Application of Fiber Transceiver in Fiber-optic communication
Data transmission distance primarily governs the choice of fiber optic transceiver type and optical fiber. When working with distances up to 2 km, use multimode optical-fiber cable. Singlemode optical-fiber cable, however, is more bandwidth-intensive and has less potential for modal dispersion and noise than multimode optical-fiber cable, translating to the ability to transmit beyond the distance limitations of multimode. Achieving long distance transmission with fiber optic transceivers is not difficult with the proper network tools. Single strand fiber solutions are the simplest way to long distance transmission. In this page we will introduce the application of fiber optic transceiver in the network construction progress which combines with this experience.
Use Optical Transceivers Rather Than Copper for Shorter Distance Applications
Copper SFPs provide a high-speed RJ45 data connector interface for unshielded, twisted-pair copper cable. The 1000BASE-T copper SFP allows a maximum link distance of up to 100 m. For 1Gbps Cisco SFP modules, if the optical transmission distance is less than 275 metres, multimode or single-mode optical fibre and any type of transceiver (figure shown below is a Cisco GLC-SX-MM OEM SFP) can be used. If the transmission distance is between 275 and 500 metres, 50/125-micron multimode or single-mode optical fibre and any type of transceiver can be used.
Use Single- module SFP Transceivers for Long Distance Fiber Network Applications
If the transmission distance exceeds 500 metres, only single-mode optical fibre and a long wave laser transceiver can be used. With the IEEE802.3ae tandard, seven new media types were defined for LAN, metropolitan area network and wide area network connectivity:
- 1000BASE-SX SFP for Multimode Fiber Only – link lengths up to 550m
- 1000BASE-LX/LH SFP for Both Multimode and Single-Mode Fibers - link lengths up to 10km on SMF and up to 550m on MMF.
- 1000BASE-EX SFP for Long-Reach Single-Mode Fibers - link lengths up to 40km.
- 1000BASE-ZX SFP for Long-Reach Single-Mode Fibers - link lengths up to 70km.
Use Dual-rate Optical Transceivers for Long-Reach Fiber Network Applications
The dual-rate SFP is interoperable with the IEEE 100BASE-LX and 1000BASE-LX/LH standards. In a dual-fiber single network configuration, it takes a group of fiber optic transceivers to achieve the desired electrical signal and light signal. When fiber optic transceivers are arranged in a group, they may exchange electrical signals and light signals. Fiber optic transceiver ports can be configured in adaptive mode.
Use 1000BASE-BX10 SFPs for Single-Fiber Bidirectional Applications
As we known, the 1000BASE-BX-D and 1000BASE-BX-U SFPs, compatible with the IEEE 802.3ah 1000BASE-BX10-D and 1000BASE-BX10-U standards, operate on a single strand of standard SMF. The1000Base-BX10 specification provides single-mode, single fiber support at a signaling speed of 1250 Mbps for a span of 10 km or greater depending on fiber type. The two wavelength ranges employed are:
- Downlink at 1480 to 1500 nm
- Uplink at 1260 to 1360 nm
Single-mode fiber enjoys lower fiber attenuation than multimode fiber and retains better fidelity of each light pulse, as it exhibits no dispersion caused by multiple modes. Thus, information can be transmitted over longer distances. Like multimode fiber, early single-mode fiber was generally characterized as step-index fiber meaning the refractive index of the fiber core is a step above that of the cladding rather than graduated as it is in graded-index fiber. Modern single-mode fibers have evolved into more complex designs such as matched clad, depressed clad, and other exotic structures.
Originally published at www.sfp-transceiver-modules.com
Tips of Installing Allied Telesyn SFP Module
AT-SPSX Overview
The Allied Telesis AT-SPSX SFP is a hot pluggable 1000BASE-SX SFP Transceiver module. It is capable of reaching a maximum operating distance of up to 500 m and transmits using an 850 nm wavelength. The AT-SPSX SFP uses a fiber optic cable with LC connectors. The AT-SPSX SFP transceiver is designed to be used in ATI products such as the AT-8000 and AT-9400 series switches.
AT-SPLX10 Overview
The AT-SP10LR is a hot pluggable 10Gbps small form factor transceiver Module. It is compliant with the SFF-8431 SFP+ Electrical Multi-source Agreement (MSA) with five digital monitoring functions: Temperature, Vcc, Tx optical power, Tx laser bias current and Rx received optical power. The Allied Telesyn 10GBASE-LR SFP uses a fiber optic cable with LC connectors.
The AT-SPLX10 SFP transceiver is capable of reaching a maximum operating distance of up to 10 km and transmits using a 1310 nm wavelength. The AT-SPLX10 transceiver is designed to be used in ATI products such as the AT-8000 and AT-9400 series switches.
Specifications
| Model | Wavelength | Operating Temperature | Maximum Distance | Type of Fiber Optic Cable |
|---|---|---|---|---|
| AT-SPSX | 850nm | -5°C to +70°C | 500 m | 50/125 μm multimode fiber |
| 300 m | 62.5/125 μm multimode fiber | |||
| AT-SPLX10 | 1310nm | -5°C to +70°C | 10 km | 9 μm single-mode fiber |
Common Features
- Compact size
- Flexible architecture
- Hot swappable
- RoHS compliant
- Compliant to SFP+ Electrical MSA SFF-8431
- Compliant with SFF-8472 MSA
- Standard LC duplex fiber-optic connector
- Operating Temperature : -5°C to +70°C
- Power Dissipation < 1.3W
- with DOM (Digital optical monitoring)
The SFP Transceiver is a Class 1 laser product, so please do not stare into the laser beam. Keep in mind that a transceiver must be connected to another transceiver or fiber optic which has similar operating characteristics. If you want to hot swap the SFP transceiver, there is no need to power off the networking device when you install or replace an SFP transceiver.
Installing an Allied Telesyn SFP Transceiver
Tips: Before installing a SFP transceiver, you must be sure to observe all standard electrostatic discharge (ESD) precautions, such as wearing an antistatic wrist strap, to avoid damaging the device.
To install an Allied Telesyn SFP or SFP+ transceiver, perform the following procedure:
- Remove the transceiver from the shipping package and store the packaging material in a safe place.
- Slide the transceiver into the SFP slot. If you are connecting the fiber optic cable to the SFP at this time, continue to step 3. Otherwise, stop here.
- Remove the dust cover.
- Connect the fiber optic cable to the transceiver.
Fiberstore can offer OEM AT-SP series and AP-SP10 series with 100% compatibility, and these SFPs offer the latest industry standard in flexible, full-duplex Ethernet connectivity. These hot-swappable, fiber, interfaces simply plug into an SFP/SFP+ slot on Allied Telesis products that are SFP/SFP+ compatible. Configurations can be optimized to meet varied distance and service requirements.
Originally published at www.sfp-transceiver-modules.com
Fiber-Optic Cabling Connectivity for 40Gbps QSFP+
The data center is one of the most critical and dynamic operations in any business. As companies produce, collect, analyze and store more data, IT infrastructures need to grow as well to keep up with the demand. The speed of data center now is increasing to 40 Gbps and eventually to 100 Gbps. Thus, new optical technologies and cabling infrastructure are required. Now let's see some commonly used fiber cabling connectivity options for 40Gbps QSFP+ optics.
40G QSFP+ Optical Modules
As we know, fiber optical transceiver is an electronic device that receives an electrical signal, converts it into a light signal, and launches the signal into a fiber. It also receives the light signal, from another transceiver, and converts it into an electrical signal. Optical transceivers are becoming smaller, but more powerful, which makes them an important piece in server technology. It is the key component in fiber optic transmission. The basic interface of 40G QSFP+ transceiver modules are 40GBASE-LR4 and 40GBASE-SR4 in QSFP+ form factor.
40GBASE-LR4 QSFP+: 40GBASE-LR4 transceiver support with a link length up to 10 kilometers over 1310 nm single mode fiber, LC Connector. It is most commonly deployed between data-center or IXP sites with single mode fiber.
40GBASE-SR4 QSFP+: 40GBASE-SR4 transceivers are used in data centers to interconnect two Ethernet switches with 8 fiber parallel multimode fiber OM3/OM4 cables. It can support the transmission distance up to 100 m with OM3 fiber and 150 m with OM4 fiber. The optical interface of 40GBASE-SR4 QSFP+ is MPO/MTP.
40GBASE-LR4 PSM QSFP+: 40G LR4 Parallel Single Mode (PSM) transceivers which are used to provide support for up to four 10Gbps Ethernet connections on a QSFP+ port over single mode fiber at distances up to 10 km.
40GBASE Extended SR4 QSFP+: Designed with optimized VCSEL with better performance of RMS spectral width compared with QSFP+ SR4. QSFP+ extended SR4 transceivers can support transmission distance up to 300 m with OM3 fiber and 400 m with OM4.
Passive & Active DAC
The QSFP+ passive or active direct attach copper cables are designed with twinax copper cable and terminated with QSFP+ connectors. The main difference between passive QSFP+ DAC and active QSFP+ DAC is that the passive one is without the active component. They provide short distance (same shelf) inexpensive connectivity at up to 40Gbps rates and operate 4 independent 10G channels using the QSFP connector footprint. Each of the four channels can operate at multi-rate speeds Gigabit to 10Gbps.
Active Optical Cable (AOC) Assemblies
Active optical cable, namely AOC brings a more flexible cabling than direct attach copper cables with the advantages of lighter weigth, longer transmission distance and higher performance for anti-EMI. Now, 40G AOC assemblies are popular with users.
After introducing the basic options of 40G cabling connectivity, we take a conclusion for the above content in the following tables:
| Options | Advantages | Disadvantages |
|---|---|---|
| 40G QSFP+ Optical Modules | Allows extended-reach capabilities; cable links and optical engines are separate and thus can be upgraded independently. | More expensive than other short-reach direct-attach options. |
| Passive & Active DAC | Allows lower-cost short-reach capability; typically used for top-of-rack (TOR)-to-server connectivity. |
Limited to 5m (passive) to 10m (active), and coaxial cable can be stiff and bulky in high-density deployments. |
| Active Optical Cable Assemblies | Allows lower-cost short-reach capability with more flexible cabling; typically used for ToR-to server connectivity. | Limited to less than 10m; reconfigurations of length or failed transceiver requires replacement of entire assembly. |
In addition, don't forget there are some typical cabling components you will require when building 40G cabling, such as MTP fiber cables, MPO cables, MTP cassettes, LC to MTP jumpers and so on. The existing MTP-LC modules that were used in the two-fiber serial transmission would be replaced with MTP conversion modules for parallel optics. 40G optical modules and cabling components are some of the little things that definitely can make a big difference in cabling connectivity.
Optical Transceiver Transition From 40G to 100G for Data Center
Optical transceivers always play an important role in the modern data center. And their importance will continue to grow in the following years. The modern data centers usually have 10G access ports that interface to 40G switching fabrics. However, the 25G access ports and 100G switching fabrics will be propelled soon. Actually, one key factor to decide the applications of optical transceivers in data center is form factor.
Nowadays, the data center have consolidated around optical transceivers in the SFP form factor for server access and around QSFP transceivers for switch-to-switch interconnects. Moreover, when the distance to the access port is less than 5 meters, direct attach copper cables are usually utilized while active optical cables are used for longer distances.
SFP+ transceivers play an important role in 10G transmission. SFP+ transceivers have the advantages of compactness, high performance and cost savings and are widely used in 10G access ports. But this situation will be changed when the access speed increases to 25G and the 10G access ports turn to SFP28. Besides, the ecosystem around 25G lanes will be expected to leverage in application such as next-generation enterprise networks that will drive demand for SFP28 modules operating over single-mode fiber for reaches of 10 km to 40 km.
QSFP transceiver is a parallel transceiver, because it is able to accept 4 electrical input lanes, and operate at 4 x 10 Gbps. At present, 40G QSFP+ transceivers are widely deployed in data center switching fabrics and ramping up hard as data centers deploy 40GbE, especially as a high-density 10G interface via breakout cables. However, a research said that QSFP28 transceiver modules will be deployed in large quantities as data centers transition from 40G to 100G switching fabrics starting in 2016. What is QSFP28? It is well known that the first-generation QSFP optical transceivers are equipped with four Tx and Rx and each channel has a rate of 10 Gbps. With the development of technology, now each channel of QSFP transceiver is able to transmit and receive data up to 28 Gbps. Such kind of transceiver is called QSFP28 . It is a new trend for 100G applications.
The first optical transceivers shipped with 100G transceivers were CFP which supports 100 Gbps and 10 x 10G lane electrical interface defined in 802.3ba. But CFP2 soon came along and achieved 5 x 25G or 10 x 10G lane electrical interface with reducing the form factor by half of CFP. But it is too expensive and the footprint is too large to trigger mass deployment. CFP4, half the size of CFP2 has been launched after CFP2. At the same time, QSFP28 is competing with it. Currently, CFP4 and QSFP28 seem to be neck and neck. CFP4 has higher maximum power consumption giving it the advantage on longer reach optical distances while QSFP28 has higher density. In addition, in data center, there is another trend that nearly all link lengths are less than 2km. Thus for intra-connection and the aggregation switch design, QSFP28 transceivers which have almost the same size of QSFP+ seem to be a superior choice for data center applications although there are still some technical issues of QSFP28 waiting to be solved.
If you are going to have your data center converted to 40G or 100G, Fiberstore is a good place to select optical transceivers. Fiberstore offers comprehensive solutions for optical transceivers that meet the needs of 1G to 100G applications.
Reference: How Will Fiber Optic Transceivers Evolve for Future Data Centers
OTDR Basis
With the development of technology, more and more fiber tools are available. They are used for testing at different stages of the network to meet various test requirements. These tests are used to reveal the total loss, optical return loss and fiber length, and the tests can be in a complete network or in a single fiber. Besides, the test may require further examination of the different elements of the measured link. Whether find fault in the network, or identify the characteristics of each component in the link, or locate potential problems for a fiber, all these will need to use optical time domain reflectometer (OTDR). OTDR is the ideal choice from commissioning to the optical network troubleshooting and maintenance.
OTDR is an optoelectronic instrument used to characterize an optical fiber. An OTDR is the optical equivalent of an electronic time domain reflectometer. It injects a series of optical pulses into the fiber under test and extracts, from the same end of the fiber, light that is scattered (Rayleigh backscatter) or reflected back from points along the fiber. The scattered or reflected light that is gathered back is used to characterize the optical fiber. This is equivalent to the way that an electronic time-domain reflectometer measures reflections caused by changes in the impedance of the cable under test. The strength of the return pulses is measured and integrated as a function of time, and plotted as a function of fiber length.
During the process of OTDR testing, the instrument inject a higher power laser or fiber optic light source pulse into a fiber from one end of the fiber cable at the OTDR port to receive the return information. When the optical pulse is transmitted through the fiber, there will be a scattered reflection. Part of the scattering and reflection will return to the OTDR. Useful information returned will be measured by he OTDR detector, and act as the time or curve segments of fibers at different positions. By recording the time used of the signals from transmission to returning, the transmission speed of the light in the glass fibers, the distance can be calculated.
The major advantage of the OTDR is that tests can be done from one end of the link and you do not have to access to the other end. This means that you don’t need two people to do the test and then save the problems of coordinating between people. Besides, it is much quicker for the testing. So even simple tests which could be performed with a basic optical source at one end of the link and a power meter at the other are often performed with an OTDR.
Many modern OTDRs come with additional functions such as optical power meter or laser source so that a good OTDR often has all of the function needed by a technician in the field. Moreover, many OTDRs offer computer output so that you can collect OTDR data in the form of digital readings and analyze it later on a computer. FS.COM has many kinds of OTDRs at reasonable price. If you are looking for an OTDR, FS.COM is an excellent option.
Related article : OTDR, LTS and Source&Meter: Which Is Better for You?
Reference: https://en.wikipedia.org/wiki/Optical_time-domain_reflectometer
Buy Compatible Cisco Transceivers for Your Network
Cisco, established in 1984, is an international reputable company providing internet solutions, equipment and software products. It is also specialized in producing transceiver modules. Transceiver modules are widely applied to wireless communication devices. Deploying a Cisco transceiver module for your network is a best option for Gigabit Ethernet connection or fibre channel. Cisco transceivers have many advantages.
First, Cisco transceivers are of good scalability. Scalability means the inherent or potential capacity to rise beyond eight channels on one stand, which makes organizing and managing a network more easier.
Second, it is more simple and easy for Cisco transceivers to make the configuration. Configuration is able to lead the resources being depleted when an excess amount of time is taken in carrying out the process. The resources here can be in the form of a professional at work or any other monetary expenses as well. So using a Cisco transceiver can help to save your resources and cost. It brings benefit to you eventually.
Third, Cisco transceivers are considered to be the most reliable and capable forms of pluggable modules available and they are very suitable for large offices and organizations. We are living in a world full of various technology. Everyone needs to ensure that they are in control and connected. So having a system in place is essential and efficient. Cisco has the parts and system you require, and also it has excellent technical support. Thus choosing Cisco transceivers with a professional support team can help your network to back up and run quickly.
Fourth, a large selection of Cisco transceivers for different applications could be chosen. For instance, Cisco 100 Gigabit modules, Cisco 40 Gigabit modules, Cisco 10 Gigabit modules, Cisco CWDM/DWDM transceiver modules all can ensure the same prominent performance. You can choose the suitable one for your network.
Fifth, it is available for you to rent the transceivers from Cisco, which allows you to have a full technical support package. So it is a good choice to utilize Cisco transceivers for your Ethernet solutions, moreover, Cisco Transceivers are able to be used in conjunction with other pieces of equipment.
From above description, we could confirm that Cisco transceivers are so excellent, but original Cisco transceivers are very expensive. Buying compatible Cisco transceivers from other manufacturers would be a good choice, such as Fiberstore. Fiberstore has various cost-effective standards-based compatible Cisco transceivers, such as GLC-LH-SMD, SFP-GE-S, GLC-FE-100LX, etc. Buy a compatible Cisco transceiver for your network and then improve your network performance.
Related article: Introduction to Cisco SFP Modules for Gigabit Ethernet
Related article: A Cost-effiective Solution – Cisco Compatible SFP
How Are Optical Transceivers Classified?
Optical transceivers can be classified into different categories based on the performance characteristics and nature. The most common characteristics include: transfer rate, transmission distance, fiber mode, wavelength, connector type. This article will have an explanation of the criteria used to classify optical transceivers.
Transfer Rate
Optical transceivers are classified based upon the data transfer rates. The commonly used rates are 10GBASE, 40GBASE, 100GBASE, 1000BASE and 100BASE. The rates mean the speed at which an optical transceiver can transmit data over Ethernet. So 10GBASE refers to 10 Gigabits per second. 40GBASE means 40 Gigabits per second. 100GBASE means 100 Gigibits per second. 1000BASE refers to 1 Gigabit per second, while 100BASE means 100 Megabits per second. According to these rates, fiber optic transceivers have 1000BASE-T SFP, 40G transceiver, 100G transceivers, etc.
Transmission Distance
Optical transceiver cannot transmit data the same distance. For example, a single-mode transceiver is able to transmit distances from 20 km to 120 km, while a multimode transceiver can transmit 2 km to 5 km. Single-mode transceiver supports long distance transmission. Multimode transceiver is generally classified as short reach.
Fiber Mode
By the mode of fiber, there are two types of transceiver: single-mode transceiver and multimode transceiver. Single-mode fiber allows only a single mode of light to couple into the core. This eliminates the modal dispersion issue. Multimode fiber allows multiple modes of light to couple into the fiber. This type of multimode-specific dispersion severely limits the transmission distance achievable over multimode fiber as contrasted with single-mode fiber.
Wavelength
Infrared light is used to transmit data over fiber optic networks. The wavelength refers to the measurement of the distance between successive crests in the light wave. Optical transceivers transmit data at one wavelength. The three primary wavelengths are 850 nm, 1310 nm and 1550 nm. Single-mode fiber is optimized for 1310nm and 1550nm wavelengths, while multimode fiber is designed to operate at 850nm and 1300nm wavelengths.
Connector Type
Optical transceiver can be classified into different categories based upon the connector types. The mainly used connectors with fiber optic transceivers include LC, SC, ST and MPO. These connector types generally follow a color code system to differentiate between connectors compatible with single-mode and multimode fiber. For example, a MPO connector will be used in QSFP transceivers.
When you call for an optical transceiver, these classification criteria will be useful. They will help to select the proper transceiver for your application. If the proper classification is not chosen, the device may fail prematurely and become unreliable. In order to avoid undesirable outcomes, please always be familiar with the classification of optical transceiver. Fiberstore has various fiber optic transceivers such as SFP transceiver, copper SFP transceiver, DWDM SFP, CWDM SFP, etc. It is an excellent option for you.
