Cloud Computing vs Big Data: What Is the Relationship?

Cloud computing and big data are two of the most trending terms in the ever-lasting IT sector nowadays. You may think that they both do the same thing but actually, both of them have their own ways to work to perform. Cloud computing vs big data, what are they? What is the relationship between them?

cloud computing vs big data

Cloud Computing Tutorial

Cloud computing is a technology used to store data and information on a remote server rather than on a physical hard drive. It uses the servers hosted on the Internet to store, manage, and process data, rather than a local server or a personal computer. It means accessing resources of organization from any remote location in the world. In simple term accessing RAM, HDD, Processor of organization’s server from laptop, desktop from any of the location where Internet is available.

what is cloud computing with example

As shown in the figure above, cloud computing is collection of different services, providing services to end user via the Internet. Services like storage, virtual desktop applications, Web/App hosting process power from servers. In the following architecture, the infrastructure built to provide services is called cloud computing. This infrastructure from where the services gets accessible is front end.

Big Data Wiki

The term big data is very popular nowadays, representing huge sets of data that can be further processed to extract information. Big data carries hidden patterns and algorithms which are unlocked by using various tools available in the market. These data sets are further analyzed to provide business insights. Big data is all about storing and processing of data that is exponentially growing these days. Giants like Google, Facebook are having their own data centers to keep track and to secure their users’ data. That’s also why many big companies are equipped with reliable network equipment (including the server, router or fiber switch) for data storage or traffic forwarding in their data centers. For high performance and cost-effective enterprise routers, Gigabit Ethernet switch and 10gbe switch, FS is a case in point.

what is big data technology

Big data requires a large amount of storage space. While the price of storage continued to decline, the resources required to leverage big data can still pose financial difficulties for SMBs (small to medium sized businesses). A typical big data storage and analysis infrastructure will be based on clustered network-attached storage (NAS). Clustered NAS infrastructure requires configuration of several NAS pods with each NAS pod comprised of several storage devices connected to an NAS device. The series of NAS devices are then interconnected to allow massive sharing and searching of data.

Key Comparisons Over Cloud Computing vs Big Data

The cloud computing works in a consolidated manner, while the big data comes under the technology of cloud computing. The crucial difference between cloud computing vs big data is that cloud computing is used to handle the huge storage capacity to provide various flexible and techniques to tackle a magnificent amount of the data. While big data is the information processed with cloud computing platform. The following chart gives a more detailed comparison over cloud computing vs big data.

Cloud Computing Big Data
Basic On-demand services are provided by using integrated computer resources and systems. Extensive set of structured, unstructured, complex data forbidding the traditional processing technique to work on it.
Purpose Enable the data to be stored and processed on the remote server and accessed from any place. Organization of the large volume of data and information to the extract hidden valuable knowledge.
Working Mode Distributed computing is used to analyse the data and produce more useful data. Internet is used to provide the cloud-based services.
Benefits Low maintenance expense, centralized platform, provision for backup and recovery. Cost effective parallelism, scalable, robust.
Challenges Availability, transformation, security, charging model. Data variety, data storage, data integration, data processing, and resource management.

Cloud Computing vs Big Data: They Work Hand in Hand

Both cloud computing and big data are good at their marks. Cloud computing vs big data: they differ from each other but work hand in hand. They are the perfect combination for data storage and processing. The cloud computing has been a precursor and facilitator to the emergence of big data. If big data is the content, then cloud computing is the infrastructure.

Originally published at http://www.fiber-optic-tutorial.com/cloud-computing-vs-big-data-relationship.html

 

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VLAN Configuration Guidelines on Layer 3 Switch

As networks grow larger and larger, scalability becomes an issue. Every device in the network needs to send broadcasts to communicate in a broadcast domain . As more devices are added to the broadcast domain, more broadcasts start to saturate the network. In this case, VLAN (Virtual LAN) is needed to separate broadcast domains virtually, eliminating the need to create completely separate hardware LANs to overcome this large-broadcast-domain issue. In this post, we’re gonna expound the motivators to deploy VLAN and how to set up VLAN configuration step by step.

VLAN Configuration

Motivators to Implement VLAN

VLAN is a way of creating multiple virtual switches inside one physical data switch. There are a lot of reasons to implement VLAN, some of which are listed as follows.

  • Link Utilization: Link utilization is another big reason to use VLANs. Spanning tree by function builds a single path through your layer 2 network to prevent loops. If you have multiple redundant links to your aggregating devices then some of these links will go unused. To get around this you can build multiple STP topology with different VLANs.
  • Service Separation: If you have IP security cameras, IP Phones, and Desktops all connecting into the same switch it might be easier to separate these services out into their own subnet. This would also allow you to apply QoS markings to these services based on VLAN instead of some higher layer service. You can also apply ACLs on the device performing Layer 3 routing to prevent communication between VLANs that might not be desired.
  • Subnet Size: If a single site becomes too large you can break that site down into different VLANs which will reduce the number of hosts that see need to process each broadcast.

VLAN Configuration Guidelines on Layer 3 Switch

Configuring two or more VLANs to communicate with each other requires the use of either a VLAN-aware router or a Layer 3 switch. VLAN configuration can be accomplished either in CLI interface or in Web interface. The following video is a VLAN configuration example on FS S5800/S5850 10 gigabit switch.

Configure VLAN in CLI (command-line interface)

Here we take FS S5850-32S2Q Layer 3 switch as an example to configure VLAN. To create a VLAN via CLI interface, SecureCRT software is required to enter CLI interface, then perform the VLAN configuration command in the chart below:

Procedure Command Purpose
Step 1 Set the parameters of COM2 port Quick connect on startup
Step 2 #enter Enter CLI interface
Step 3 #configure terminal Enter the global configure mode
Step 4 #vlan database Enter VLAN configure mode
Step 5 #show vlan all Check the details of all VLANs on the switch
Configure VLAN in Web Interface

Configuring VLAN in Web Interface is quite simple. Just perform the following two steps and you would see the basic info of the VLAN that is created.

Step 1: Log in the Web user interface using the account and password

Step 2: Find the service management and create a new VLAN, and set its ID as 10 or 20.

Note: Ports configured to use VLAN 10 act as if they’re connected to the exact same switch. Ports in VLAN 20 can not directly talk to ports in VLAN 10. They must be routed between the two or have a link that bridges the two VLANs

Summary

VLAN deployments make it easy for network engineers to partition a single switched network to match the functional and security requirements of their systems without having to run new cables or make major changes in their current network infrastructure. The proper VLAN configuration on Layer 3 switches ensures reliable and secure data link access to all hosts connected to switch ports. Knowing more about VLAN configuration would allow you to use them when you need them and to use them correctly when you do.

Source: http://www.fiber-optic-tutorial.com/vlan-configuration-guidelines-layer-3-switch.html

Do I Need a Gigabit Switch or 10/100Mbps Switch?

Ethernet network speeds have evolved significantly over time and typically range from Ethernet (802.11) at 10Mbps, Fast Ethernet (IEEE 802.3u) at 100Mbps, Gigabit Ethernet (IEEE 802.3-2008) at 1000Mbps and 10 Gigabit Ethernet (IEEE 802.3a) at 10Gbps. Meanwhile, Ethernet switches have also escalated from 10/100Mbps switch to Gigabit switch, 10GbE switch, and even 100GbE switches. The topic came up frequently that “Do I Need a Gigabit Switch or 10/100Mbps Switch?” Gigabit switch vs 10/100Mbps switch, which do I need to satisfy my network speeds requirement? This post will give you the answer.

Ethernet Speed

Gigabit Switch: the Mainstream on Network Switch Market

A Gigabit switch is an Ethernet switch that connects multiple devices, such as computers, servers, or game systems, to a Local Area Network (LAN). Small business and home offices often use Gigabit switches to allow more than one device to share a broadband Internet connection. A gigabit switch operates in the same manner, only at data rates much greater than standard or Fast Ethernet. People can use these switches to quickly transfer data between devices in a network, or to download from the Internet at maximum speeds of 1000Mbps. If a switch says “Gigabit”, it really means the same thing as 10/100/1000, because Gigabit switches support all three speed levels and will auto-switch to the appropriate one when something is plugged in. The following is a Gigabit 8 port poe switch with 8 x 10/100/1000Base-T RJ45 Ethernet ports.

8 port poe switch

10/100Mbps Switch: Still Alive and Well for Some Reason

10/100Mbps switch is a Fast Ethernet switch released earlier than Gigabit Ethernet switch. The data speed of 10/100Mbps switch is rated for 10 or 100Mbps. When a network switch says “10/100”, it means that each port on the switch can support both 10Mbps and 100Mbps connection speeds, and will usually auto-switch depending on what’s plugged into it. Currently, few devices run at 10Mbps, but it is still alive on the market for some reason. Actually, 10/100 is sufficient for internet browsing and Netflix. But if you will be doing more than one thing with your network connection, such as file transfers, or the set-top box, I would recommend you go with the Gigabit switch.

10/100Mbps Switch

Gigabit Switch vs 10/100Mbps Switch: How to Choose?

Network engineers who refresh the edge of their campus LAN encounter a fundamental choice: Stick with 100Mbps Fast Ethernet or upgrade to Gigabit Ethernet (GbE). Vendors will undoubtedly push network engineers toward pricier GbE, but network engineers need to decide for themselves which infrastructure is right for the business. Currently, Gigabit switch is much more popular than Fast Ethernet 10/100Mbps switch. Because gigabit switch used in tandem with a gigabit router will allow you to use your local network at speeds up to ten times greater than 10/100Mbps switch. If either of these component are not gigabit, the entire network will be limited to 10/100 speeds. So, in order to use the maximum amount of speed your network can pump out, you need every single component in your network (including you computers) to be gigabit compliant. In addition, by delivering more bandwidth and more robust management, Gigabit switches are also more energy efficient than 10/100Mbps switches. This offers enterprises the opportunity to lower their power consumption on the network edge.

Conclusion

There’s a multitude of switch options to choose from on the dazzling market. So, before determining the right switch for your network, you’re supposed to have a close look at your current deployment and future needs. But for most cases, we recommend you buy Gigabit Ethernet devices instead of Fast Ethernet devices, even if they cost a little bit more. FS provides a full set of Gigabit switches, including 8 port switch, 24 port switch, 48 port switch, etc. With these high performance Gigabit Ethernet switches, your local network will run faster with better internet speed.

Originally published at http://www.fiber-optic-tutorial.com/gigabit-switch-vs-10-100mbps-switch.html

TAP Aggregation Switch: Key to Monitor Network Traffic

For network professionals, Ethernet switches have already been used very commonly in network design. In order to ensure network security and monitor the performance of the standard Ethernet switches, network test access port (TAPs) have emerged as one of the primary sources for data monitoring or network traffic monitoring. What is network TAP or TAP aggregation switch, and how to deploy it for network traffic monitoring? This post will give you the answer.

What Is TAP Aggregation Switch or Network TAP?

A network tap is a hardware device which provides an approach to access the data flowing across a network. It functions by flow copy or aggregation, thus it’s also called TAP aggregation switch. TAP aggregation switch works by designating a device to allow the aggregation of multiple TAPs and to connect to multiple monitoring systems. In this process, all the monitoring devices are linked to specific points in the network fabric that handle the packets that need to be observed. In most cases, a third party TAP aggregation switch monitors the traffic between two points in the network. If the network between point A and B consists of a physical cable, a network TAP or TAP aggregation switch might be the best way to accomplish this monitoring. TAP aggregation switch deployed between point A and B passes all traffic through unimpeded, but it also copies that same data to its monitor port, which could enable a third party to listen.

Deployment Scenario of TAP Aggregation Switch

TAP aggregation switches or network TAPs can be extremely useful in monitoring traffic because they provide direct inline access to data that flows through the network. The following part illustrates the typical applications of TAP aggregation switches in data center and carrier network.

Application in Data Center
As shown in the figure below, user can enable the timestamp and source port label function of TAP devices. The server cluster can access the exact packet process time in each data center layer via source port and timestamp message carried by the packets. From port1, port2, port3, user can distinguish the devices that the streams come from. Through T1, T2 and T3, packets forward latency of each device can be calculated, according to which users can find out the bottleneck during packet forwarding for the further optimization of data center network.

TAP Aggregation Switch for Data Center

Application in Carrier Network
TAP aggregation switch can also be used to assist DPI (Deep Packet Inspection) in carrier networks. As illustrated below, TAP aggregation switch is applied to forward flows of carrier at internet access point and sends a mirrored copy of the packet flow to DPI device at the same time. The DPI device is for traffic analysis, once a virus on website or illegal information has been monitored, the flows will be blocked by a five elements table sent from management channel between DPI and TAP.

TAP Aggregation Switch for Carrier Network

FS TAP Aggregation Switches Solution

FS network TAPs or TAP aggregation switches deliver security, visibility and traffic analysis for high density, non-blocking 1G/10/40/100GbE networks at any scale with advanced traffic management capabilities for lossless monitoring of network traffic. They can cost-effectively and losslessly monitor all data center network traffic, while capturing and analyzing only the traffic that is needed. The table below lists FS T5800 and T8050 series TAP aggregation switches.

TAP Aggregation
Key Features
  • Standard 1U 19’’ rack mountable, 240 Gbps switching capability
  • 8×10/100/1000 Base-T Ethernet Ports, 8×1000 Base-X SFP Ports (Combo)
  • 12x10GE SFP+ Ports
  • Dual modular power supply
  • Standard 1U 19’’ rack mountable
  • 4x10GE SFP+ Ports(Combo)
  • 20x40GE QSFP+ Ports
  • 4x100GE QSFP28 Ports
  • Dual modular power supply
  • Standard 1U 19’’ rack mountable
  • 48x10GE SFP+ Ports
  • 2x40GE QSFP+ Ports
  • 4x100GE QSFP28 Ports
  • Dual modular power supply
  • Standard 1U 19’’ rack mountable
  • 48x10GE SFP+ Ports
  • 6x40GE QSFP+ Ports
  • Dual modular power supply
  • Standard 1U 19’’ rack mountable
  • 32x10GE SFP+ Ports
  • 2x40GE QSFP+ Ports
  • Dual modular power supply

Conclusion

TAP aggregation switches are crucial to any network monitoring plan because they offer an uncensored view of all network traffic. With FS TAP aggregation switches, customers can transform opaque data center traffic into comprehensive visibility for security threat detection, service availability monitoring as well as traffic recording and troubleshooting. Apart from TAP aggregation switches, the standard Ethernet switches including Gigabit switches, 10gb switches, 40gb switches and 100gb switches are also available for your choice.

Originally published at http://www.fiber-optic-tutorial.com/tap-aggregation-switch-monitor-network-traffic.html

DWDM Solutions for Arista 7500E Series Switches

Nowadays, the deployment of DWDM solution has been hotly debated in many enterprise networks, especially in the new Lay2 and Lay3 equipment like Arista 7500E series switches. For many enterprises, DWDM network solutions are undoubtedly the best choices of action, because they can provide a scalable and elastic solution for the enterprise that offered high bandwidth and data separation. This article will demonstrate DWDM solutions to Arista 7500E switches which are the foundation of two-tier open networking solutions for cloud data centers.

Analysis of DWDM System

DWDM (Dense Wavelength Division Multiplexing) is a technology allowing high throughput capacity over longer distances commonly ranging between 44-88 channels and transferring data rates from 100 Mbps up to 100 Gbps per wavelength. For intra-datacenter solutions, an endpoint connection often uses multimode (850 nm) for short ranges and single mode (1310 nm) for longer ranges. The DWDM node converts this local connection to a channelized frequency or wavelength, which is then multiplexed with other wavelength and transmitted over a single fiber connection.

A key advantage of DWDM is that it’s bitrate independent. DWDM-based networks can transmit data in IP, ATM, SONET, SDH and Ethernet. Therefore, DWDM systems can carry different types of traffic at different speeds over an optical channel. Voice transmission, email, video and multimedia data are just some examples of services which can be simultaneously transmitted in DWDM systems.

DWDM multi-channel Mux/Demux

Arista 7500E 100G DWDM Line Card

With full support for Layer2 and Layer3 protocols, Arista 7500E series switch is the ideal option for the network spine for two tier data centers applications. Arista 7500E especially provides the perfect resolution for high bandwidth Metro and long-haul DCI solutions with the 6-port DWDM line card. It has great advantage to migrate from existing 10G DWDM to 100G coherent line side modules. The 7500E series DWDM line card provides six 100G ports with coherent 100G tunable optics, which enables customers to connect directly into existing WDM MUX module without the need to add transceivers, which can save cost and space to a large extent. The coherent optics use C-band region wavelengths and offer a cost efficient solution for up to 96 channels of 100Gb over a single dark fiber pair.

Use Cases for Arista 7500E DWDM Card
    • Less Than 80 km Dark Fiber Connection
      For distance less than 80 km, Arista 7500E switch with DWDM line cards can directly terminate a dark fiber connection with a pair of passive DWDM Mux, thus achieving a point-to-point connection between two locations.

Dark Fiber Connection

  • Between 80 km and 150 km Connection
    For distance greater than 80 km but less than 150 km, losses occurred during the process of transmission should be considered. In order to boost the power level, an EDFA (Erbium Doped Fiber Amplifier) is used to gain flatness, noise level, and output power, which is typically capable of gains of 30 dB or more and output power of +17 dB or more. With the use of EDFA, the signal can be boosted into a certain power level, thus achieving distances of up to 150 km.
Conclusion

The Arista 7500E series DWDM solution offers a cost-effective solution for transporting scalable and massive volumes of traffic, and enhances the 7500E system by providing high performance 100G DWDM port density with the same rich features and dedicated secure encryption in compact and power-efficient systems. Enterprises can easily migrate existing metro and long-haul DWDM networks to add new 100G capacities, thus expanding Layer2 and Layer3 services.

Originally published at http://www.china-cable-suppliers.com/dwdm-solutions-arista-7500e-series-switches.html

Difference Between AON and PON

AON (Active Optical Networks) and PON (Passive Optical Network) serve as the two main methods of building CWDM and DWDM backbone network. Each of them has their own merits and demerits. This article will compare them according to their different features and applications.

AON

An active optical system uses electrically powered switching equipment, such as a router or a switch aggregator, to manage signal distribution and direction signals to specific customers. This switch directs the incoming and outgoing signals to the proper place by opening and closing in various ways. In such a system, a customer may have a dedicated fiber running to his or her house. The reliance of AON on Ethernet technology makes interoperability among vendors easy. Subscribers can select hardware that delivers an appropriate data transmission rate and scale up as their needs increase without having to restructure the network. However, AON require at least one switch aggregator for every 48 subscribes. Since it requires power, an active optical network inherently is less reliable than a passive optical network.

PON

A PON is made up of an optical line termination (OLT) at the service provider’s central office and a number of optical network units (ONUs) near end users. Typically, up to 32 ONUs can be connected to an OLT. The passive optical network simply describes the fact that optical transmission has no power requirements or active electronic parts once the signal is going through the network.

A PON system makes it possible to share expensive components for FTTH. A PON splitter takes one input and splits it to broadcast to many users, which can lower the cost of the links substantially by sharing, for example, one expensive laser with up to 32 homes. PON splitters are bi-directional, that is signals can be sent downstream from the central office, broadcast to all users, and signals from the users can be sent upstream and combined into one fiber to communicate with the central office.

PON

A passive optical network does not include electrically powered switching equipment. It uses optical splitters to separate and collect optical signals as they move through the network. A PON shares fiber optic strands for portions of the network. Powered equipment is required only at the source and receiving ends of the signal. PONs are efficient since each fiber optic strand can serve up to 32 users. Besides, PONs have a low building cost compared with active optical networks along with lower maintenance cost. However, PONs also have some demerits. They have less range than an AON, which means subscribes must be geographically closer to the central source of the data. When a failure occurs, it is rather difficult to isolate it in a PONs. Moreover, because the bandwidth in a PON is not dedicated to individual subscribers, data transmission speed may slow down during peak usage times in an effect known as latency. And latency would quickly degrade services such as audio and video, which need a smooth rate to maintain quality.

AON vs. PON

As early as the year 2009, PONs began appearing in corporate networks. Users were adopting these networks because they were cheaper, faster, lower in power consumption, easier to provision for voice, data and video, and easier to manage, since they were originally designed to connect millions of homes for telephone, Internet and TV services.

Passive Optical Networks (PON) provide high-speed, high-bandwidth and secure voice, video and data service delivery over a combined fiber network. The main benefits of PON are listed below:

  • Lower network operational costs
  • Elimination of Ethernet switches in the network
  • Elimination of recurring costs associated with a fabric of Ethernet switches in the network
  • Lower installation (CapEx) costs for a new or upgraded network (min 200 users)
  • Lower network energy (OpEx) costs
  • Less network infrastructure
  • You can reclaim wiring closet (IDF) real estate
  • Large bundles of copper cable are replaced with small single mode optical fiber cable
  • PON provides increased distance between data center and desktop (>20 kilometers)
  • Network maintenance is easier and less expensive
  • Fiber is more secured than copper. It is harder to tap. There is no available sniffer port on a passive optical splitter. Data is encrypted between the OLT and the ONT.
Conclusion

To sum up, the PON network’s predefined topology makes individual changes more difficult. By terminating all the fiber optics at the OLT, i.e. the same fiber optic topology as in the AON (point-to-point), this disadvantage can be overcome. Therefore, for future-proof infrastructure investment, reliable point-to-point fiber optics technology should always be considered.

Using EDFA Amplifier for Long-Haul CATV Systems

With Laser technology combining with fiber optic technology, CATV systems in the field of optical communication have demonstrated unprecedented and irreplaceable achievements in the past few decades. When transmitting optical signals with fibers, fiber attenuation is the main factor that limits the transmission distance. EDFA (Erbium-Doped Fiber Amplifier) designed for CATV long-haul transmission avoids the conversion of optic-electric-optic in CATV long-haul transmission. It amplifies low signal power into high signal power, thus extending transmission distance. This post analyzes EDFA configurations and the utilization in long-haul CATV systems.

EDFA Leading Position in CATV Systems

EDFA is one of the most prominent achievements in fiber optic transmission technology over the past decade. Because it cleverly combined the laser technology and optical fiber manufacturing technology in the CATV systems and its applications were then rapidly expanded. Originally PDFA and EDFA amplifiers were equally used for CATV systems, but today, EDFA has completely replaced PDFA and become the primary device for fiber optic transmission systems. Why EDFA has leading position on CATV systems? Because EDFA noise and distortion characteristics are better, and its superior characteristics can be clearly seen in the following:

  • Operates at wavelength of 1550nm, consistent with C-band where fiber has the lowest loss
  • Has higher saturation output power, useful in systems requiring transmission up to 100 km or systems requiring the optical signal to be split to multiple fiber optic receivers
  • The signal gain spectrum is wide up to 30nm or more, can be used for broadband signal amplification, especially for WDM (wavelength division multiplexing) system, ideal for radio and data services networks
  • Has user friendly interface RS232, easy to control and monitor with computers
  • Low noise figure with high stability
EDFA Configurations

The configuration of a co-propagating EDFA is shown in Figure 1. The optical pump is combined with the optical signal into the erbium-doped fiber with a wavelength division multiplexer. A second multiplexer removes residual pump light from the fiber. An in-line optical filter provides additional insurance that pump light does not reach the output of the optical amplifier. An optical isolator is used to prevent reflected light from other portions of the optical system from entering the amplifier.

EDFA Configuration-1

An EDFA with a counter propagating pump is pictured in Figure 2. The copropagating geometry produces an amplifier with less noise and less output power. The counter propagating geometry produces a noisier amplifier with high output power. A compromise can be made by combining the co- and counter-propagating geometries in a bi-directional configuration.

EDFA Configuration-2

A Typical CATV System Using EDFA

Figure 3 illustrates a basic long-haul CATV transmission system designed to carry 77 channels of CATV signals for 100 km in a basic point-to-point configuration.

CATV EDFA

As you can see in Figure 3, the local CATV provider sends 77 channels of CATV signals at the transmitting side. After processing and RF combining, those multiple signals are combined into one channel of CATV signal with the wavelengths of 1550 nm. It transmits over a single-mode optical fiber to 50 km. An EDFA amplifier is used at the middle point to amplify the signals to a certain power level, continuing to transmit over a single mode fiber to 100 km. At the receiving side, the 1550nm CATV channel is split into multiple channels of 1550nm CATV signals, serving multiple hotel cable TV users.

FS.COM CATV EDFA Optical Amplifiers List

EDFA has undoubtedly received wide interest for CATV applications because of its high output power, low distortion and low noise capability. FS.COM supplies optical amplifiers including CATV EDFA, SDH EDFA, DWDM amplifier, etc. The following table lists FS.COM CATV EDFA amplifiers which are available with range of output power from 13 dBm to 24 dBm to meet the requirements of a high-density solution for the large-scale distribution of broadband CATV video and data signals to video overlay receivers in a FTTH/FTTP or PON system.

Product ID Part Number Description
17467 CEDFA-O13 New 13dBm 1550nm CATV EDFA Fiber Optic Amplifier
17489 CEDFA-O17 New 17dBm 1550nm CATV EDFA Fiber Optic Amplifier
17495 CEDFA-O23 New 23dBm 1550nm CATV EDFA Fiber Optic Amplifier
36458 CEDFA-BA Customized 1550nm CATV EDFA Fiber Optic Amplifierr

Originally published at http://www.china-cable-suppliers.com/using-edfa-amplifier-long-haul-catv-systems.html

CWDM and DWDM Network Solutions

Growing demands of the internet users is one of the reasons that lead using wavelength division multiplexing (WDM) networks to transmit optical data. So, what is WDM? WDM is a technology that multiplexes various optical signals through a single optical fiber by taking advantage of different wavelengths of laser light. And the ITU-T recommendation specifies the wavelengths used in CWDM/DWDM or OADM. All the passive fiber optic components are made of filters that only allow specific wavelength to pass through a fiber port and then the others to be reflected to another fiber ports.

WDM Network Overview

A WDM network uses a multiplexer at the transmitter to join the several signals together, and a demultiplexer at the receiver to split them apart. With the increasing demand of data, video and mobile usage on many networks, WDM technology has proved to be the most reliable and cost-effective in transporting large amount of data in telecom. And by utilizing CWDM and DWDM network systems to scale the bandwidth, the operators enable to transmit service from 2Mbps up to 100Gbps of data. Now WDMs are very popular in field of CATV, Internet, VoIP, audio and video solutions, and even bring FTTX solutions to the people’s daily life.

CWDM Network Solutions

CWDM stands for Course Wavelength Division Multiplexer. “Course” means the channel spacing is 20nm with a working channel pass band (±6.5nm or ±7.5nm) from the wavelengths center. CWDM MUX DEMUX Modules take advantage of conventional thin-film filter (TFFS) technology and that allow various channels within ITU G.694 Grid (1270nm~1610nm,1271nm~1611nm), to realize multiplexing or demultiplexing wavelengths over one fiber. Due to the use of cheaper CWDM uncooled laser or lower-quality multiplexer and demultiplexers without fiber amplifiers. The CWDM works at a 60 or 80 km transmission with the wavelength of 1550nm. So CWDM is a very attractive options in metro networks.

DWDM Network Solutions

DWDM stands for Dense Wavelength Division Multiplexer. The word “Dense” is referring to the very narrow channel spacing measured in Gigahertz (GHz) as opposed to nanometer (nm). DWDM us typically use channel spacing measured in GHz (100G or 200G, C-Band 1525nm~1565nm). Now an optical fiber inter-leaver or optic fiber chip is used to double the channel of 100GHz or 200GHz spacing, that’s 50GHz or 100GHz AWG. Just like CWDM MUX DEMUX, DWDM MUX DEMUX also takes the advantage of thin-film filters and are used to increase the amount of data capacity that can be transmitted over a single fiber. The DWDM will be with more channels with much tighter channel spacing. Typical DWDM MUX DEMUX modules only have 32, 40, 44 channels but today’s 50Ghz 100Ghz DWDM MUX DEMUX doubles the channel spacing and can reach up to 64, 80, 88 and even 90 channels.

40 channel Mux Demux

DWDM is the most suitable technology for long-haul transmission because of its ability to allow EDFA amplification. Given the growing need for bandwidth driven by data-hungry applications (smartphones, video streaming, etc.), DWDM has now found its way into metro networks, and is even being used in some cellular back-haul deployments.

Conclusion

WDM systems have become one of the major solutions to meet the growing demand for increased network bandwidth brought about by the rapid growth of Internet and data services. CWDM and DWDM network solutions have their own suitable applications. If you want to get more details for these solutions, kindly visit http://www.fs.com.

Necessary Components in DWDM Systems

DWDM (Dense Wavelength Division Multiplexing) is used to increase the amount of information or systems that can be transmitted over a single fiber, thus allowing allow for more channels with much tighter channel spacing. In DWDM systems, DWDM devices combine the output from several optical transmitters for transmission across a single optical fiber. At the receiving end, another DWDM device separates the combined optical signals and passes each channel to an optical receiver. This article covers DWDM system components that combine (multiplex) and separate (demultiplex) multiple optical signals of different wavelengths in a single fiber.

Optical Transmitters/Receivers

As the light sources in a DWDM system, the optical transmitters are of great importance to the whole system design. In DWDM systems, multiple transmitters are used to provide the source signals which are then multiplexed. Incoming electrical data bits (0 or 1) trigger the modulation of a light stream (e.g., a flash of light = 1, the absence of light = 0). Lasers create pulses of light, each with an exact wavelength. In an optical-carrier-based system, a stream of digital information is delivered to a physical layer device, whose output is a light source (an LED or a laser) that interfaces a fiber optic cable. Then the device converts the incoming electrical signals to optical form signals. Electrical ones and zeroes trigger a light source that flashes light into the core of an optical fiber. The format of the underlying digital signal is not changed. Pulses of light propagate across the optical fiber by total internal reflection. At the receiving end, another optical sensor (photodiode) detects light pulses and converts the incoming optical signals back to electrical signals. Two fibers are used in this process, one for transmitting and the other for receiving.

DWDM Mux/DeMux Modules

The DWDM Mux combines multiple wavelengths created by multiple transmitters and operating on different fibers. The output signal of an multiplexer is referred to as a composite signal. At the receiving end, the DeMux (demultiplexer) separates all of the individual wavelengths of the composite signal out to individual fibers. The individual fibers pass the demultiplexed wavelengths to as many optical receivers. Generally, Mux and DeMux components are contained in a single enclosure. Optical Mux/DeMux devices can be passive. Component signals are multiplexed and demultiplexed optically, not electronically, therefore no external power source is required.

DWDM MUX DEMUX Mux/Demux 40 Channels over Dual Fiber

Optical Add/Drop Multiplexers (OADM)

In a DWDM system, the optical add/drop multiplexers (OADM) can add or drop DWDM channels into an existing backbone ring. It provides the ability to drop one DWDM channel from the network fiber, while allowing all other channels to continue pass to other nodes. Similarly, the drop/insert module removes an individual channel from the network fiber, however, it also provides the ability to add that same channel back onto the network fiber.

Optical Fiber Amplifiers

Optical fiber amplifiers boost the amplitude or add gain to optical signals passing on a fiber by directly stimulating the photons of the signal with extra energy. Optical fiber amplifiers amplify optical signals across a broad range of wavelengths. They can provide flat gain over a large dynamic gain range, have a high saturated output power, low noise, and effective transient suppression. Erbium-doped fiber amplifier (EDFA) is the most widely used fiber amplifier which has received great attention over the past 10 years. EDFA is generally used for very long fiber links such as undersea cabling. It uses a fiber that has been treated or “doped” with erbium, and this is used as the amplification medium.

Transponders (OEO)

Transponders are also referred to as optical-electrical-optical (O-E-O) wavelength converters. They can convert optical signals from one incoming wavelength to another outgoing wavelength suitable for DWDM applications. A transponder performs an O-E-O operation to convert wavelengths of light. Within the DWDM system, a transponder converts the client optical signal back to an electrical signal (O-E) and then performs either 2R (reamplify, reshape) or 3R (reamplify, reshape and retime) functions.

DWDM System with Transponders

Conclusion

With all the necessary components, DWDM-based networks can transmit data in IP, ATM, SONET, SDH and Ethernet. Therefore, DWDM-based networks can carry different types of traffic at different speeds over an optical channel. If you want to learn more about all these components for DWDM system, kind visit http://www.fs.com for more details.

Passive DWDM vs. Active DWDM

To keep pace with the rapidly growing volumes of data-network traffic driven by the growth of the Internet, service providers are always looking to increase the fiber capacity and wavelength spectral efficiency in their networks. DWDW (dense wavelength division multiplexing) is an optical multiplexing technology used to increase bandwidth over existing fiber networks. DWDM works by combining and transmitting multiple signals simultaneously at different wavelengths on the same fiber. It has revolutionized the transmission of information over long distances. DWDM can be divided into passive DWDM and active DWDM which will be illustrated in this article.

Passive DWDM

“Passive” refers to the passive DWDM MUX/DEMUX element which is an unpowered, pure optical equipment. Passive DWDM systems have no active components, which means that no optical signal amplifiers and dispersion compensation modules (DCM) are used. The DWDM passive link is only determined by the optical budget of transceivers used. Passive DWDM system has a high channel capacity and potential for expansion, but the transmission distance is limited to the optical transceivers used. The main application of passive DWDM system is metro networks and high speed communication lines with a high channel capacity.

Active DWDM

Active DWDM system is built from transponders, providing full optical demarcation point agnostic to the routers, switches and ADMs within the network. Active DWDM offers a way to transport large amounts of data between sites in a data center interconnect setting. The transponder takes the outputs of the SAN or IP switch format, usually in a short wave 850nm or long wave 1310nm format, and converts them through an optical-electrical-optical (OEO) DWDM conversion. In long-haul DWDM networks, several EDFAs are installed sequentially in the line. The number of amplifiers in one section is determined by the fiber cable type, channel count, data transmission rate of each channel, and permissible OSNR value.

active DWDM

Besides, the maximum transmission distance of the active DWDM system also depends on the influence of chromatic dispersion—the distortion of transmitted signal impulses. When designing a DWDM network project, permissible values of chromatic dispersion for the transceivers should be considered, and, if necessary, chromatic dispersion compensation modules are included in the line. DCM fixes the form of optical signals that are deformed by chromatic dispersion and compensates for chromatic dispersion in fibers.

Choosing passive or active DWDM system depends on your requirements and current setup. Because both of them have pros and cons.

Passive DWDM
Pros:
1. Inexpensive – As mentioned above, less components are required, and less engineering time is required.

2. INITIAL Setup – Because of the colored optics there isn’t a need to tune wavelengths for all of your connections. It’s a matter of matching your colored optics and plugging it.

Cons:
1. Scalability – you are limited to colored optics, and less wavelengths on the transport fiber. As you grow, you would be required to have more passive devices. Furthermore, with the more passive devices, you have more difficulty to manage. And you will have to start managing the same wavelength on multiple passive devices and they could be serving different purposes on each depending on your setup.

2. Control – If you need to change a wavelength or connection for whatever reason, your option is limited to taking it out of service and disconnecting the physical cabling as the wavelength is tied to the optic.

Active DWDM
Pros:

1. Active can fit a lot more wavelengths (colors) onto a single fiber pair. The composite signal that is sent over a single fiber pair can carry more bandwidth than a passive of the same size, in turn you don’t need as much physical fiber between your two sites (this really only applies if you require that much bandwidth). This is advantageous when distance is a problem because it allows you to get more out of a single leased fiber pair as opposed to passive.

2. Active setups grant you more control over your optical network, you can dynamically re-tune wavelengths without dropping connections (it’s transparent to whatever is riding on that wavelength).

3. Scalability – Active can be easier to scale as your network grows (you can fit more wavelengths on the fiber, see above), but again – we’re talking seriously big iron. I’ll dig into it a bit more below.

Cons:
1. EXPENSIVE – Active DWDM setups are much more expensive compared to passive DWDM. If you don’t have long-distance requirements, don’t choose active DWDM.

2. Configuration – Depending on your vendor, configuration can be a serious undertaking, and require a solid understanding of optical networks. There are many more components in active builds.

Conclusion

Most of the time, DWDM operates with powered component like transponders. Further, after multiplexing the signals, they typically need active amplification to have any preferred reach. Without this, you’re only going with a relatively short distance, which is not a good value for the expense of DWDM.