博文

目前显示的是 七月, 2016的博文

SFP+ DAC Cables for Cisco Catalyst 4500-X Series Switch

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Driven by the cloud computing and improvement of technology, 21st century witnesses a major shift from traditional enterprise data centers to much larger cloud data centers. These large data centers require a much higher-performance network, and need to interconnect many thousands of servers with predictable bandwidth and low-latency. Cisco 10G Catalyst 4500-X series switch is the highest throughput 10G Ethernet switch in the industry. It provides the high scalability, simplified network virtualization, application monitoring, and integrated network services for space-constrained environments in campus networks which meets the business growth objectives with unprecedented scalability. Some detailed information about Cisco 4500-X series switch and its optical solutions will be introduced to you, allowing you to easily deploy it in your network. Cisco 4500-X Series Switch The Cisco Catalyst 4500-X Series provides scalable, fixed-campus aggregation solutions in space-constrained environm…

Decoding the Wavelength in Fiber Optics

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Wavelength as we have been heard so many times in fiber optics, is not simply the term used to refine the color of the light. The light used in fiber optics in not the one that we can see by our eyes, as we use light in the infrared region which has wavelengths longer than visible light, typically around 850 nm, 1300 nm, 1550 nm. So why do we use infrared region? Why is 1550nm the most widely used wavelength in optical communication systems? What will happen if I transmit 850nm signal through a 1300nm optical fiber? This post has collected frequently asked questions about wavelength in fiber optics and provides the solutions to them, respectively. As we known that light is defined by its wavelength, namely it is a member of the frequency spectrum, and each frequency (sometimes also called color) of light has a wavelength associated with it. Wavelength and frequency are related, generally, the radiation of shorter wavelengths like light, UV and X-rays are identified by their wavelengt…

Do It Yourself for Your Home Network

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Due to continued questions on whether a home user is able to do his own cabling, or if they need to employ the services of a professional, this post is here to inform everyone of the information. For those who have little experience in telecommunication field, this is a complex task for them to sort it out. They should first find out the answers to the following questions: What are a home network’s basic elements?
Wired vs. Wireless – which to choose?
What cable should I used in home network? Finding out answers to these questions will go a long way toward ensuring that you build a network suitable for your home without spending too much in the process. What are the Basic Elements of a home network? A home network enables digital devices to share a broadband connection, information and communicate with each other. Installing a home network, there are several essential elements including cables, modem, router, switch, IP address, Wi-Fi and firewall. Of which modem, router and switch are …

Difference Between Twisted Pair Cable and Coaxial Cable

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A wire or cable is an indispensable element in communication system for connecting optical devices like optical transceivers, router and switch. Recently the most common cable types deployed in communication system are fiber optic cable, twisted pair cable and coaxial cable. Both twisted pair cable and coaxial cable are copper cables, so what’s the difference between them? This article may help you sort it out. Twisted Pair Twisted pair cables as the names implies, consists of a pair of cables twisted together, which has been utilized in telecommunication field for a long time. The twisting can avoid noise from outside sources and crosstalk on multi-pair cables, so this cable is best suited for carrying signals. Basically, twisted pair cable can be divided into two types: unshielded twisted-pair (UTP) and shielded twisted-pair (STP). UTP is for UNshielded, twisted pair, while STP is for shielded, twisted pair. UTP is what's typically installed by phone companies and data communica…

Graded Index or Step Index Multimode Fiber

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Fiber optic cable is the media of telecommunications infrastructure, enabling the transmission of high-speed voice, video, and data traffic in enterprise and service provider networks. We usually see single mode and multimode optic fibers available on the market with distinct specifications utilized in different network infrastructure. Compared with single mode fiber patch cables, multimode fiber has a larger core diameters, allowing for the larger numbers of modes. Owing to this, multimode fibers can be categorized into step-index fiber and graded-index fiber seen in Figure 1. This article will describe the main characteristics of optical fiber in general, and the comparison between step index and graded index fibers in particular. Quick Review of Fiber Optics Before moving on to the topic, let’s have a quick view of the basics of fiber optics. Optical fiber is a flexible filament of very clear glass capable of carrying information in the form of light. It is roughly the diameter of …

Wavelength-Converting Transponder in DWDM System

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Dense wavelength-division multiplexing (DWDM) as an emerging technology in fiber optic network, is devoted to increase the capacity of a single fiber, and thus the entire network in an cost effective way. A basic DWDM system typically includes these main components: a terminal multiplexer, an intermediate line repeater, and optical add-drop multiplexer (OADM), a terminal demultiplexer, and an optical supervisory channel. Transponders are currently a key element of the openness of DWDM systems that is used to convert incoming optical signals into the precise ITU-standard wavelengths to be multiplexed, which will be clearly discussed in this article. Introduction to DWDM Technology DADM technology is an extension of wavelength-division multiplexing (WDM) technology to arrange several fiber optic lights to transmit simultaneously via the same single fiber optic cable. Only one optical fiber is used between DWDM devices (per transmission direction). Instead of requiring one optical fiber …

What to Look Out for When Installing Buried Microduct?

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When it comes to FTTH deployment, most fiber jumper cables are complicated structures with tight buffered fibers and aramid fiber strength members inside plastic jackets. These cables are adequate for factory termination into prefabricated assemblies, which are not ideal for field termination or fast installation. Therefore network installers are turning to install microduct underground as it can be laid relatively quickly and does not require specialist fiber crews. Microducts (see in following picture) are typically small-diameter (typically 3 to 16 mm), flexible, or semi-flexible ducts designed to provide clean, continuous, low-friction paths for placing optical cables that have relatively low pulling tension limits. Unlike the conventional optical cables like SC to LC patch cable, microduct allows installation in existing underground duct. Up to four individual microducts can be installed depending on the diameter of the duct and the available space within the duct. Compared to i…

Understanding PoE Technology, and How to Deploy It

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What are the hottest technologies in today’s networking industry? Everyone may have his/her own ideas, but WiFi (wireless networking) and VoIP (Voice over Internet Protocol) are undoubtedly near the top. Recently, several enterprises announced plans for WiFi coverage and a global rollout of IP phones. WiFi and VoIP, in addition to being current industry buzzwords, also share another common attribute—they both require Ethernet and power to function. In 2003, the Institute of Electrical and Electronics Engineers (IEEE) released IEEE 802.3af, also known as the Power over Ethernet (PoE) standard, which provides a universal way to provide power and Ethernet-based data to a remote powered device over standard Ethernet cabling such as Cat5e or Cat6. Fiber optic cable like LC to FC patch cord is not suitable for PoE technology. This article will guide you through standard and method within PoE that will help you success in this field. What You Need to Know About PoE PoE is a standard allowing…