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Can I Use the QSFP+ Optics on QSFP28 Port?

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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 transceiver. 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.

QSFP can work on the QSFP28 ports

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.

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

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

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

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

1000Base-SX standard

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

1000BASE-LX SFP

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

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

Related Article: Compatible SFP for Cisco 2960 Series Switches

How to Handle Challenges of CWDM Testing?

CWDM technology has proven itself to be a cost-effective and simplified method for network managers to optimize the existing infrastructure. The adoption of CWDM system into metro and regional network is constantly on the rise and it also extends the reach to the access networks. CWDM is becoming more widely accepted as an important transport architecture owing to its lower power dissipation, smaller size, and less cost. This article will focus on the challenges concerning CWDM testing, and provide several methods to help overcome them.

Basic Configurations of CWDM Network

CWDM configuration is usually based on a single-fiber pair: one fiber is for transmitting and the other for receiving. The following figure shows the most basic configuration of optical network with 4 channel CWDM MUX/DEMUX: it often delivers eight wavelengths, from 1471 nm to 1611 nm, with 20 nm apart. A CWDM architecture is quite simple. It only has passive components like multiplexers and demultiplexers, without any active elements such as amplifiers. However, using CWDM as a means of increasing bandwidth also brings network characterization and deployment challenges, which will be discussed in the following section.

cwdm basic configuration

Challenges and Solutions for CWDM Testing

The challenges of CWDM testing mainly lie in three phases: construction and installation, system activation and upgrade or troubleshoot. Here we provide solutions for each.

Challenge One: Construction and Installation

During construction and installation process, it is essential to conduct physical-layer tests on the fiber from the head-end to the destination. Single-ended testing with an OTDR is definitively an advantage as it optimizes labor resources. In this case, the objectives are to characterize the entire link (not only the fiber) to include the add-drop multiplexers (OADM) and to guarantee continuity up to the final destination. However, testing at standard OTDR wavelengths, such as 1310 nm and 1550 nm, cannot be done in such conditions as these wavelengths are filtered out at either OADM, never reaching the end destination. Then how to test such a link?

cwdm otdr testing

Solution: Adopting a specialized CWDM OTDR. With CWDM-tuned wavelength, the CWDM OTDR is capable of performing an end-to-end test by dropping each test wavelength at the correspondent point on the network, allowing the characterization of each part of the network directly from the head-end. Which is considered time and labor saving since one don’t have to access. It also helps to speed up the deployment process as the technician will test all drop fibers from a single location.

Challenge Two: System Activation

Since CWDM architecture is rather basic which contains no active components like amplifiers, the only things that can prevent proper transmission in a CWDM system are transmitter failure, sudden change in the loss created in an OADM or manual errors, bad connections for example. To deal with these problems, one has to look at the signal being transmitted.

Solution: A CWDM channel analyzer is ideal to handle this challenge. It works to quickly determine the presence or absence of each of the 16 wavelengths and their power levels. Many CWDM OADM have tap ports, which means that there is a port where a small portion of the signal is dropped. Taps are typically 20 dB weaker than the main signal. If these taps are not present, a CWDM analysis should be performed. It consists of unplugging the end user to use the main feed for the analysis. To be ready for all possibilities, a CWDM channel analyzer should cover a power range going as low as –40 dBm, while being able to test the entire wavelength range in the shortest time as possible.

Challenge Three: Upgrade or Troubleshoot

In the maintenance and troubleshoot phrase, when the network is live and a new wavelength is added, one should figure out two questions: is the link properly set up? And is my wavelength presents and well?

out-of-band testing of cwdm

Solution: Two approaches are available to check if a link is set up properly: a CWDM OTDR approach or an out-of-band approach. The CWDM OTDR approach is relatively simple when a new customer is added. With CWDM OTDR, one can perform CWDM testing without having to wait for the customer or to go to the cell tower sites. The wavelength can be turned on at the head-end. Which speed testing process greatly.

The OTDR and channel analyzer combo are also useful when a single customer has issues. The channel analyzer will reveal if the channel is indeed present and within power budget. If not, the CWDM OTDR can be used to test at that specific wavelength or an out-of-band 1650 nm OTDR test can be performed from the customer’s site to detect any anomalies on the link, all without disconnecting the head-end since the OADM will filter out the 1650 nm, therefore not affecting the remainder of the network.

Conclusion

CWDM testing challenges may be inevitable during each phase of the deployment, but with specialized equipment, these challenges can be overcomed completely. Tools including a CWDM OTDR, a CWDM channel analyzer and an out-of band OTDR are proved effective and valuable to reduce downtime and increase bandwidth at a minimum cost.

How to Achieve 10GB in Your Home Lab Under $70?

A lot of small to medium businesses haven’t made the transition over to 10Gb speeds from the typical 1Gb (at least around where I live), let alone us homelabbers, because of it’s cost. Even with “cheaper” 10GBASE-T switches coming out, like the D-Link DXS-1210-12TC, $1,470 is still a lot more than most of us can convince our wives to let us spend on one. Also, do you have 10Gb NICs on your hosts and NAS/SANs? What about the right cables? These things aren’t cheap.

Inspired by a Reddit post I found over on the /r/homelab subreddit, I decided to try a 10Gb point-to-point connection between my ESXi host (a Dell PowerEdge R520) and my HP ProLiant DL320e that I’m using as my mini-SAN (running Windows Server 2016 TP4). For those that don’t know, a point-to-point connection is a small network between two endpoints or clients, so no switch is needed. My switch (an HP ProCurve 2920) doesn’t have the 10Gb modules needed but I wanted the 10Gb connection between my ESXi host and SAN anyway, so a P2P connection between those two would be perfect.

The NICs talked about in the /r/homelab thread were used HP Mellanox ConnectX-2 10GbE NICs you can find on eBay for SUPER cheap (currently $18.78 each on eBay) connected via this 10GBASE SFP+ cable for $22.94 shipped. I found the NICs to be widely supported but I couldn’t find a lot of information on just how supported they are on the newest operating systems. My host is running ESXi 6 while my ProLiant is running Windows Server 2016 TP4, but for a total of about $65, it was worth the risk of not being supported.

10GBASE SFP+ cable

UPDATE: Thanks to Reddit user /u/negabiggz for mentioning that these Mellanox ConnectX-2 NICs do not work under FreeNAS. If you’d still like to create a cheap 10Gb P2P connection in FreeNAS, you can pick up these Chelsio S310E-CR 10Gb NICs on eBayor (shown in figure below) wait till the drivers are natively supported in version 10.1.

Chelsio S310E-CR 10Gb NICs

About a week after placing the orders for the NICs and cable, these two beautiful pieces of used hardware came in along with the SFP+ cable. I immediately took the R520 and ProLiant DL320e out of my rack and got them both easily installed. I fired both machines up and got what every sysadmin and/or homelabber loves to see: both NICs working properly out of the box. Turns out ESXi 6 AND Server 2016 TP4 really do support these cheap, beautiful NICs without the need to install/uninstall/reinstall a ton of different drivers.

maul

This is a screenshot of the 10Gb NIC on my ProLiant right after booting it up and configuring the static IP.

esxi
This is a screenshot of the NIC on my ESXi host after booting it up and getting the other NIC configured on my 2016 TP4 box.

I haven’t done a lot of speed tests to get the official read/write speeds, but I have added the 10Gb NIC to my media downloading VM and transferred a few 720p TV episode files between them and my ProLiant. I tried to take a screenshot of the transfer rate when I copied over a 1GB 720p episode of a TV show I downloaded (legitimately, I swear!), but the screen never came up. I didn’t even get a chance to screenshot it. It was like I just moved the video between folders on the same drive. I also configured an iSCSI connection using the 10Gb link and performance so far has been great.

So there you have it. An awesome 10Gb speed on your homelab all for under $70. Thanks to the /r/homelab community for the idea and for suggesting the hardware, especially for those of us that didn’t want to convince our wives why we need to spend hundreds of dollars so we can transfer files using a puny 1Gb connection.

Source: https://thatservernerd.com/2016/02/23/10gb-in-your-homelab-for-under-70

Armored Fiber Optic Cable

Definition of armored fiber optic cable
Armored Fiber Optic Cable, just as the name implies, is that there is a layer of additional protective metal armoring of the fiber optic cable.
Armored Fiber CableFunction
Armored fiber cable plays a very important role in long-distance line of fiber optic cable. A layer of metal armoring in the scarf-skin of fiber optic cable protects the fiber core from rodent, moist and erosion.

Classification
According to the place of use, there are indoor armored fiber optic cables and outdoor armored fiber optic cables.

Indoor armored fiber optic cable
Indoor armored fiber optic cable is mainly used in interior, so it must be flexible and can be installed in the corner and some narrow places. Besides, indoor armored fiber optic cable experiences less temperature and mechanical stress, but they have to be fire retardant, emit a low level of smoke in case of burning. And indoor armored fiber cables must allow a small bend radius to make them be amendable to vertical installation and handle easily.

Indoor armored fiber optic cable can be divided into simplex armored fiber optic cable and duplex armored fiber optic cable. The main difference is that simplex armored fiber optic cable is the cable that not contains stainless steel wire woven layer, and duplex armored fiber optic cable is the cable that contains stainless steel hose and stainless steel wire woven which are of compressive property, resistance to deflection, rodent resistance, anti-torque and so on.

Outdoor armored fiber optic cable
Outdoor armored fiber optic cables are made to protect the optical fiber to operate safely in complicated outdoor environment. Most armored outdoor fiber cables are loose buffer design, with the strengthen member in the middle of the whole cable, the loose tubes surround the central strength member.

Outdoor armored fiber optic cable can be divided into light armored fiber optic cable and heavy armored fiber optic cable. Light armored fiber optic cable is with steel tape and aluminium tape which can strengthen rodent protection. Heavy armored fiber optic cable is equipped with a circle of steel wire, and usually used in riverbed and seabed.

Installation
There are two installation methods of armored fiber optic cable. One is buried directly in the ground, and the other is aerial optical cable.

For direct burial fiber cable, armored fiber optic cable is in the position to resist external mechanical damage, prevent erosion and resist rodent. In addition, because of different soil and environment, the depth of burying under the ground is about between 0.8m-1.2m.

On the other hand, aerial optical cable is the optical cable that hanging on the pole. This kind of installation way of armored fiber optic cable can prevent fiber core from any kind of severe environment, such as typhoon, ice, and people or animals. Aerial armored optical cable mostly uses central loose tube armored fiber optic cable (GYXTW) and stranded loose tube armored fiber optic cable (GYTA). The features of GYXTW are that can contain up to 12 fiber cores, the loose tube is centrally situated with good excess length and minimizes the influence of lateral crush, and double wire as strength member provides excellent strain performance. GYTA is suitable for installation for long haul communication and LANs, especially suitable for the situation of high requirements of moisture resistance. GYTA is with compact structure; the cable jacket is made of strong Polyethylene. This armored fiber optic cable features the good mechanical and temperature performance. GYTA is also with high strength loose tube that is hydrolysis resistant and the optical cable filling materials ensure high reliability, its APL makes the cable crush resistant and moisture proof. The GYTA fiber optic cable is available from 2 cores to 144 cores.

The Introduction of Optical Power Meter

What Is an Optical Power Meter?
optical power meterAn Optical Power Meter usually knows as Fiber optical power meter is a device that used to measure the absolute optical signal and relate fiber optic loss. The term usually refers to a device for testing average power in fiber optic systems. Fiber optical power meter is a tool for telecommunication and CATV network. Optical power meter consists of a calibrated sensor, measuring amplifier and display. The sensor primarily consists of a photodiode selected for the appropriate range of wavelengths and power levels. On the display unit, the measured optical power and set the wavelength are displayed. Power meters are calibrated using a traceable calibration standard such as a NIST standard.

When to Use Optical Power Meter?
When you install and terminate fiber optic cables, you need to test them. A test should be conducted for each fiber optic cable plant for three main areas: continuity, loss, and power. In order to do this, you’ll need a fiber optic power meter.

How to Use Optical Power Meter?
When you measure fiber optic power with a power meter, you should attach the meter to the cable. Turn on the source of power, and view the meter’s measurement. Compare the meter measurement with the specified correct power for that particular system to make sure it have proper power not too much or too little . Correct power measurement is so important to fiber optic cables because the system works similar to electric circuit voltage, and the power must be just the right amount to work properly.

Classification of Optical Power Meter
There are two types of Optical Power Meter: Ordinary Optical Power Meter and PON Optical Power Meter. Ordinary optical power meter measures the optical power in the fiber link, typically an absolute power value 850/1300/1310/1490/1550/1625nm optical wavelength. While PON Optical Power Meter is more suitable for measuring the fiber to the home (FTTH) networks. Specific measurement: PON Optical Power Meter can send three wavelengths from a single laser output port (1310 nm, 1490 nm, 1550 nm), of which 1310nm can measure upstream transmission direction, 1490 nm and 1550 nm measure downstream direction. Upstream associated with your upload data, downward is download data.

Tips for Selection and Operation

  • Choose the best probe type and interface type.
  • Evaluation of calibration accuracy and manufacturing calibration procedures, and your fiber and connectors to match the required range.
  • Make sure the type and the range of your measurement and display resolution is consistent.
  • With immediate effect db insertion loss measurements.
  • Wear eye protection when working with high-power cables. Even with low-power layouts, it’s wise to check the connectors with your power meter before looking.

Some Common Types of Indoor Cables

Optical fiber cables for indoor cabling are used for the construction of horizontal subsystem and SCS building backbone cabling subsytems. They differ form cables used for outdoor cabling by two key parameters.

Indoor fiber optic cable is tight buffer design, usually they consist of the following components inside the cable, the FRP which is non-metallic strengthen member, the tight buffer optical fiber, the Kevlar which is used to further strength the cable structure, making it resist high tension, and the cable outer jacket. The trend is to use LSZH or other RoHS compliant PVC materials to make the cable jacket; this will help protect the environment and the health of the end users.

Indoor Cables

Cables for indoor applications include the following:

* Simplex cables
* Duplex cables
* Multifiber cables
* Heavy-, light-, and plenum-duty cables
* Breakout cables
* Ribbon cables

Although thes categories overlap, they represent the common ways of referring to fibers. Figure 7-5 shows cross sections of several typcial cables types.

Simplex Cables

A simplex fiber cable consists of a single strand of glass of plastic fiber. Simplex fiber is most often used where only a single transmit and/or receive line is required between devices or when a multiplex data signal is used (bi-directional communication over a single fiber).

Duplex Cables

A duplex fiber cable consists of two strands of glass or plastic fiber. Typically found in a “zipcord” construction format, this cable is most often used for duplex communication between devices where a separate transmit and receive are required.

Duplex cable is used instead of two simplex cables for aesthetics and convenience. It is easier to handle a single duplex cable, there is less chance of the two channels becoming confused, and the appearance is more pleasing. Remember, the power cord for your lamp is a duplex cable that could eaily be two separate wires. Does a single duplex cord in the lamp not make better sense? The same reasoning prevails with fiber optic cables.

Loose Tube Cables

loose tube cable

The loose tube variety contains one or more hard buffer tubes, which house between 1 and 12 coated fibers. The hard buffer tubes are also filled with a gel to provide vibration and moisture protection for the fibers. The fibers lie loosely in the tubes, which are wound into the cable in a reversing helical fashion and are actually longer than the outer sheath of the cable. This arrangement allows for a small amount of stretch in the outer sheath when installing the cable. Loose tube cable is used most often in OSP construction because it is designed for a tough outdorr environment use. See Figure-1 for the physical make-up of a typical loose tube cable.

Breakout Cables

Breakout cabke

Breakout cables have several individual simplex cables inside an outer jacket. The breakout cables shown in Figure 2 use two dielectric fillers to keep the cables positioned, while a Mylar wrap surrounds the cables/fillers. The outer jacket includes a ripcord to make its removal fast and easy. The point of the breakout cable is to allow the cable subunits inside to be exposed easily to whatever length is needed. Breakout cables are typically available with two or four fibers, although larger cables also find use.

Ribbon Cables

ribbon cable

Ribbon cable uses a number of fibers side by side in a single jacket. Originally, Ribbon fiber cable was used for outdoor cables (see Figure 3). Today they also find use in premises cabling and computer applications. The cables, typically with up to 12 fibers, offer a very small cross section. They are used to connect equipment within cabinets, in network applications, and for computer data centers. In addtion, they are comatible with multifiber array connectors. Ribbon cables are available in both multimode and single-mode versions.

Related Article:  Which Patch Cable Should I Choose for My Optical Transceiver?

The Application and Types of Armored Fiber Optic Cable

What Is Armored Fiber Optic Cable?
Armored fiber optic cable consists of a cable surrounded by a steel or aluminum jacket which is then covered with a polyethylence jacket to protect it from moisture and abrasion. It may be run aerially, installed in ducts, or placed in underground enclosures with special protection from dirt and clay intrusion.

armored fiber optic cable

Armored fiber optic cable is often installed in a network for added mechanical protection. Two types of armoring exist: interlocking and corrugated. Interlocking armor is an aluminum armor that is helically wrapped around the cable and found in indoor and indoor/outdoor cables. It offers ruggedness and superior crush resistance. Corrugated armor is a coated steel tape folded around the cable longitudinally. It is found in outdoor cables and offers extra mechanical and rodent protection.

Types Of Armored Cable

indoor armored cable

Armored cable can be divided into indoor armored cable and outdoor armored cable. With the fast development of fiber optic communication technology and the trend of FTTX, indoor fiber optic cables are more and more required to be installed between and inside buildings. Typical indoor armored cable types include GJFJV, GJFJZY, GJFJBV, GJFJBZY, GJFDBV and GJFDBZY. Compared with outdoor use fiber cable, indoor fiber cable experience less temperature and mechanical stress, but they have to be fire retardant, emit a low level of smoke in case of burning. And indoor armored cables allow a small bend radius to make them be amendable to vertical installation and handle easily.

Features of Indoor Armored Fiber Cable

* Good mechanical property and environment property.
* Soft, agility, convenience for connect.
* Flexible and Easy to Handle
* Cables with Improved Attenuation Available
* Adapt to harsh environments and man-made damage.

outdoor armored fiber cable

Outdoor Armored Fiber Cable are made to protect the optical fiber to operate safely in complicated outdoor environment. Most Outdoor Armored fiber cables are loose buffer design, with the strengthen member in the middle of the whole cable, the loose tubes surround the central strength member. Inside the loose tube there is waterproof gel filled, whole cable materials used and gels inside cable between the different components (not only inside loose tube) will help make the whole cable resist of water.

Features

* Excellent attenuation performance
* Dry water blocking for moisture protection
* Polyethylene jacket for weather and UV protection
* Breakout kits available
* Corrugated Steel Tape
* Rodent Resistant
* Waterblock gel available

Application of Armored Cable

Armored fiber optic cable is used in direct buried outside plant applications where a rugged cable is needed and/or for rodent resistance. Armored cable withstands crush loads well, for example in rocky soil, often necessary for direct burial applications. Cable installed by direct burial in areas where rodents are a problem usually have metal armoring between two jackets to prevent rodent penetration. Another application for armored cable is in data centers, where cables are installed under the floor and one worries about the fiber cable being crushed. Indoor armored cables may have nonmetallic armor. Metallic armored cable is conductive, so it must be grounded properly.As with other fiber optic components, there are different names or meanings used. “Armor” in some companies’ jargon denotes a twisted heavy wire rope type cable surrounding the entire poly cable sheath/jacket. Single or double armor (two opposite ply layers of the steel wire) is typically used underwater near shore and shoals. Inner metallic sheath members of aluminum and/or copper are used for strength and for buried cable locating with a tone set.

Related Article:  Which Patch Cable Should I Choose for My Optical Transceiver?

What’s Difference Between CFP and CXP Transceivers?

Two years ago, though everyone is talking about the 100G Ethernet as the next generation, it had still faced a lot of problems to be solved, seeming to be a long way off. But, technologies are developed very rapidly, and now 100G Ethernet is becoming more and more closer to us. Fiber connectivity in higher-speed active equipment is being condensed and simplified with plug-and-play, hot-swap transceiver miniaturization. Thus, optical transceiver technology is one of the basic but important technology to achieve the realiable and effective 100G Ethernet. Interfaces for 100G active equipment include CFP and CXP. So, what are CFP and CXP? And what’s the difference between CFP and CXP? Is CXP transceiver designed to replace the CFP? … You might be interested in them and have a lot of questions in your mind. Today, you will find the answer in this post.

About CFP
cfp-100g85-1m-ju-01CFP, short for C form-factor pluggable, is a multi-source agreement to produce a common form-factor for the transmission of high-speed digital signals. The c stands for the Latin letter C used to express the number 100 (centum), since the standard was primarily developed for 100 Gigabit Ethernet systems. In fact, CFP also supports the 40GbE. When talking about CFP, we always define it as multipurpose CFP, compared to the CXP which is discussed later.

The CFP MSA was formally launched at OFC/NFOEC 2009 in March by founding members Finisar, Opnext, and Sumitomo/ExceLight. The CFP form factor, as detailed in the MSA, supports both single-mode and multi-mode fiber and a variety of data rates, protocols, and link lengths, including all the physical media-dependent (PMD) interfaces encompassed in the IEEE 802.3ba standard. At 40GE, target optical interfaces include the 40GBase-SR4 for 100 meters (m) and the 40GBase-LR4 for 10 kilometers (km). There are three PMDs for 100 GE: 100GBase-SR10 for 100 m, 100GBase-LR4 for 10 km, and 100GBase-ER4 for 40 km.

CFP was designed after the Small Form-factor Pluggable transceiver (SFP) interface, but is significantly larger to support 100Gbps. The electrical connection of a CFP uses 10 x 10Gbps lanes in each direction (RX, TX). The optical connection can support both 10 x 10Gbps and 4 x 25Gbps variants. CFP transceivers can support a single 100Gbps signal like 100GE or OTU4 or one or more 40Gbps signals like 40GE, OTU3, or STM-256/OC-768.

The CFP-MSA Committee has defined three form factors:

  • CFP – Currently at standard revision 1.4 and is widely available in the market
  • CFP2 – Currently at draft revision 0.3 is half the size of the CFP transceiver; these are recently available in the market
  • CFP4 – Standard is not yet available, is half the size of a CFP2 transceiver, not yet available

CFP transceiver today to future

The original CFP specification was proposed at a time when 10Gbps signals were far more achievable than 25Gbps signals. As such to achieve 100Gbps line rate, the most affordable solution was based on 10 lanes of 10Gbps. However as expected, improvements in technology has allowed higher performance and higher density. Hence the development of the CFP2 and CFP4 specifications. While 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 interchangable (but would be interoperable at the optical interface with approriate connectors).

About CXP
CXPCXP is targeted at the clustering and high-speed computing markets, so we usually called it high-density CXP. Technically, the CFP will work with multimode fiber for short-reach applications, but it is not really optimized in size for the multimode fiber market, most notably because the multimode fiber market requires high faceplate density. The CXP was created to satisfy the high-density requirements of the data center, targeting parallel interconnections for 12x QDR InfiniBand (120 Gbps), 100 GbE, and proprietary links between systems collocated in the same facility. The InfiniBand Trade Association is currently standardizing the CXP.

The CXP is 45 mm in length and 27 mm in width, making it slightly larger than an XFP. It includes 12 transmit and 12 receive channels in its compact package. This is achieved via a connector configuration similar to that of the CFP. For perspective, the CXP enables a front panel density that is greater than that of an SFP+ running at 10 Gbps.

Typical applications of CXP in the data center include 100GE over Copper (CXP): 7m (23ft) and 100GE over multimode fiber: CXP for short reach applications (CFP is used for longer reach applications).

What’s the Difference Between CFP and CXP?
Despite having a similar acronym and emerging at roughly the same time, the CFP and CXP form factors are markedly different in terms of size, density, and intended application. The CFP and CXP optical transceiver form factors are hot pluggable, both feature transmit and receive functions, and both support data rates of 40 and 100 Gbps. But the similarities begin and end there. Aimed primarily at 40- and 100-Gigabit Ethernet (GbE) applications, the CFP supports both singlemode and multimode fiber and can accommodate a host of data rates, protocols, and link lengths. The CXP, by contrast, is targeted at the clustering and high-speed computing markets. The two are therefore complementary, not competitive, according to several sources. Thus, the existence of CXP does not mean the replacing of CFP.

However, things are never black and white. In some case, there is a competition between CFP and CXP, as CFP can also be used with multimode fiber. It becomes more of a choice for system vendors. Do they need to build a box that can adapt to any interface? If so, they would probably use CFP. If it’s a box that is just focused on the short-reach market, then they would probably use something more like CXP.

I hope this post will let you more understanding the 100GbE transceivers, whether CFP or CXP. Similarly, you could kown the 40GbE transceiver through this post as the CFP and CXP also support the 40GbE. If you want to have a further study on this subject, I suggest you to learn the related refference of MSA.

Article Source: http://www.fiber-optic-transceiver-module.com/whats-difference-between-cfp-and-cxp-transceivers.html

Ultra-High-Power Optical Amplifier for FTTH – EYDFA

Background

While the Cable Modem, xDSL, and other forms of broadband access are booming in recent years, Fiber To The Home (FTTH) access is also gradually becoming a project that people are very interested in. The FTTH will eventually realize the “three networks in one” of Telephone, CATV and Internet, when the speed of data transmission can be more than 100 Mbps (200 times faster than the commonly used dial-up Internet access) and bring homes high-definition TV movies and fast online office, etc. FTTH can also solve the problem such as the quality of phone calls, the definition of television and so on.

From the perspective of the world’s situation, the FTTH’s promotion of South Korea and Japan has entered a rapid growth period; North America and Europe has begun to start which brings an optimistic outlook; China, Russia, India and South America is following and speeding up the development. From the perspective of FTTH, the optical communications industry market’s growth potential is still very large.

Applications of High-Power Optical Amplifiers

High-power optical amplifier as one of the basic devices of modern optical communications, is not only the premise of the existence of large-capacity and long-distance all-optical communication networks, but also plays a more and more important role in the process of fiber optic networks’ constantly extending and expanding. At present, in the central office, it usually needs to install more than one optical amplifiers in order to cover larger scope and more users. To take CATV for example, if a medium-sized county needs to send high-quality first-level TV signals to the villages and towns, it generally needs 4 to 8 sets of optical amplifiers. However, if high-power optical amplifiers are used, then only one is enough, which can greatly reduce the cost.

Solutions of High-Power Optical Amplifiers

Traditional Solution using EDFA Technology

One of the solutions for high-power optical amplifiers is to use the traditional general EDFA technology. As shown in the figure below, the signal is amplified at the first stage and then divided into several parts into several EDFAs at the second stage to realize the further ascension of power. The power enlarged in the end can be allocated.

Traditional High-Power Solution using EDFAs

Theare are mainly four problems of this solution:

  • The adoption of multilevel structure will make the optical structure very complex, and due to the adoption of multiple lasers in the internal part, the corresponding control scheme is very complicated.
  • As the multilevel structure has a WDM between the two stages of optical amplifiers, equivalent to bring more insertion loss to the optical path, the noise figure of EDFA amplifiers will deteriorate.
  • In addition, the traditional EDFAs use single mode fiber core pump technology, but high-power single-mode pumped lasers have been greatly restricted on technical and cost.
  • The whole sets of EDFA’s cost is very high and is very expensive.

Better Solution using EYDFA Technology

This ultra-high-power amplifier technology is a multimode cladding pump technology—EYDFA technology, a recently developed new technology that uses the Yb3+ and Er3+ ions doped double-clad fiber. The technology results to the combination of a series of new technologies, new processes and new materials. It is the core technology of ultra-high-power amplifiers and represents the development direction of optical amplifier technologies. While traditional EDFA use single-mode fiber core pump technology to achieve higher output power (which has been greatly limited on the technical and cost), the Er/Yb-Doped Fiber Amplifier (EYDFA) multimode cladding pump technology is the best choice for large output power optical amplifiers. Here is a typical optical structure of EYDFA.

EYDFA Structure

The main advantages of EYDFA are as following:

  • Compared with the single mode fiber core pump technology, multimode cladding pump technology has obvious advantages. The multimode cladding pump technology is to input the pump light to the multimode double-cladding fiber whose cross section are hundreds to thousands of times the single-mode fiber. As a result, at the same input optical density, multimode cladding pump can allow hundreds to thousands of times the single-mode pumped input, easily realizing the optical amplifiers’ high output power or ultra-high output power.
  • Can be realized using a simple optical structure, so the application form is very simple (as shown in the figure below).EYDFA Application Structure
  • The overall cost of the pumps can be greatly reduced.

Fiberstore’s high-power optical amplifier module type products—FTTH-EYDFA series are featured with high output power (17–26 dBm), low noise figure (less than 6 dB @ 1550 nm, 5 dBm input power), wide range of working wavelength (1540–1565 nm), flexible control, high reliability, etc. The output power of high-power optical amplifier is nearing 32 dBm in the laboratory.

Conclusion

Predictably, the widely applications of the ultra-high-power optical amplifiers (EYDFA) will have a profound impact on the development of optical communication, and its market prospect and effectiveness to economic and social present a good trend.

Article Source: http://www.fs.com/blog/ultra-high-power-optical-amplifier-for-ftth-eydfa.html