BOON OF USING FIBER OPTIC CABLES OVER COPPER CABLES

by www.fiber-mart.com

Everyone knows that approx.. an year ago we use copper cables while using the internet connection of any brand. The service providers come up with copper cable to install the internet connection and provide the required service to them. But at present time, fiber optic cable is in demand. The users are quite happy with its performance as it rarely gets out of connection. On the other hand, it also gives a good speed to the user in comparison to the copper cables. Let’s discuss some other best advantages of fiber optic cable over the copper cables.

 

Greater BandwidthThe 

 

copper cable has the capacity to handle greater bandwidth as originally it was designed for voice transmission and have a limited bandwidth. So, now it is used as a greater bandwidth device. It carries more data than copper cables at the same diameter. Within the fiber cable group, only single mode fiber can delivers up to twice the multimode fiber. So, users are fine with what they are availing.

 

Faster SpeedsThe 

 

fiber cables carry light to transmit data. This enables the cable to carry diverse signals at speeds that are slower than the speed of light which is faster than cat5 and cat6 copper cables. Therefore the speed this cable is higher than the copper cable.

 

Longer Distances

 

When it comes to long distance, this cable never disappoints as cables generally works on the basis of wavelength, network, distance and it performs well in each of these areas. It carries signals much faster than the traditional foot limitations upto 328ft. It carries data upto 25 miles.

 

Better ReliabilityBe 

 

it any weather, fiber cable is immune to temperature changes. Weather doesn’t hamper the connectivity of this cable as like other traditional cables. And it does not even carry electric current so user must be stressed free with electromagnetic interference (EMI) that can interrupt data transmission.

 

Thinner and Sturdier

 

In comparison to any other cable, this cable is thinner, sturdier and light in weight. It is less prone to damage and breakage.

 

More Flexibility for the Future

 

According to the demand and usage, the media converters enable the user to incorporate fiber into existing networks. The converters enhance the Ethernet connection over fiber optic by extending the UTP. Modern panels are designed to meet the current needs and provide the flexibility for future needs. The panels are comprises of variety of cassettes for different types of fiber patch cables.

 

Low Cost

 

If the user gets its ownership, then he or she will realize that in initial days the rate of fiber optic cable is a bit expensive, but its reliability, durability and speed makes it worth it. And after some days of use, it automatically becomes affordable as there are a number of packages are given to the user to choose the most affordable one.

 

Each of these advantages of fiber optic cable makes it best among all other traditional internet connections. 

Cabling Guide for Cisco Nexus 9508 Switch

Due to the the ever-expanding data center consolidation, virtualization and cloud technologies, network installers feel the urge to maintain a competitive advantage of their infrastructure. Except for the performance, bandwidth and latency in datacenter cabling, management and operational agility and simplicity have also elevated themselves to the top mind of data center architects and operator. Cisco Nexus 900 series represents a familiar starting point on the journey toward a new era in software-defined network, which is announced to be the most port dense and power efficient plus fastest packet forwarder and programmable data center modular switch in the industry. This article introduces basic information of Cisco Nexus 9000 series and the cabling solutions for Nexus 9508 switch.

 

Cisco Nexus 9000 Series Switch

 

According to Cisco’s announcement, the Nexus 9000 Series switch is the foundation of the Cisco next generation data center solution. The Cisco Nexus 9000 Series switch contains two main branches including the Nexus 9300 series fixed switches and Nexus 9500 series modular switches. Of particular interest is the Nexus 9508 of 9500 series, which is impressive in terms of performance, power efficiency, 10/40GbE and future 100GbE port density, programming environment and orchestration attributes. The following image shows the inner structure of the Cisco Nexus 9508 switch.

 

Cisco Nexus 9508 can offer up to 8 line cards slots with a comprehensive selection of modular line cards in a 13RU space. There are totally three line card options available: 48 port 1/10GbE SFP+ with four 40GbE QSFP+, 48 port 1/10GBASE-T with four 40GbE QSFP+ and 36 port 40GbE QSFP+ full line rate. The 1/10GbE line cards provide 640 Gbps of line rate capacity. And the 40GbE line card is based on QSFP+ form factor. From a network design perspective, the Cisco Nexus 9508 switch can be configurable with up to 1152 10 Gigabit Ethernet or 288 40 Gigabit Ethernet ports, which is very helpful for 10GbE & 40GbE migration.

 

Main Features of Cisco Nexus 9508 Switch

 

The Cisco Nexus 9508 is a versatile data center switching platform that can host 10, 40, and future 100 Gigabit Ethernet interfaces. Other than this, the switch also has other unique features:

 

Predictable high performance—The switch delivers 30 Tbps of non-blocking performance with latency of less than 5 microseconds, enabling data center customers to build a robust network fabric that can scale from as few as 200 10 Gigabit Ethernet server ports to more than 200,000 10 Gigabit Ethernet server ports.

 

Nonblocking, high-density 1 to 10 & 10 to 40 Gigabit Ethernet transition—The Cisco Nexus 9500 platform helps organizations transition from existing 1 Gigabit Ethernet Cisco Catalyst®6500 series switches server access designs to 10 Gigabit Ethernet server access designs with the same port density. And it can also helps organizations transition from 1 and 10 Gigabit Ethernet infrastructure to 10 and 40 Gigabit Ethernet infrastructure to support the increased bandwidth demands.

 

Advanced optics—This switch can directly use the pluggable 40 Gigabit Ethernet QSFP+ bidirectional transceiver that enables customers to use existing 10 Gigabit Ethernet data center cabling to support 40 Gigabit Ethernet connectivity.

 

Highly available, scalable, and robust solution—All major components are redundant, including supervisors, system controllers, power supplies, and fan trays. The switch line cards use a mix of merchant and Cisco application-specific integrated circuits (ASICs) to produce a low-complexity, low-cost design. All buffer memory is integrated into the forwarding ASICs, avoiding the need for a large number of external memory modules.

 

All transceivers are pluggable to support the highest possible mean time between failure (MTBF) for the switch. What’s more, the flexible and efficient chassis design has 100% headroom for future expansion with the capability to support more bandwidth and cooling and twice the number of power supplies needed to support today’s maximum configuration.

 

Power efficiency—The Cisco Nexus 9500 platform is the first switch chassis designed without a midplane. Line cards and fabric modules connect directly. This design approach provides optimal front-to-back airflow and helps the switch operate using less power. In addition, all Cisco Nexus 9000 series power supplies are 80 Plus Platinum rated. The typical power consumption per 10 Gigabit Ethernet port is less than 3.5 watts (W). The typical power consumption of each 40 Gigabit Ethernet port is less than 14W.

 

QSFP+ Direct Attach Copper Cabling

 

As we all know, direct attach cables (DACs) are often used to connect two or more switches which are in the same rack or in the adjacent rack. This is done to reduce the cabling cost for which DACs are much cheaper than transceivers and fiber patch cords. The following figure shows a wiring option for a Cisco Nexus 9396 to Cisco Nexus 93128 using 40G QSFP+ to 40G QSFP+ DAC cabling assemblies.

 

40G QSFP+ to 4 x 10 SFP+ Interconnection

 

The Cisco Nexus 9508 switch can also be operated in 4×10 Gigabit Ethernet mode. If the interface is logically configured as a 4×10 Gigabit Ethernet port, then each port becomes four 10Gbqs port. This will be accomplished by using copper twinax, hydras or breakout cables. This scenario can be achieved by connecting a Cisco Nexus 9000 Series Switch to a Cisco Nexus 2232 using a QSFP+ to four SFP+ copper hydra cable assembly.

 

40GE QSFP SR4/CSR4 Optics Cabling Options

 

Multimode fiber cabling is generally preferred when the distance between Cisco Nexus 9508 switch and other switches is less than 400 meters. In this circumstance, 40G QSFP+ SR4/CSR4 transceivers and MPO interconnect cable assemblies are often used. The following scenario shows how the Cisco Nexus 9508 switch is connected to Cisco Nexus 93128 switches with 40G QSFP+ SR4/CSR4 optics and MPO cable assemblies.

 

40GbE Connectivity With 40G BiDi Optics

 

As noted before, Cisco 40G SR-BiDi QSFP can be used in Cisco Nexus 9508 switch for 40G connectivity. The 40G BiDi QSFP multiplexes two 10GbE signals into one 20GbE stream and runs two 20GbE wavelengths on the optics side, and delivers a QSFP pluggable MSA compliant electric signal to the switch module, thereby only requiring the termination of a dual LC connector as used in 10GbE optical infrastructure. The SR-BiDi QSFP enables the re-use of existing 10GbE multimode fiber cable infrastructure plus patch cables as it supports the same LC connector. The SR-BiDi QSFP eliminates the cable infrastructure upgrade requirement of today’s 40GbE, which can lower capex of cabling and switch hardware. The following image shows the Cisco Nexus 9508 switch using 40G BiDi transceiver providing a zero-cost fiber cabling upgrade path for 10GbE to 40GbE.

 

Cisco is offering a practical way to transition to higher speed data center networking through favorable economics. With the use of Cisco Nexus 9508 switch, designers will embrace a new programmable network platform ready for the age of software-defined networking. fiber-mart.COM provides various 40G QSFP+ transceivers and fiber optic cable for the 40G connection of Cisco Nexus 9508 switch. 10G SFP+ transceivers and MPO/MTP-LC harness fiber patch cables for the 10G SFP+ to 40G QSFP+ direct connection are also provided. 

What Will Affect the Longevity of Your Fiber Network?

When deploying a fiber network, people nowadays not only appreciate the high-speed broadband services, but the maintenance of how long it will last. After all, optical fiber is a particular type of hair-thin glass with a typical tensile strength that is less than half that of copper. Even though the fiber looks fragile and brittle, but if correctly processed, tested and used, it has proven to be immensely durable. With this in mind, there are essentially factors that will affect the longevity of your fiber network.

 

Installation Strains

 

Stress, on the other hand, is a major enemy of fiber longevity, so the protection task is passed to the cable installer, who will ensure that the use of suitable strength elements limits the stress applied to the cable to much less than the 1 per cent proof test level. The installer then needs to ensure that the deployment process does not overstrain the cable. Figure 2 below illustrates a typical crew deployment for a trunk installation. The whole process should be paid more attention to the stress.

 

Of the three techniques commonly used—pulling, pushing and blowing, only pulling creates undesirable stretching (tensile stress). Unlike metal, glass does not suffer fatigue by being compressed, and so the mild compression caused during pushing causes no harm to the fiber.

 

Surface Flaws

 

Optical fiber typically consists of a silica-based core and cladding surrounded by one or two layers of polymeric material (see in Figure 3). Pristine silica glass that is free of defects is immensely resistant to degradation. However, all commercially produced optical fibers have surface flaws (small micro-cracks) that reduce the material’s longevity under certain conditions. The distribution of flaws on the surface of the silica-based portion of the fiber largely controls the mechanical strength of the fiber. fiber-mart.COM fiber optic cables are well tested to ensure less surface flaws, like LC to ST fiber cable.

 

To conquer this, reputable fiber suppliers carry out proof testing, which stretches the fiber to a pre-set level (normally 1 per cent) for a specified duration to deliberately break the larger flaws. And the user is then left with a fiber containing fewer, smaller flaws that need to be protected from unnecessary degradation. This means primarily stopping the creation of new flaws by coating the fiber with a protective and durable material for its primary coating.

 

Environmental Factors

 

Once deployed, the local environment has a big impact on fiber life. Elevated temperatures can accelerate crack growth, but it is the presence of water that has been historically of most concern. The growth of cracks under stress is facilitated by water leading to “stress corrosion”. You can check what the tendency of a fiber to suffer stress corrosion is by reviewing its “stress corrosion susceptibility parameter”, much more conveniently referred to as “n”. A high n value (around 20) suggests a durable fiber and coating.

 

Calculating How Long Your Network Will Last

 

Bearing in mind the three factors above, how can you calculate the lifetime of your fiber network? In general, the chances of a fiber being damaged by manual intervention, such as digging, over the same time frame is about 1 in 1,000. Quality fiber, installed by benign techniques and by careful installers in acceptable conditions should, therefore, be extremely reliable – provided it is not disturbed.

 

It is also worth pointing out that cable lengths themselves have rarely failed intrinsically, but there have been failures at joints where the cable and joint type are not well matched, allowing the fibers to move – for example, due to temperature changes. This leads to over stress of the fiber and eventual fracture.

 

Conclusion

 

To tell the truth, the biggest enemies to the carefully engineered reliability of fiber jumper can be either humans or animals, rather than the fused silica itself. The provided fibers are stored and coiled correctly, it is quite possible that they turn out to be stronger than we at first thought and perhaps the original flaws begin to heal with time and exposure to water under low stress levels. fiber-mart.COM offers high quality fiber cable assemblies such as Patch Cords, Pigtails, MCPs, Breakout Cables etc. All of our products are well tested before shipment. If you are interested, you can have a look at it.

Fiber Optic Fusion Splicing – Arc Checking and Maintenance

Working with fiber optics takes a delicate hand and some patience. One of the most used pieces of equipment is a fusion splicer. A fusion splicer uses an electric arc to fuse two pieces of optical fiber (glass) together so that light can pass through with no scatter of light or light reflected back (backscatter) by the splice. Fusion splicing helps to reduce loss in your network. Typical loss through a fusion splice is .01dB to .05dB. When using these machines there are some important things that you need to do, as well as steps to maintain them. There are a few different types of splicers, as well as a couple of different concepts of splicing. We will discuss these and some other key points about splicing.

 

Different Types of Fusion Splicers

 

There are several different types of splicers. We have V-Groove splicers. These splicers typically only have one camera and align the fiber using the grooves that help to make sure that the cladding of both sides is matched up. These tend to be the low cost splicers which do not have sophisticated motors in them.

 

Then there is the active cladding alignment splicer. This type does have motors that move on the X and Y axis but it is still aligning the fibers by the cladding and not the core. These tend to be priced about a couple thousand higher than the V-Groove splicers.

 

Finally, you have a core alignment splicer that uses more than one camera to align your glass fibers by the core or center of your fiber. These were the first splicers that were on the market. This was due to early fiber having very poor concentricity of the core of fiber. These machines are also the most expensive of the splicers because of the advanced technology that is needed to align the fibers up by the cores.

 

Arc Checks

 

When you are splicing, there are certain things that need to be done every time before you start splicing your fibers together. The main thing is known as an arc check. This process is to make sure that your splicer is ready and able to help you complete your job without any hiccups. Arc checking will help to make sure a fusion splicer is tuned up for environmental conditions as well as that your machine settings are ideal for you to splice. One thing that is always brought up when performing this operation, is that when doing an arc check, single mode fiber should always be used whether you are splicing multimode or single mode that splicing session. Go to your splicer’s menu and click on the “Arc Check” setting. While doing this the splicer is looking at several different factors that can play a role that affects the splicer’s performance. Weather is a big part of this. It looks at the humidity, temperature and overall performance of the machine to have the perfect formula for the conditions at your job site. This process may need to be repeated several times before your machine is ready to splice. I have heard as many as fifteen times before it was ready, but usually one or two works. So - one thing most people don’t realize is, when splicing throughout the day - as the temperature changes another arc check may need to be performed later in the day. So you start splicing at ten in the morning and it is 65 degrees. You take a break for lunch around noon. When you get back the temperature is now 75 degrees and it has become more humid. Before you start splicing, an arc check should be performed as the temperature and humidity difference will cause your splicer to not be properly ready to splice in the different conditions.

 

Maintenance of the Splicer

 

There are a couple of things that can be done with your splicer to make sure it is well maintained and running to help complete important jobs. One of the most important pieces of your splicer is the heart of your fusion splicer. That piece being the electrodes. The electrodes are a pair of conductors that electricity flows through and this is what fuses your two pieces of fiber together. The electrical arc does wear them down over a period of arcs. The recommended number of arcs before these should be changed is typically a thousand. Now, there are some others out there that are trying to extend this amount by three times this. In this case, just keep an eye on your splice losses to determine when to change the electrodes. As the splice loss estimates get higher, your machine is closer to needing the electrodes to be changed. Another key part of splicing that needs to be maintained is your precision cleaver. A cleaver is the tool that you will use to score and cut the fiber so it can make a good splice. A cleaver has a wheel that rotates - this is known as the blade. This blade wears down and also needs to be managed with a certain number of good cleaves per position on the blade. Without good maintenance of your electrodes and cleaver your equipment can shut down a job or cause problems with your splicer.

 

Different Methods of Splicing

 

When splicing, there are a couple of different reasons why you do optical fiber splicing. In the end, it is all the same concept but there are different reasons to splice. The first one is to extend a fiber cable. This is where you will splice two different lengths together. This happens when a break occurs and you will use some of the excess fiber cable originally pulled to put your link back together. This can also be in a new deployment when you need to go a greater distance over what is the max length of fiber optic cabling that can be placed on a spool. When doing the long haul applications the core alignment splicer is the recommended machine.

 

The next two are the same concept just a different approach. This concept is to terminate the ends of your fiber. The first one is splicing on pigtails. Pigtails are a piece of fiber that is blunt on one side and has a factory polished connector on the other end. So you are splicing fiber to fiber and putting a splice protection sleeve (a heat shrinkable tube that contains a ceramic or stainless steel strength member) on to protect the splice. These will typically require a splice tray to put your splices in to protect them. The other concept is a splice on connector. This is also a pigtail but it is a lot shorter and uses a holder that is placed in the splicer. This allows your splice protection sleeve to be covered by the connector boot and does not require any splice trays.

 

So remember, always arc check using single mode fiber before beginning any splicing session, whether you are splicing single mode fiber or multimode fiber that day. Maintain your fusion splicer and your precision cleaver on a regular basis and your jobs will go much smoother. A fusion splicing machine can be a tech's best friend, or his worst nightmare!

100G QSFP28 Fiber Optic Modules and Standards

The developing of 100G fiber optic transceiver has experienced a lot of challenges, thus various types of 100G fiber optic transceivers are being invented. Many 100G modules appeared on the market for a while and disappeared soon. Now it seems that 100G QSFP28 module will win the competition. It has the same cabling structure as 40G QSFP+ module and high density feature, which allows network upgrade to 100G with lower cost and less time. This post will introduce several commonly used 100G QSFP28 modules and standards.

 

QSFP28 module uses four lanes for 100G optical signal transmitting like 40G QSFP+. However, each lane of QSFP28 can transmit 25G optical signal. To fit the various requirements in practical applications, IEEE and MSA standards that support different transmission distances and fiber types are being published.

 

100G QSFP28 SR4 

100G QSFP28 SR4 is a standard published by IEEE. 100G QSFP28 SR4 module uses eight multimode fibers for 100G dual-way transmission over 850nm. It can support a transmission distance up to 70m over OM3 and 100m OM4 with a MTP interface. 12-fiber MTP OM3/OM4 trunk cables are suggested to be used with QSFP-100G-SR4 modules. 100Gbase-SR4 QSFP28 is the most popular QSFP28 module according to research.

 

100G QSFP28 LR4

100G QSFp28 LR4 is another 100G standards published by IEEE. It focuses on longer transmission distance over single-mode fiber. 100G QSFP28 LR4 has a duplex LC interface and uses WDM technologies to achieve 100G dual-way transmission over four different wavelengths around 1310nm. It can support distances up to 10km.

 

Although IEEE has defined two 100G standards separately for short and long distances, the requirements of various applications cannot be fully satisfied. For instances, the 100G-QSFP-LR4 module can support 10km, which is too much for a lot of single-mode applications. It would be uneconomical to buy a 10km module for just 1km or 2km application. MSA has published two 100G standards — 100Gbase-PSM4 and 100Gbase-CWDM4, which can help to decrease the cost of 100G deployment.

 

100G QSFP28 PSM4

100G QSFP28 PSM4  module has a MTP interface working on wavelength of 1310nm for 100G transmission over single-mode fibers. It can support transmission distance up to 500 meters. 100G QSFP28 PSM4 module is much cheaper than 100Gbase-LR4 QSFP28 module. And 500 meter’s transmission distance can cover a wide range of applications.

 

100G QSFP28 CWDM4

For longer transmission distance, 100G QSFP28 CWDM4 is suggested, which supports a distance up to 2km over single-mode fiber optic cable. 100Gbase-CWDM4 standard is published by MSA, which is a more cost-effective solution for a wide range of applications compared with 100Gbase-LR4. This module uses CWDM technologies to transmit the 100G optical signal via a duplex LC interface over wavelengths near 1310nm.

 

100G QSFP28 DAC

100G QSFP28 family also includes a series of direct attach cables. There are mainly two types of QSFP28 DAC, which are QSFP28 to QSFP28 DAC and QSFP28 to SFP28 DAC. These QSFP28 DACs are cost-effective solution for 100G transmission less than 5 meters.

 

Conclusion

There are many ways to transmit to 100G network. 100G QSFP28 modules are the suggested methods. Both IEEE and MSA published standards for 100G QSFP28. For short distance transmission over multimode, 100Gbase-SR4 QSFP28 module is suggested. For single-mode applications, 100Gbase-PSM4 supporting 500m, 100Gbase-CWDM4 supporting 2km and 100Gbase-LR4 supporting 10km are available. The above table shows the basic information of these modules for your reference.