Things to Consider When Choosing a WAP

FacebookLinkedInTwitterRedditGoogle+Share

Now since the intelligent mobile phone is more and more convenient, people have stronger and stronger demands for the Internet. As a result, the programs of wireless coverage have been increasing. At the same time, many people are confused about choosing a wireless access point (WAP). The post summarizes some tips for your reference when choosing a WAP.

Range

The distance covered is an important parameter in buying an AP. WAPs with range enhancements are advantageous as they reduce the number and general costs of access points. In general, adequate range lowers overall expenses to the client since fewer access points are required. Majority of enterprise wireless access points are able to give a coverage for an area between five thousand to ten thousand square feet. The range of a typical residential Wi-Fi network is dependent upon antenna sensitivity and one’s need.

Speed

This refers to the rate of information traveling, usually measured in bps (bits per second), kilobits, megabits or gigabits. In general, the speed of a wireless AP can reach 300Mbps or higher if the precise 802.11n protocol being supported, which is six times faster than 802.11n. While WAP supporting 802.11ac protocol can reach 1200Mbps.

Price

The price would depend on several factors. But one should keep in mind that not the higher the price is, the better an AP will be. High price would not only increase the cost, but also result in the waste of function and performance of product; on the contrary, low price would induce people to buy inferior-quality or fake products. So you should have a clear understanding of the actual performance of WAP in order not to be tempted by exaggerated advertising effect.

price

Features

Although there is a broad variety of features, they might not be what you need. You should select what you need most, and then do a bit of research into the device that you are going to buy. Be sure to take bps and range into consideration.

WAP Capacity

The capacity of a WAP is the number of users that it can support without a degradation of performance. Capacity is also an important factor when choosing a wireless AP. Although all manufactures will emphasize throughput in advertisements, few of them will reveal the specific number of users that their gadgets are capable of supporting.

Power over Ethernet (PoE)

Power over Ethernet has some evident advantages. For example, PoE support on wireless access points greatly simplifies the installation, reduces the cost, and saves data and power cables separately for each network device. It has high flexibility since the network device can be installed in any location without having to approach an existing power outlet. Last but not least, it has high reliability; a PoE device with SNMP capabilities can carry out remote detection and control, and can effectively handle or repair power consumption or malfunction of the device. Based on this, PoE is of great importance in choosing a WAP.

poe_raw

Gain Antenna

The antenna of wireless AP is basically built-in, unlike routers whose antenna is external. Therefore, the wireless AP antenna is very important, and it will directly affect the signal strength of wireless AP and the range of transmission. When you are purchasing a wireless AP, you’d better choose one with gain antenna.

Conclusion

Now there are a number of new devices which are more powerful and can support a wider area in the market for you to opt for, but be sure to find the right wireless access points based just on your needs and at the same time take a few factors into consideration such as range, speed, price, features, WAP Capacity, PoE, gain antenna, etc. And what’s more, it would be wise to checkout some of the feedback and reviews from a few products before you make your final decision.

Posted in Fiber Optic Network | Tagged , , | Comments Off on Things to Consider When Choosing a WAP

Guidance on Buying a Data Center Switch

Given the unprecedented development of network technology, switches have been widely used in some large-scale LANs and switch products are becoming increasingly rich. Thousands of enterprises like FS, Cisco, HP and Huawei provide varying level of switch products, such as Ethernet switch and fiber optic switch, to satisfy different demands. Customers may be dazzled and have no idea what to do with so many products. Therefore choosing the right switch for your data center can be a difficult task. This article introduces some basic information of data center switch and offers some references and suggestions on how to pick a good switch for you.

What Are Data Center Switches?

Network switches fall into four basic categories: core switches, distribution switches, access switches and data center switches, of which the first three fit into the classic three-tier enterprise network model while the last one is newer and currently used mainly by large enterprises and cloud providers that rely heavily on virtualization.

As for the type of optical switches, the most important feature of a fiber optic switch is that it adopts fiber optic cables as its transmission medium with the advantages of fast speed and strong anti-interference capability. Different types of switches have unique characteristics that, when used properly, better optimize the network as a whole. Over time, with developments in storage area networks (SANs) and the continued growth of virtualization , changes in data-center server architecture ushered in a new breed of high-performance switches—data center switches. The features of data center switch can be classified as follow:

  • Data center switches provide the physical port capacity and port throughput required to handle both north-south and east-west traffic flows.
  • Data center switches allow for connectivity using both standard LAN Ethernet protocol and SAN protocols, such as Fiber Channel over Ethernet and legacy Fiber Channel.
  • Data center switches have more extensive high availability and fault tolerance systems built into the hardware and software for better uptime for mission-critical applications.
  • Data center switches provide significantly higher deployment flexibility with both top-of-rack and end-of-row configuration compatibility.
  • Finally, all components of a distributed data center switch can be managed from a single management interface for ease of use.
How to Pick the Right Switch for You?

Before deciding what type of switch you should buy, you need to weigh a variety of factors, from routing requirements and port speeds to manufacturer support. Careful planning before making a switch purchase will save you money by ensuring you don’t wind up buying equipment that has functionality your organization doesn’t need. At the same time, it can exempt you from future worries by making sure you aren’t left with switches that can’t expand their capabilities as your requirements change and grow. Here are some points you can consider to help guide your switch purchase.

a) 100G Options
  • Range of switch form factors with 100G ports
  • Maximum number of 100G ports per rack unit
b) Sub-Microsecond Options
  • Range of switch form factors with sub-microsecond throughput
  • Maximum number of 100G ports per rack unit
c) Cloud, SDN and Virtualization Readiness
  • Support for OpenFlow (the higher the version, the better)
  • Certification of compliance with the highest version for which a testing suite is defined (typically several versions behind the current)
  • Vendor OF controller, and/or third-party and/or open source OF controllers certified with its hardware
  • OpenStack plugin
  • Physical switch support for VXLAN and/or NVGRE
d) Platform Unity, Manageability, Maintainability
  • Single operating system for all data center switches
  • Single management tool addressing whole DC switching portfolio and all features
  • Support for in-service software upgrades, so switches don’t have to be shut down  for upgrades

Once you have gone through these key points, you should be ready to do some switch shopping. Next I will introduce some top switches in the market for your reference.

Top Switches Product Overview
Type
Description
FS S5850-48S6Q data center switch

1. 48 SFP+ ports and 6 QSFP+ ports which provide 720Gbps non-blocking bandwidth and 1072Mpps L2/L3 throughput

2. Designed for traffic visibility and trouble shooting

3. Support VxLAN/NvGRE, including Routing

4. Support ECN and PFC, etc

5. Support up to 64 ways ECMP

6. Support Openflow image and NPB (TAP) image

7. Compatible with Cisco, Juniper, Arista switches, as well as other brands of switches

FS S5850-48S2Q4C data center switch
1. 48 SFP+ ports, 2 QSFP+ ports and 4 QSFP28 ports which provide 960Gbps non-blocking bandwidth and 1200Mpps L2/L3 throughput

2. Designed for traffic visibility and trouble shooting

3. Support VxLAN/NvGRE, including Routing

4. Support ECN and PFC, etc

5. Support up to 64 ways ECMP

6. Support Openflow image and NPB (TAP) image

7. Compatible with Cisco, Juniper, Arista switches, as well as other brands of switches

FS S5850-32S2Q data center switch

1. 32 SFP+ ports and 2 QSFP+ ports which provide 400Gbps non-blocking bandwidth and 596Mpps L2/L3 throughput

2. Designed for traffic visibility and trouble shooting

3. Support VxLAN/NvGRE, including Routing

4. Support ECN and PFC, etc

5. Support up to 64 ways ECMP

6. Support Openflow image and NPB (TAP) image

7. Compatible with Cisco, Juniper, Arista switches, as well as other brands of switches

Conclusion

A good data center switch can provide enterprise organizations with significant advantages in performance, availability and ease of management. I hope this article can help you find a suitable data center switch for your organization.

Posted in 40/100G Ethernet, How to | Tagged , | Comments Off on Guidance on Buying a Data Center Switch

Migrating to 40/100G Networks With MTP Harness Conversion Cable

The market turning to 40G/100G transmission is imperative in today’s gigabit Ethernet applications. MTP cabling assemblies, with their overwhelming advantages, provide a fast, simple and economical upgrade path from 10 Gigabit to 40 or 100 Gigabit applications. As we all know, 40G/100G gigabit Ethernet backbone networks often use 8-fibers per channel, which means most existing equipment doesn’t utilize fibers fully in 12-fiber cabling systems. Today this post will introduce a type of MTP fiber cable—MTP conversion cable which can overcome the problem mentioned above.

Basis of 40G/100G MTP Conversion Cable

12-fiber MTP connectors are popular in the past years. And most backbone networks deploy the 12-fiber cabling systems. But with the quick development of optical transceivers, for 40G/100G gigabit applications, many transceivers that are guiding the industry from 10G to 40G and100G utilize only eight fibers. Then the problem arises. However, MTP conversion cable allows users to convert their existing MTP backbone cables to an MTP type which matches their active equipment. It’s a low-loss alternative to conversion modules because they eliminate one mated MTP pair across the link. There are mainly three types of MTP conversion cable on the market: 1×2, 1×3 and 2×3 MTP conversion cable.

1×2 Harness MTP Conversion Cable

This MTP conversion cable has a 24-fiber MTP connector on one end and two 12-fiber MTP connectors on the other end. It is used to allow existing 10G MTP 12-fiber trunk cables to carry 40G/100G channels. The 40G/100G signal is split equally across two 12-fiber trunks which were previously installed within a traditional MTP modular network.

1x2 MTP conversion cable

1×3 MTP Harness Conversion Cable

Like the 1×2 MTP conversion cable, this conversion cable also has a 24-fiber MTP connector on one end. But the other end comprises three 8-fiber MTP connectors, which is different from the former type. This MTP conversion cable allows users to convert their 24-fiber backbone trunks into Base-8 connections so that 40G rates can be achieved easily. A Single Base-24 connection is split out to three Base-8 connections, giving users three 40G ports.

1x3 MTP conversion cable

2×3 Harness MTP Conversion Cable

For users who have already installed a 10G MTP based network using 12-fiber and 24-fiber trunk cables and modules, this 2×3 MTP conversion cable can provide the conversion from 12-fiber to 8-fiber connectivity for full-fiber utilization, especially allowing for maximum use of existing fibers when converting to 40G channels. Because the conversion cable has two 12-fiber MTP connectors on one end and three 8-fiber MTP connectors on another end. They are available in either direct or crossed polarity for fast deployment using polarity management method A, and polarity can be reversed on site, offering enhanced flexibility & operability.

2x3 MTP conversion cable

Cabling Options with 40G/100G MTP Conversion Cable

The 40G/100G MTP conversion cables eliminate the wasted fibers in current 40 gigabit transmissions and upcoming 100 gigabit transmission. Compared to purchase and install separate conversion cassettes, using MTP conversion cables is a more cost-effective, lower-loss option. Here are three application examples.

Cabling Options for 40G/100G Connectivity With 1×3 MTP Conversion Cable

As shown in the picture below, two 40G/100G switches are connected by 1X3 MTP conversion cables (one 24-fiber MTP connector on one end and three 8-fiber MTP connectors on the other end), 24-fiber MTP trunk cable and MTP adapter panels. With this MTP conversion cable, less fiber cables are required. That brings more conveniences for cable management in data centers.

1x3 MTP conversion cable soulution

The cabling solution for 40G/100G conversion with 1×2 MTP conversion cable is similar to the solution of 1×3 MTP conversion cable.

Cabling Options for 40G Connectivity With 2×3 MTP Conversion Cable

In the following applications, connecting the 40G transceivers with a 8-fiber MTP conversion cable rather than a traditional 12-fiber MTP jumper, can enscure the 100% backbone fiber utilization and saving cost.

2x3 MTP conversion cable soulution

Summary

The 40G/100G MTP conversion cables provide a cost-effective cabling solution for upgrading to 40G and 100G networks. All the benefits and features of these MTP conversion harness cables are explained in the article. And the three types of 40G/100G MTP conversion cable which are available in OS2, OM3 and OM4 options are provided in FS.COM. If you want to know more details, please contact us via sales@fs.com.

Posted in MPO MTP | Tagged , , | Comments Off on Migrating to 40/100G Networks With MTP Harness Conversion Cable

Comparison of OM1, OM2, OM3 & OM4

Multimode and single-mode optical fiber cables are two different cable types in optical networking. Using a larger core size, multimode fiber cable allows multiple light signals to be transmitted in a single fiber over short distances. Multimode fiber systems offer flexible, reliable and cost effective cabling solutions for local area networks (LANs), storage area networks (SANs), central offices and data centers. Unlike the complex classifications of single-mode fiber, multimode fiber is usually divided into four types of OM1, OM2, OM3, OM4. “OM” is abbreviated for optical multimode, and it is specified by the ISO/IEC 11801 international standard. Of course, these four types of multimode fiber have different specifications (as shown in the following table). The article will compare these four kinds of fibers from the side of core size, bandwidth, data rate, distance, color and optical source in details.

specification of OM1, OM2, OM3 and OM4

Core Size

Multimode fiber is provided with the core diameter from 50 µm to 100 µm. Apart from OM1 with a core size of 62.5 µm, other three types are all using the 50 µm. The thick core size makes them able to carry different light waves along numerous paths without modal dispersion limitation. Nevertheless, in the long cable distance, multiple paths of light can cause signal distortion at the receiving end, resulting in an unclear and incomplete data transmission. And this is why all the types of multimode fiber can only be used for short distance.

Bandwidth

Bandwidth is the bit-rate of available or consumed information capacity expressed typically in metric multiples of bits per second. The higher bandwidth is, the faster transmission speed can be. According to overfilled launch (OFL) and effective modal bandwidth (EMB) measurements, OM1 and OM2 can only support OFL, but OM3 and OM4 are able to support both measurements. At the wavelengths of 850/1300 nm under OFL, the respective bandwidth of OM1, OM2, OM3, OM4 is 200/500 MHz*km, 500/500 MHz*km, 1500/500 MHz*km and 3500/500 MHz*km. And at the wavelength of 850 nm under EMB, the bandwidth of OM3 is 2000 MHz*km and OM4 even reaches 4700 MHz*km.

Data Rate

Data rate is a technical term that describes how quickly information can be exchanged between electronic devices. With a higher data rate, the transmission can be more effective. OM1 and OM2 support the Ethernet standards from 100BASE to 10GBASE with a minimum data rate of 100 Mbps and a maximum data rate of 10 Gbps. Compare with OM1 and OM2, OM3 and OM4 are enhanced to support much higher data rates of 40 Gbps and 100Gbps in 40G and 100G Ethernet.

Distance

Multimode fiber is typically used for short distance transmission. But the maximum reaches are varied in different multimode fiber types. Also, on account of different data rates, the transmitting distances are different. However, the common feature is that OM1 always supports the shortest distance yet OM4 supports the longest. For instance, based on the same data rate of 10 Gbps, the maximum reach of OM1 is 33 m, OM2 is 82 m, OM3 is 300 m and OM4 is 550 m. Thus, if a medium-sized transmission is required, OM3 and OM4 are the best choices.

Color & Optical Source

The outer jacket can also be a method to distinguish OM1, OM2 from OM3, OM4. The common jacket color of OM1 and OM2 is orange, and OM3, OM4 are in aqua. In addition, OM1 and OM2 are using a light-emitting diodes (LEDs) optical source but OM3 and OM4 adopt the vertical-cavity surface-emitting laser (VCSELs) optical source.

color and optical source of OM1, OM2, OM3 and OM4

Application

OM1 and OM2 are widely employed for short-haul networks, local area networks (LANs) and private networks. OM3 is applied to a larger private networks. Different from the previous multimode types, OM4 is more advanced to be used for high-speed networks in data centers, financial centers and corporate campuses.

Conclusion

It is very important to choose the right fiber type for your application. Future-proofing network design is crucial for network planning, but there is often a cost for that speed. With a higher performance, OM3 and OM4 are definitely more expensive than OM1 and OM2. So plan well and spend wisely.

Posted in Fiber Optic Cable | Tagged , , , , | Comments Off on Comparison of OM1, OM2, OM3 & OM4

Multimode Fiber Optic Patch Cable Overview

We know that fiber optic patch cables play a very important role in the connection between devices and equipment. When talking about fiber optic patch cables, we usually divide them into multimode fiber optic patch cables and singlemode fiber optic patch cables according to the modes of the cable. What is multimode fiber optic patch cable? How many types of multimode patch cables are there? And what is the difference between multimode and singlemode patch cables? What are the applications of multimode patch cables? This text will solve those questions one by one.

Introduction

Multi-mode fiber patch cables are described by the diameters of their core and cladding. There are two different core sizes of multi-mode fiber patch cords: 50 microns and 62.5 microns. Both 62.5 microns and 50 microns patch cable feature the same glass cladding diameter of 125 microns. Thus, a 62.5/125µm multi-mode fiber patch cable has a 62.5µm core and a 125µm diameter cladding; and a 50/125µm multi-mode fiber patch cable has a 50µm core and a 125µm diameter cladding. The larger core of multi-mode fiber patch cords gathers more light and allows more signals to be transmitted, as shown below. Transmission of many modes of light down a multi-mode fiber patch cable simultaneously causes signals to weaken over time and therefore travel short distance.

singlemode fiber vs multimode fiber

Types of Multimode Fiber Optic Patch Cable

Multimode fiber optic cables can be divided into OM1, OM2, OM3, and OM4 based on the types of multimode fiber. The letters “OM” stands for optical multimode. OM1 and OM2 belong to traditional multimode fiber patch cable, while OM3 and OM4 belong to the new generation fiber patch cable which provides sufficient bandwidth to support 10 Gigabit Ethernet up to 300 meters. The connector types include LC, FC, SC, ST, MU, E2000, MPO and so on. Different type of connector is available to different equipment and fiber optic cable.

By the materials of optic fiber cable jackets, multimode fiber patch cord can be divided into four different types, PVC, LSZH, plenum, and armored multimode patch cable. PVC is non-flame retardant, while the LSZH is flame retardant and low smoke zero halogen. Plenum is compartment or chamber to which one or more air ducts are connected and forms part of the air distribution system. Because plenum cables are routed through air circulation spaces, which contain very few fire barriers, they need to be coated in flame-retardant, low smoke materials. Armored fiber patch cable use rugged shell with aluminum armor and kevlar inside the jacket, and it is 10 times stronger than regular fiber patch cable.

Difference Between Singlemode and Multimode Patch Cables

Multimode and singlemode fiber optic patch cables are different mainly because they have different sizes of cores, which carry light to transmit data. Singlemode fiber optic patch cables have a core of 8 to 10 microns. Multimode fiber patch cable allows multiple beams of light passing through, while singlemode fiber cable allows a single beam of light passing through. As modal dispersion happens in multimode fiber cable, the transmission distance is relevantly nearer than singlemode fiber cables. Therefore, multimode fiber optic patch cable is generally used in relevantly recent regions network connections, while the singlemode fiber cable is often used in broader regions.

Applications of Multimode Fiber Optic Patch Cable

Multi-mode fiber patch cables are used to connect high speed and legacy networks like Gigabit Ethernet, Fast Ethernet and Ethernet. OM1 and OM2 cables are commonly used in premises applications supporting Ethernet rates of 10Mbps to 1Gbps, which are not suitable though for today’s higher-speed networks. OM3 and OM4 are best multimode options of today. For prevailing 10Gbps transmission speeds, OM3 is generally suitable for distance up to 300 meters, and OM4 is suitable for distance up to 550 meters.

Conclusion

Fiber optic patch cords are designed to interconnect or cross connect fiber networks within structured cabling systems. Typical fiber connector interfaces are SC, ST, and LC in either multimode or singlemode applications. Whether to choose a singlemode or multimode fiber patch cable, it all depends on applications that you need, transmission distance to be covered as well as the overall budget allowed.

Posted in Fiber Optic Network | Tagged , , , , , | Comments Off on Multimode Fiber Optic Patch Cable Overview

Select Best Ethernet Cable (Cat5/5e/6/6a) for Your Network

There is no doubt that wire connections that based on Ethernet cables usually have faster speed yet lower latency than Wi-Fi connections. And owing to the advanced technology, modern Ethernet cable can communicate at even faster speeds. When to install a network for your home, office or business, you may come across these questions: With various types of network cables available, what do I really need? Is it a Cat5, 5e, 6 or 6a, shielded or unshielded, UTP or STP? Thus, we are supposed to answer these frequently asked questions in the article.

Ethernet Cables Overview

Based on different specifications, Ethernet cables are standardized into sequentially numbered categories (“cat”) like Cat4, Cat5, Cat6 and etc. Each cable with a higher number is a newer standard, and these cables are backwards compatible. Sometimes the category can be further divided by clarification or testing standards, such as Cat5e and Cat6a. According to these different categories, it is easier for us to know what type of cable we need for a specific application.

Cat5e, Cat6, Cat6a cables

Cat5 (Category 5) cable serves as an older type of Ethernet network cable. It is designed to support theoretical speeds of 10 Mbps and 100 Mbps. Cat5 cable is capable of operating at gigabit speeds as well, especially when the cable is shorter, however, this cannot be guaranteed. Currently, Cat5 cable is rarely seen in the store, but there are still some with an older router, switch, or other networking device.

Cat5e (Category 5 enhanced cabling) cable is known as an improved version of Cat5 cabling. And with the enhanced signal carrying capacity, it is faster than Cat5 cable. Cat5e was made to support Ethernet, Fast Ethernet, and Gigabit Ethernet speeds over short distances and is backward compatible with Cat5. Meanwhile, it decreases the chance of crosstalk, the interference you sometimes inevitable to get between wires inside the cable. Cat5e cable also features improved durability because of improvements in the quality of the PVC protective jacket. It is more than suitable for most data cabling requirements.

Cat6 (Category 6) cable is the next step up from Cat5e. and it was specifically designed to consistently deliver 1 Gigabit Ethernet. When it comes to interference, Cat6 cable has even stricter specifications. Since the improvement in interference makes no big difference in regular usage, there is no need to rush out to Cat6 upgrade. However, when you propose to buy a new cable, you could try Cat6 because it is an improvement over the former types.

Cat6a (Cat6 augmented) is designed to 10 Gigabit speeds and is backward compatible with all the existing standards. Besides, it can be used in industries utilizing high-performance computing platforms to support very high bandwidth-intensive applications. Server farms, storage area networks, data centers and riser backbones are common 10G/Cat6a applications.

Categories of Ethernet Cables Signal Carrying Capacity Typical Uses
Cat5 Ethernet and Fast Ethernet Home, Home Office, Small Office
Cat5e (enhanced) Ethernet, Fast Ethernet, and Gigabit Ethernet (short distance) Home, Small Office, Gaming Consoles, Computer Networks
Cat6 Ethernet, Fast Ethernet, and 1 Gigabit Ethernet (consistent) Large Networks, Data Centers, Offices, Cat6 Certified Networks
Cat6a (Augmented) Ethernet, Fast Ethernet, and 10 Gigabit Ethernet Large Data Centers, Large Offices, Server Farms, Future Proofing New Equipment
Factors to Consider When Choosing Ethernet Cables

Through the revolution of Ethernet cables, we know that each newer standard brings higher possible speeds and reduced crosstalk. But how those categories distinct from each other? When to use unshielded, shielded, stranded, or solid cable? The following three factors are necessary to consider.

Unshielded (UTP) vs. Shielded (STP)

All Ethernet cables are twisted thus the shielding is used to further protect the cable from interference. Network cable typically comes in two basic types: STP (Shielded Twisted Pair) and UTP (Unshielded Twisted Pair).

UTP: UTP cable is comprised of four pairs of carefully twisted pairs of copper wire, insulated with carefully chosen material to provide high bandwidth, low attenuation and crosstalk. UTP can easily be used for cables between your computer and the wall, and it is also the most common type of cabling used in desktop communications applications.

STP: As for STP cable, cable pairs (not individual wires) are shielded by a metallic substance, and then all four pairs are wrapped in yet another metallic protector. This is done in the purpose of preventing interference via the usage of three techniques known as shielding, cancellation and wire twisting. The problem is that STP is harder to install. You will use STP for areas with high interference and running cables outdoors or inside walls.

UTP vs STP cablesPVC Jacket vs. Plenum Rated

PVC: The most common kind of network cable is PVC. PVC is usually used as the covering for patch cables, and often for bulk cables. The problem is that PVC covered will releases toxic smoke when burning. In this case, most local fire codes prohibit PVC covered cable from being used in air handling spaces. But it is accepted to use PVC cable in wall installations. To be on the safe side, you should check your local fire codes.

Plenum: Plenum rated cable has a covering that burns without toxic smoke. In construction, plenum refers to the separate space provided for air circulation, heating, and venting. In a standard commercial building, the plenum is the space between the drop ceiling and the structural ceiling. While in residential installations, the plenum could be in a few places such as the floor when floor level air circulation is used.

PVC vs. Plenum

Stranded vs Solid Core

By solid and stranded Ethernet cables, it means the actual copper conductor in the pairs. The differences lie in that solid cable uses a single piece of copper for the electrical conductor, while stranded uses a series of copper cables twisted together. There are two main applications for each type you should know about.

Stranded vs. Solid Core

Stranded cable is more flexible and should be used at your desk, or anywhere you may move the cable around often. It is much better for patch cables where flexibility is very important.

Solid cable is not as flexible but it is also more durable, which makes it ideal for permanent installations as well as in walls and ceilings. Termination will be easier and more reliable with solid core cable. Besides, it has very good attenuation properties thus easier to send a signal over. As such, solid core is best for long runs.

Conclusion

As the core and backbone of any network, network cables matter to overall communication and efficiency. Cat5e can be used for most home and office applications, and Cat6 and Cat6a to establish a large network such as high speed servers and data centers. However, your final decision should be based on your need and network demand, and remember to take the above factors into consideration.

Posted in Copper Network | Tagged , , , , , | Comments Off on Select Best Ethernet Cable (Cat5/5e/6/6a) for Your Network

How to Build a Passive DWDM Network?

DWDM technology has been regarded as an ideal solution for long haul optical transmissions. Usually the common passive system is CWDM but not DWDM. However, passive DWDM network also can offer perfect performance in some cases. This post focuses on the process of building a passive DWDM network, which includes the selection of related products, loss calculation and other factors needed to consider.

Passive DWDM Network Basis

In general, “passive” in DWDM optical networks means there are no powered parts inside, which is opposed to an active system that has a powered element like EDFA (erbium doped amplifier). In a passive DWDM network, the line functions only due to the use of optical transceiver. Passive DWDM systems have a high channel capacity and potential for expansion. The drawback is that passive DWDM networks only suit long runs applications.

passive DWDM

Passive systems have the same wavelength channel capacity as active systems. Though passive DWDM network has a limited transmission distance, it is more cost-saving and simpler compared with active DWDM systems. Because it doesn’t need active components like optical amplifiers or OEO transponder. And passive DWDM network is easy to control due to its physical cabling that the wavelength is tied to the optic.

How to Build a Passive DWDM Network?

Building a passive WDM network, no matter passive CWDM or DWDM network, is not an easy task. There are many factors that need to be taken into consideration. Now in the following part, I will give an example of a client to illustrate how to build a passive DWDM network.

Targeted Passive DWDM Network Overview & Design

Situation: there are four optical rings DWDM links using single mode fiber cable. The distance of each ring is 10km. And each ring has up to 21 outdoor cabinets.

Requirements: all equipment should be passive (no power/cooling required); all outdoor cabinets will serve business customers with direct fiber cable. (PON splitters 1:8 at least); the ring should be designed with redundancy standards. And the goal is to serve our customers with high quality protected data services via fiber optic cables.

Here is a simple graph showing the passive DWDM network structure (cabinets have been omitted in this graph).

DWDM network

Selection of products. According to the requirement of the customer, these products are needed in the connection.

Product Description
DWDM MUX/ DEMUX 32 Channels Single Fiber DWDM MUX/ DEMUX
DWDM OADM Single Fiber DWDM OADM, Splice Pigtailed ABS Module
DWDM SFP 1000BASE-DWDM SFP 100GHz 120km DOM Transceiver
Fiber optic patch cord 10m Duplex Fiber Optic Patch Cord

Loss calculation. Each connector introduces loss in optical connections. Considering the changes of some components, the loss calculation is a little different from the one I mentioned in the article How to Calculate DWDM System Loss in Long Haul Transmission, which just shows the calculation of part connections in a link. In this connection, the total loss=fiber optic mux loss+ fiber loss+connectors loss+ OADM loss. According to the components used, the total loss is 32dB.

Deployment. After determining the products and power budget of the whole links, the next step is to deploy all components in the links. And learning some tips like avoiding end face contamination, or not bending fiber cables, will be helpful.

Summary

This post just gives a simple illustration to build a passive DWDM network. In fact, in actual DWDM network, there are various factors to consider. For instance, transmission distance, data rate, power budget, selection of optical components, etc. And even in final deployment, other problems may also arise. Therefore, quality products and professional team are important when designing passive DWDM networks. FS.COM, as a professional optical components and solutions supplier, can provide you reliable support for your DWDM networks. Welcome to visit FS.COM for more detailed information.

Posted in CWDM & DWDM Solutions, How to | Tagged , | Comments Off on How to Build a Passive DWDM Network?

Effectively Manage Power Cord in Your Rack

Power cords are extensively adopted in data centers and server rooms to deliver power to various electronic loads and computer equipment. Judging solely from their appearance, you may find that there exist a confusing array of power cords with various plugs and receptacles. Not to mention that the application of each also varies largely. So how to identify power cords and get them organized within your IT rack? This article may solve your problem.

What to Know About Power Cord?

The connection of electronic equipment to the AC power supply is achieved by power cord, which has detachable connectors on both ends. There are three parts involved in a power cord: a cable plug (male connector) that can be inserted into AC outlet to provide power, a receptacle (female connector) to be attached to equipment, and a cord that connects these two parts. In this section, power cords with various connector types are presented, with a detailed analysis of their names, appearance and applications.

power cord

IEC 60320 Power Cord

The International Electrotechnical Commission (IEC) has published international standards IEC 60320 for power cords. You can find IEC 60320 C13 to C14 connector on almost all personal computers and monitors. It has a rating of 10 amps and the female connector end is noted as C13 while the male connector end is noted as C14. The IEC 60320 C19 to C20 connectors are rated for 16 amps and again have a female connector end (C19) and a male connector end (C20). C19 to C20 connectors are commonly used for devices such as some servers and UPS systems. The details of IEC C13 to C14 power cord and C19 to C20 power cord are presented below.

IEC 60320 C13-C14 & C19-C20

NEMA Power Cord

Established by the National Electrical Manufacturers Association (N.E.M.A.), NEMA describes various connectors used on power cords throughout North America and some other countries. NEMA devices range in amperages from 15-60, and in voltages from 125-600. The most common NEMA connectors are the 5-15 and 5-20 designations. The first number indicates the plug configuration. This includes the number of poles and wires and the voltage. The second number in the code indicates the amp rating of the device, and is followed by an “R” for receptacle, or a “P” for a plug. For example: 5-15R is a 125V, 2-pole, 3-wire receptacle rated at 15 amps and is the most commonly found power outlet in houses in the U.S.

NEMA 5-15p to 5-15r

Amps vs Wire Gauge

There is a direct correlation between cable length, amperage and wire gauges. The following list is a basic breakdown of the relationship of amperage vs wire gauge. These are only basic guidelines, so as the length of the cord is increased either the amps will decrease or the wire gauge will have to be increased.

Amperage Recommended Wire Gauge
7a 20 AWG
10a 18 AWG
13a 16 AWG
15a 14 AWG
20a 12 AWG
Wire Color-Coding

For safety and convenience reasons, wire color-coding standards were developed for the jackets of the individual conductors inside power cords. Below is a list of the US and European color-coding standards. Please note that these apply to most power cords in the US and Europe. Color-coding may vary in certain applications.

Wire USA Color EU Wire Color
Live Wire Black Brown
Negative Wire White Blue
Ground Wire Green Yellow/Green

Safety Issues: connectors of power cords are made differently for various utilization voltages, with the purpose of preventing equipment designed for one voltage to be inadvertently connected to another. Using power cords with either higher or lower voltage than the equipment designed voltage is harmful-it may damage the equipment or present a fire hazard.

Tips for Manage Power Cords Within Racks

Power cords and data cords, such as fiber optic cables or copper cables, are inevitably co-exist within an IT rack. It is necessary to get them organized for better network performance and aesthetic appeals. We offer three tips here to achieve efficient power cord management.

Tip One: Separate power and data cables

We know the fact that EMI can deteriorate the performance of cables. Separating power and fiber optic cables contributes to minimize the effects of EMI, prevent erratic or error-prone data transfer and reduce human error. It you must cross power and data cables in some specific environments, try to cross them perpendicular to each other to minimize EMI. It is suggested to bundle data cables on one rear side of the IT rack and distribute power cables at the other rear side of the IT rack. Use high quality fiber optic cables is also beneficial to minimize EMI.

separate power cord and data cord

Tip Two: Use colored power cords

Good identification and administration of power cord are essential. Using colored power cords is a good practice to simplify the management of equipment inside the rack. Colored power cord allows for easy identification of power paths, simplified manageability of main and redundant power sources and efficient installation, giving your server room a clean and organized appearance.

colored power cord

Tip Three: Label power cords

Labeling both ends of the power cord is an integral part of the infrastructure installation and testing process, and is simply a good investment. It will save you much time and energy when finding the target power cord, and distinguishing one from another.

Conclusion

Power cord serves as an integrate part to provide the necessary power supply to your network. In this article, we have guide you through the basic knowledge associated with power cords, as well as some tips for efficient power cord management in IT racks. Hope it could help you to identify and choose the ideal power cord.

Posted in Fiber Optic Network | Tagged , , | Comments Off on Effectively Manage Power Cord in Your Rack

How to Place EDFA for DWDM Distance Extension?

Erbium doped fiber amplifier (EDFA) is the latest state-of-the-art solution for amplifying optical signals in optical transmission systems. It has become a key enabling technology and the dominant amplification device deployed in optical networks. Together with DWDM technology, EDFA has made it possible to transmit data over long distance. Broadly speaking, optical amplifiers may be used within an optical network as boosters, in-line amplifiers and pre-amplifiers. This article guides you to optimize your DWDM network reach by setting EDFA amplifiers in proper position.

What Is EDFA and How Does it Work?

EDFA works to directly amplify any input optical signal, eliminating the need to convert the signal into the electrical domain, thus offering the potential to reduce bandwidth transport costs. Since fiber attenuation limits the reach of a non-amplified fiber span to approximately 200 km, wide area purely optical networks cannot exist without an optical amplifier. Currently, EDFA has gained in more popularity because of features such as polarization independent gain, low noise, low cost and very low coupling losses.

edfa basic configuration

The basic form of EDFA consists of a length of EDF, a pump laser, and a WDM system for combining the signal and pump wavelength so that they can propagate simultaneously through the EDF. The most common configuration of EDFA is the forward pumping configuration using 980nm pump energy. Which offers the best overall design with respect to performance and cost trade-offs.

Different Positions and Functions of EDFA in DWDM Links

Within a DWDM system, EDFA can be placed in three different places for power compensation: used as booster optical amplifiers on the transmitter side to provide high input power to the fiber span, as in-line amplifiers to compensate for fiber loss in the transmission, and as preamplifiers at the receiver end to boost signals to the necessary receiver levels.

edfa in DWDM network

A booster optical amplifier operates at the transmission side of the link, working to amplify aggregated optical input power for reach extension. Booster EDFA is designed to enhance the transmitted power level or to compensate for the losses of optical elements between the laser and optical fibers. It is usually adopted in a DWDM network where the multiplexer attenuates the signal channels. Booster optical amplifier features high input power, high output power, and medium optical gain.

booster optical amplifier

An in-line amplifier is generally set at intermediate points along the transmission link in a DWDM link to overcome fiber transmission and other distribution losses. Optical line amplifier is designed for optical amplification between two network nodes on the main optical link. In-line amplifiers are placed every 80-100 km to ensure that the optical signal level remains above the noise floor. It features medium to low input power, high output power, high optical gain, and a low noise figure.

optical line amplifier

A pre-amplifier operates at the receiving end of a DWDM link. Pre-amplifiers are used for optical amplification to compensate for losses in a demultiplexer located near the optical receiver. Placed before the receiver end of the DWDM link, pre-amplifier works to enhance the signal level before the photo detection takes place in an ultra-long haul system, hence improving the receive sensitivity. It features medium to low input power, medium output power, and medium gain.

pre-amplifier

How to Set up EDFA for DWDM Network Extension?

By placing booster optical amplifier, optical line amplifier and pre-amplifier in different position of a DWDM link, the possible network reach extension can be achieved.

Booster for 10 Gbps point-to-point connections up to 170 km

Distances of optical transmission systems can be extended by using EDFA. Three different EDFA types can be used depending on the required distance and existing locations. Simply by putting a booster optical amplifier at the beginning of a DWDM link, up to 170 km can be accomplished in a point-to-point connection.

Booster for 10 Gbps up to 170 km

Pre-amplifier ensures up to 250km reach without any in-line amplifier

As the booster amplifier set at the beginning extends the link reach to 170 km, with the additional use of a pre-amplifier at the end of a transmission, the achievable distance of the entire system can be increased up to 250 km.

Pre-amplifier ensures up to 250km reach

Single in-line amplifier for 400km transmission even With100 Gbps

Installing an EDFA at one repeater site, a distance of up to 400 km can be realized. And this can be further extended if more repeater sites are used to place optical line amplifier. All three types of amplifiers are already designed to support 100 Gbps bandwidth for realizing up to 1000 km in a point-to-point connection. For this purpose multiple repeater sites and a Forward-Error-Correction (FEC) integrated in the used optics are required.

Single in-line amplifier for 400km with100 Gbps

Conclusion

Appropriate deployment of EDFA as booster, in-line amplifier and pre-amplifier in a DWDM link contributes to optimize network performance for extending the reach. Which also increases data capacity required for current and future optical communication system. Hope the discussion in this article is informative enough to get a better understanding of EDFA optical amplifier.

Posted in CWDM & DWDM Solutions, How to, Optical Fiber Amplifiers | Tagged , , , , | Comments Off on How to Place EDFA for DWDM Distance Extension?

DWDM Topology Design: How to Make it Right?

Network expansion spurs the demand for faster data transmission and higher capacity over the network. In this case, DWDM emerges as a cost-effective solution to handle these issues, working efficiently to combine multiple wavelengths together and sent them over one single fiber. With the ability to carry up to 140 channels theoretically, higher capacity can be achieved by DWDM technology. This article guides you through some basics of DWDM topology.

Common DWDM Topology Overview

DWDM networks are grouped into four major topological configurations: DWDM point-to-point with or without add-drop multiplexing network, fully connected mesh network, star network, and DWDM ring network with OADM nodes and a hub. The requirements of each DWDM topology differ, and based on various application, it may involve different optical components. Besides these four common DWDM topology, there also exists hybrid network topology, consisting of stars and/or rings that are interconnected with point-to-point links.

Configurations of DWDM Topology

This section illustrates the four basic DWDM topology configurations, help to understand the major differences and applications of them.

Point-To-Point Topology

Point-to-point topology is typically found in long-haul transport, which demands for ultra high speed (10-40Gb/s), ultra high aggregate bandwidth, high signal integrity, great reliability, and fast path restoration capability. The transmitter and receiver within this DWDM topology can be several hundred kilometers away, and the number of amplifiers between the two end points is generally less than 10. Together with add-drop multiplexing, point-to-point DWDM topology enables the system to drop and add channels along its path. A DWDM point-to-point system includes lasers, an optical multiplexer and demultiplexer, fibers, optical amplifiers, and an optical add-drop multiplexer.

point-to-point dwdm topology

Ring-Configuration Mesh and Star Networks

Basically, a DWDM ring network includes a fiber in a ring configuration that fully interconnects nodes. Two fiber rings are even presented in some systems for network protection. This ring DWDM topology is commonly adopted in a local or a metropolitan area which can span a few tens of kilometers. Many wavelength channels and nodes may be involved in DWDM ring system. One of the nodes in the ring is a hub station where all wavelengths are sourced, terminated, and managed, connectivity with other networks takes place at this hub station. Each node and the hub have optical add-drop multiplexers (OADM) to drop off and add one or more designated wavelength channels. As the number of OADMs increases, signal loss occurs and optical amplifier is needed here.

dwdm ring network

In the ring DWDM topology, a hub station works to manage channel assignment so that a fully connected network of nodes with OADM is accomplished. The hub also makes it possible to connect other networks. A DWDM mux/demux can be connected to an OADM node to multiplex several data sources. The following picture demonstrates a simple DWDM ring topology with a hub and two nodes (A and B).

dwdm ring topology with hub

Transmit and Receive Directions of DWDM Hub

In the previous part, we’ve mentioned DWDM hub, which serves as a very essential parts in a DWDM system. Here we further explain the transmit and receive direction of a DWDM hub, proving system solutions for your reference.

Transmit Direction

A DWDM hub accepts various electrical payloads, such as communications transport protoco/Internet Protocol (TCP/IP), asynchronous transfer mode (ATM), STM, and high-speed Ethernet (l Gb/s, 10 Gb/s). Each traffic type (channel) is sent to its corresponding physical interface, where a wavelength is assigned and is modulated at the electrical-to-optical converter. The optically modulated signals from each source are then optically multiplexed and launched into the fiber.

dwdm hub in the transmit direction

Receive Direction

When a hub receives a WDM signal, it optically demultiplexes it to its component wavelengths (channels) and converts each optically modulated signal to a digital electrical signal. Each digital signal then is routed to its corresponding electrical interface: TCPIIP, ATM, STM, and so on However, that each channel requires its own clock recovery circuitry because all channels may be at different bit rates.

dwdm hub in the receive direction

Conclusion

The network topology of your DWDM system depends on various factors, including the number of nodes, maximum traffic capacity, scalability, number of fiber links between nodes and so on. Attentions also should be attached to the network components involved in the DWDM system. Hope this article could help to get more understanding towards DWDM technology.

Posted in CWDM & DWDM Solutions, DWDM, Fiber Optic Network | Tagged , , , | Comments Off on DWDM Topology Design: How to Make it Right?