Pros & Cons of Fiber Optic Networks

petak , 01.07.2016.

As one of the latest and most popular technologies utilized for information transmission from one point to another, the fiber optic communication has gained more and more importance in data centers nowadays. Since its introduction, fiber optic communication has revolutionized the telecommunications industry, transforming into the fiber optic broadband Internet service enjoyed by people today. With the obvious advantages, fiber optic cables have become an essential component in fiber optic communications. Terminated with connectors on ends, these cables (e.g. SC SC fiber cable) carry the light signals generated by the transmitter to the receiver. Although this fiber optic connection has been widely used in data centers because of its high data transmission speeds over long distance, fiber optics, like many other things, also has two sides: the pros and cons. Here this article delves into the advantages and disadvantages of fiber optic networks.

Pros of Fiber Optics
Great Immunity & High-quality Connections: Since the fiber core is made of glass, which is an insulator, no electric current can flow through. It’s immune to electrometric interference and radio-frequency interference (EMI/RFI), crosstalk, impedance problems, and more. More specifically, fiber optics are highly resistant to EMI and have a low rate of bit error. EMI is a disturbance caused by electromagnetic radiation from an external source. This disturbance can interrupt or degrade the performance of a conventional metallic cable connection and can be caused by an object that carries electrical currents, such as power lines or even the sun. Fiber optics are also resistant to corrosion, making them a good option for beachfront properties where copper cabling would otherwise be susceptible to degradation by salt and seawater.

Great Security: Security is a major concern for some companies, enterprises or organizations, whether small or big. With fiber optic cables, the data carried on are very safe. Fiber optics don’t radiate signals and it’s really difficult to tap or listen in the passed through information. Besides, once there occurs any physical break, it’s extremely to identify since this break will have impacts on the whole system. Fiber optic networks also enable you to put all your electronics and hardware in one central location, instead of having wiring closets with equipment throughout the building.

Scalability & Design: Fiber optics are much more scalable in nature as new equipment can be added easily and laid over the original fiber. Wavelengths can be turned on or off on demand, which allows for the easy provisioning of services and quick scaling for a growing business. Fiber optic cables are also much smaller in size and lighter weight than copper wiring. These fibers can typically be put in place in preparation for growth needs up to 15 to 20 years in the future. Although growth is often speculative, spare fibers can be included for future requirements to accommodate growth. Alternatively, additional cables can be put in place at a later time to make way for network expansion.

Cons of Fiber Optics
It’s well known that fiber optic cable provides more bandwidth than copper, and can carry more information with greater fidelity than copper wire. And no one can defy its advantages. But it’s also clear that fiber optic networks have several weak points.

Physical Damage: As mentioned above, fiber optic cable is thinner and lighter than copper wiring, so it makes for a more delicate system. Just because of its small size, fiber optic cable can be easily cut by accident during building renovations or rewiring. In addition, as fiber optic cables can transmit much more data than metallic networks, you would need fewer cables to service a larger number of people. This means that cutting just one cable could disrupt service for a large number of businesses and individuals. Additionally, wildlife also poses a threat, as the fiber cable jackets are intriguing to some species. Tunneling animals and rodents may chew through the cable, while many insects can find the cabling palatable. Anything that can wrap itself around the cable can also cut off the transmission. Fibers are also sensitive to bending, making laying fibers around corners a tricky business. Fiber optic networks are also susceptible to radiation damage or chemical exposure.


Fiber Fuse: At high power, fiber optic networks are susceptible to something known in the industry as “fiber fuse”. This occurs when too much light meets with an imperfection in the fiber, which can destroy long lengths of cable in a short amount of time.

Short-Term Large Budget: Judging from the long-term running, it’s cost-effective. But when considering for short-term use, it’s costly to implement fiber optic systems. Special test equipment is often required along with installers that have skilled knowledge about laying a fiber optic network. Fiber endpoints and connection nexuses also require special equipment and setup. In addition, it may take specialized equipment to diagnose an issue with a fiber optics network, making for higher-cost fixes if the cables sustain damage.

Conclusion
Although there some several weaknesses, fiber optics technology has still dominated the telecommunication market. And fiber optic network is selected as the main communication way. To ensure efficient fiber optic network, it’s important to choose the high-quality fiber optic products. Here Fiberstore is highly recommended for its reliable products, including optical transceivers (say SFP modules), fiber optic cables (SC SC fiber cable), as well as testing equipment used in cable installation, and so on. You can try it!

Oznake: fiber optics, fiber optic cables, SC SC fiber cable, optical transceivers, SFP+ modules

Why Choose 10 Gigabit Ethernet?

srijeda , 13.04.2016.

Since Ethernet technology came into people's use in 1970s, Gigabit Ethernet (GbE) has long deminated the local area network (LAN) applications. But when to connect servers to storage area networks (SANs) and network attached storage (NAS) or for server-to-server connections, GbE seems to be not sufficient enough. In such a case, Ethernet has developed the later technology standard as newer, higher performing iteration—10GbE.

The Institute of Electrical and Electronics Engineers (IEEE) 802.3 working group has published several standards regarding 10GbE, including 802.3ae-2002 (fiber -SR, -LR, -ER), 802.3ak-2004 (CX4 copper twin-ax InfiniBand type cable), etc. Among these standard interfaces, 10GBASE-SR is the most-widely used type, like Cisco SFP-10G-SR and Cisco SFP-10G-SR-S. With 10Gigabit connectivity becoming widely available, 10GbE technology has emerged as the connection choice for many companies to grow their networks and support new applications and traffic types. Behind the 10GbE, there are three main advantages which explain why users choose it today.

Data Center Network Simplification
While Fibre Channel and InfiniBand are specialized technologies that can connect servers and storage, they can’t extend beyond the data center. However, a single 10GbE network and a single switch can support the LAN, server-to-server communications, and can connect to the wide-area network. Ethernet and IP network technology are familiar to network designers, so replacing multiple networks with a single 10GbE network avoids complex staff training. And by consolidating multiple gigabit ports into a single 10gigabit connection, 10GbE simplifies the network infrastructure while providing greater bandwidth.

Traffic Prioritization and Control
A major advantage of 10GbE is that separate networks for SANs, server-to-server communication and the LAN can be replaced with a single 10GbE network. While 10Gb links may have sufficient bandwidth to carry all three types of data, bursts of traffic can overwhelm a switch or endpoint.

SAN performance is extremely sensitive to delay. Slowing down access to storage has an impact on server and application performance. Server-to-server traffic also suffers from delays, while LAN traffic is less sensitive. There must be a mechanism to allocate priority to critical traffic while lower-priority data waits until the link is available.

Existing Ethernet protocols do not provide the controls needed. A receiving node can send an 802.3x PAUSE command to stop the flow of packets, but PAUSE stops all packets. 802.1p was developed in the 1990s to provide a method to classify packets into one of eight priority levels. However, it did not include a mechanism to pause individual levels. The IEEE is now developing 802.1Qbb Priority-based Flow Control (PFC) to provide a way to stop the flow of low-priority packets while permitting high-priority data to flow.

A bandwidth allocation mechanism is also required. 802.1Qaz Enhanced Transmission Selection (ETS) provides a way to group one or more 802.1p priorities into a priority group. All of the priority levels within a group should require the same level of service. Each priority group is then assigned a percentage allocation of the link. One special priority group is never limited and can override all other allocations and consume the entire bandwidth of the link. During periods when high-priority groups are not using their allocated bandwidth, lower-priority groups are allowed to use the available bandwidth.

Congestion control
802.1Qbb and 802.1Qaz by themselves don't solve the packet loss problem. They can pause low-priority traffic on a link, but they don't prevent congestion when a switch or an end node is being overwhelmed by high-priority packets from two or more links. There must be a way for receiving nodes to notify sending nodes to slow their rate of transmission.

IEEE 802.1Qau provides such a mechanism. When a receiving node detects that it is nearing the point where it will begin discarding incoming packets, it sends a message to all nodes currently sending to it. Sending nodes slow their transmission rate. Then, when congestion is cleared, the node sends a message informing senders to resume their full rate.

10GbE in Data Centers
For many institutions, especially those that utilize automated trading, uptime and response time is critical. Longer delays than a second can be exceedingly costly. With servers now being able to transmit bandwidth and network downtime, today’s data centers of some companies need extended bandwidth. 10GbE is an ideal technology to move large amounts of data quickly. The bandwidth it provides in conjunction with server consolidation is highly advantageous for Web caching, real-time application response, parallel processing and storage.

Conclusion
10GbE comes as the ideal connection choice for some companies, delivering greater bandwidth for sending data over Ethernet architectures with reduced cost and complexity. Fiberstore offers an ocean of 10GbE solutions, such as high-quality SFP+ modules (eg. Cisco SFP-10G-SR and SFP-10G-SR-S mentioned above). For more information about 10GbE equipment, you can visit Fiberstore or directly connect me at Linkedin @Fern Xu (Fiberstore).

Oznake: 10GbE, 10GBASE SR, Cisco SFP-10G-SR, Cisco SFP-10G-SR-S, SFP+ modules