends of optical interconnection hardware market could be concluded by three keywords: high speed, compatible and high density.

High Speed—Breakout Year of 100G

High speed is one of the keywords of this industry, and for 2016, it still plays an important role. It is clearly proved by the market needs that higher Ethernet speed is the irresistible trend. Although not many data centers have taken the lead to migration to 40/100G, the 40G and 100G will be the key growth segment of the market in the next few years according to the research by IHS. As shown in the following picture, the 100G market is predicted to grow 262 percent from 2015 to 2016. Inspecting the 2015 market signals, 2016 might be the breakout year of 100G. Fiberstore as the leading provider in optical communication has already launched 100G interconnection products including 100G transceiver and DAC (direct attached cable).

IHS global network market prediction

Compatible—More Economical Choices for Customers

An important reason why so many data centers and enterprise networks slow down the 40/100G migration plan, is the cost. For example, almost every data center needs optical transceivers and DAC for interconnection. And these products must be compatible from the switches. However, the switch market has already been monopolized by large vendors like Cisco. And the original brand 100G optical transceivers and DACs are usually very expensive. Luckily, vendors like Fiberstore can provide full series optical transceivers with a lifetime warranty, fully compatible with networking kit. What’s more these products are much cheaper than the original brand ones and have the same performance. These third party transceivers offer customers more choices with lower prices, which is very likely to promote the optical interconnection market, especially, for 100G products.

High Density—Urgent Problem

High Ethernet speed means more devices and cables should be deployed in data center where the space is usually limited. Enlarging the size of a data center is a good method, however, it will cost a lot. Except the investment for more room, the invest for maintenance and cooling also cannot be ignored. Thus, increasing the port and cabling density would be the most economical and effective way for most data centers. In the past years, small form factor optics, high density network rack system and MPO products are applied to increase the cabling and port density. In 2016, Fiberstore innovatively provides high density LC and MPO patch cords with push-pull tabs which can increase the cabling density and flexibility effectively for optical interconnection.

Facing the Competition

High speed, compatible, and high density three most obvious trends of 2016 optical interconnection hardware market. With the driver of the market needs, the market is very likely to keep the tendency of 2015. Growth of 100G interconnection products is predicted to be a key growth segment in 2016. However, where there is market there is competition. Seen the market signals, more vendors will join the competition of optical interconnection hardware market. By providing fully tested products and the most reasonable price of optical interconnection products, Fiberstore is ready and willing to face the challenges and opportunities in 2016.

Drop Cable and Its Termination in FTTH

FTTH (fiber to the home) networks are installed in many areas covering indoor section, outdoor section, as well as the transition in between. To fulfill the cabling requirements from different areas, different types of fiber optic cables are well developed. Drop cable as an important part of FTTH network forms the final external link between the subscriber and the feeder cable. This blog post will focus on this special outdoor fiber optic cable.

The Basic of FTTH Drop Cable

Drop cables, as previously mentioned, are located on the subscriber end to connect the terminal of a distribution cable to a subscriber’s premises. They are typicality small diameter, low fiber count cables with limited unsupported span lengths, which can be installed aerially, underground or buried. As it is used in outdoor, drop cable shall have a minimum pull strength of 1335 Newtons according to the industry standard. Drop cables are available in many different types. The following part introduces three most commonly used drop cables divided according to the cable structure.

Flat Type Drop Cable, also known as flat drop cable, with a flat out-looking, usually consists of a polyethylene jacket, several fibers and two dielectric strength members to give high crush resistance. Drop cable usually contains one or two fibers, however, drop cable with fiber counts up to 12 or more is also available now. The following picture shows the cross section of a flat drop cable with 2 fibers.

flat drop cable

Figure-8 Aerial Drop Cable is self-supporting cable, with the cable fixed to a steel wire, designed for easy and economical aerial installation for outdoor applications. This type of drop cable is fixed to a steel wire as showed in the following picture. Typical fiber counts of figure-8 Drop Cable are 2 to 48. Tensile load is typically 6000 Newtons.

Figure-8 Aerial Drop Cable

Round Drop Cable usually contains a single bend-insensitive fiber buffered and surrounded by dielectric strength members and an outer jacket, which can provide durability and reliability in the drop segment of the network. The following shows the cross section of a round drop cable with one tight buffered optical fiber.

round drop cable

Drop Cable Connectivity Method: Splice or Connector?

It’s necessary to choose a right architecture for FTTH network from overall. However, drop cable as the final connection from the fiber optic network to customer premises also plays an important role. Thus, finding a flexible, efficient and economical drop cable connectivity method becomes a crucial part of broadband service. Whether to use a fiber optic connector, which can be easily mated and un-mated by hand or a splice, which is a permanent joint? The following will offer the answer and the solutions for your applications.

It is known that splice, which eliminates the possibility of the connection point becoming damaged or dirty with a permanent joint, has better optical performance than fiber optic connector. However, splice lack of operational flexibility compared with fiber optic connector. Fiber optic connector can provide an access point for networking testing which cannot be provided by splicing. Both methods have their own pros and cons.

Generally, splice is recommended for drop cables in the places where no future fiber rearrangement is necessary, like a greenfield, new construction application where the service provider can easily install all of the drop cables. Fiber optic connector is appropriate for applications which flexibility is required, like ONTs which have a connector interface.

Choosing the Right Splice Method

For splice, there are two methods, one is fusion splicing, the other is mechanical splicing. Fusion splicers have been proved to provide a high quality splice with low insertion loss and reflection. However, the initial capital expenditures, maintenance costs and slow installation speed of fusion splicing hinder its status as the preferred solution in many cases. Mechanical splicing are widely used in FTTH drop cable installation in countries, as a mechanical splice can be finished in the field by hand using simple hand tools and cheap mechanical splicer (showed in the following picture) within 2 minutes. It’s a commonly used method in many places, like China, Japan and Korea. However, in US mechanical splicing is not popular.

FTTH Drop Cable Mechanical Splicer

Choosing the Right Connector

For fiber optic connector, there are two types connector for drop cable connection. Field terminated connector, which contains fuse-on connector and mechanical connector, and pre-terminated drop cable, which is factory terminated with connector on the end of drop cable.

Fuse-on connector uses the same technology as fusion splicing to provide the high optical connection performance. However, it requires expensive equipment and highly trained technician, and more time like fusion splicing. Mechanical connector could be a replacement of fuse-on connector (showed in the following picture), if the conditions do not fit the mentioned ones. It could be a time-save and cost-save solution for drop cable termination.

fuse-on connector

If you have no limits in cost and want high performance termination in a time-save way, pre-terminated drop cable could be your choice. Many factories can provide you customized drop cables in various fiber types, fiber optic connector and lengths.

Conclusion

Customer demand for higher bandwidth will continue to drive the development of FTTH as well as its key component like drop cable. Choosing the right drop cable and drop cable termination method is as important as choosing the right network architecture in FTTH.

Source: http://www.fs.com/blog/drop-cable-and-its-termination-in-ftth.html