Data Center 10 Gigabit Ethernet Cabling Options

With the dramatic growth in data center throughput, the usage and demand for higher-performance servers, storage and interconnects have also increased. As a result, the expansion of higher speed Ethernet solutions, especially 10 and 40 Gigabit Ethernet has been ongoing. For 10 Gigabit Ethernet solution, selecting the appropriate 10-gigabit physical media is a challenge, because 10GbE is offered in two broad categories: optical and copper. This article will introduce both optical and copper cabling options for 10 Gigabit Ethernet.

Fiber Optic Cables

Two general types of fiber optic cables are available: single-mode fiber and multimode fiber.

Single-mode Fiber (SMF), typically with an optical core of approximately 9 μm (microns), has lower modal dispersion than multimode fiber. It is able to support distances of at least 10 kilometers, depending on transmission speed, transceivers and the buffer credits allocated in the switches.

Multimode Fiber (MMF), with an optical core of either 50 μm or 62.5 μm, can support distances up to 600 meters, depending on transmission speed and transceivers. 

When planning data center cabling requirements, be sure to consider that a service life of 15-20 years can be expected for fiber optic cabling. Thus the cable chosen should support legacy, current and emerging data rates.

10GBASE-SR — a port type for multimode fiber, 10GBASE-SR cable is the most common type for fiber optic 10GbE cable. It is able to support an SFP+ connector with an optical transceiver rated for 10GbE transmission speed. 10GBASE-SR cable is known as “short reach” fiber optic cable.

10GBASE-LR — a port type for single-mode fiber, 10GBASE-LR cable is the “long reach” fiber optic cable. It is able to support a link length of 10 kilometers.

OM3 and OM4 are multimode cables that are “laser optimized” and support 10GbE applications. The transmission distance can be up to 300 m and 400 m respectively.

Copper Cables

Common forms of 10GbE copper cables are as follows:

10GBASE-CR — the most common type of copper 10GbE cable, 10GBASE-CR cable uses an attached SFP+ connector and it is also known as a SFP+ Direct Attach Copper (DAC). This fits into the same form factor connector and housing as the fiber optic cables with SFP+ connectors. Many 10GbE switches accept cables with SFP+ connectors, which support both copper and fiber optic cables.

Passive and Active DAC — passive copper connections are common with many interfaces. As the transfer rates increase, passive copper does not provide the distance needed and takes up too much physical space. So the industry is moving towards an active copper type of interface for higher speed connections. Active copper connections include components that boost the signal, reduce the noise and work with smaller gauge cables, improving signal distance, cable flexibility and airflow.

10GBASE-T — 10GBASE-T cables are Cat6a (category 6 augmented). Supporting the higher frequencies required for 10GbE transmission, category 6a is required to reach the distance of 100 meters (330 feet). Cables must be certified to at least 500 MHz to ensure 10GBASE-T compliance. Cat 6 cables may work in 10GBASE-T deployments up to 55 meters (180 feet) depending on the quality of installation. Some 10GbE switches support 10GBASE-T (RJ45) connectors.

When to Use Different Type of 10GbE Cables

To summarize, currently the most common types of 10GbE cables use SFP+ connectors.

• For short distances, such as within a rack or to a nearby rack, use DAC with SFP+ connectors, also known as 10GBASE-CR.
• For mid-range distances, use laser optimized multimode fiber cables, either OM3 or OM4, with SFP+ connectors.
• For long-range distances, use single-mode fiber optic cables, also known as 10GBASE-LR. 

Originally published: www.fiber-optic-components.com/data-center-10-gigabit-ethernet-cabling-options.html

How to Achieve a Reliable, Affordable and Simple 10 Gigabit Ethernet Deployment?

10 Gigabit Ethernet, or 10GE and 10GbE, is a group of computer networking technologies for transmitting Ethernet frames at a rate of 10 gigabits per second. Nowadays, 10 Gigabit Ethernet is gaining broader deployments by the increasing bandwidth requirements and the growth of enterprise applications. But there is a question to be considered when deploying 10 Gigabit Ethernet — how to achieve a reliable, affordable and simple 10 Gigabit Ethernet deployment? The text below will tell the answer.

10 Gigabit Ethernet and the Server Edge: Better Efficiency

Server virtualization supports several applications and operating systems on a single server by defining multiple virtual machines on the server. Virtual machines grow and require larger amounts of storage than one physical server can provide. Storage area networks (SANs) or network attached storage (NAS) provide additional and dedicated storage for virtual machines. But connectivity between the servers and storage must be fast to avoid bottlenecks. 10 Gigabit Ethernet is able to provide fastest interconnectivity for virtualized environments.

10 Gigabit Ethernet SAN versus Fibre Channel: Simpler and More Cost-effective

The Internet Small Computer System Interface (iSCSI), an extension of SCSI protocol used for block transfers in most storage devices and Fibre Channel, is making 10 Gigabit Ethernet an attractive, alternative interconnect fabric for SAN applications. The iSCSI capabilities allow 10 Gigabit Ethernet to compare very favorably to Fibre Channel as a SAN interconnect fabric. 10GbE networking can reduce equipment and management costs as its components are less expensive than highly specialized Fibre Channel components and do not require a specialized skill set for installation and management.

10 Gigabit Ethernet and the Aggregation Layer: Reduce Bottlenecks

10 Gigabit Ethernet allows the aggregation layer to scale to meet the increasing demands of users and applications. It can help bring oversubscription ratios back in line with network-design best practices, and provides some important advantages over aggregating multiple Gigabit Ethernet link, such as less fiber usage, greater support for large streams and longer deployment lifetimes.

10 Gigabit Ethernet and Fiber Cabling Choices

For any fiber cable deployment, the types of fiber cable, 10 Gigabit Ethernet physical interface and optics module form factor need to be considered. Form factor options are interoperable as long as the 10 Gigabit Ethernet physical interface type is the same on both ends of the fiber link.

10 Gigabit Ethernet and Copper Cabling Choices

Currently, three different copper cabling technologies for 10 Gigabit Ethernet are available. 10GBASE-CX4 was the first 10 Gigabit Ethernet copper standard. CX4 was relatively economical and allowed for very low latency. Its disadvantage was a too-large form factor for high density port counts in aggregation switches. SFP+ direct attach cables (DAC) connect directly into an SFP+ housing. It has become the connectivity of choice for servers and storage devices in a rack due to its low latency, small form factor and reasonable cost. 10GBASE-T is able to run 10 Gigabit Ethernet over CAT6a and CAT7 copper cabling up to 100 meters, but it needs technology improvements to lower its cost, power consumption and latency.

10 Gigabit Ethernet and the SFP+ Makeover: Direct Attach Cables are convenient for Short Runs

SFP+ direct attach cables integrate SFP+ connectors with a copper cable into a low-latency, energy-efficient, and low-cost solution. Direct attach cables are currently the best cabling option for short 10 Gigabit Ethernet connections.

10 Gigabit Ethernet and Link Aggregation Offers Redundancy and Resiliency

The Link Aggregation Control Protocol (LACP) standard defines a way of bundling several physical ports over one logical channel. From a deployment standpoint, it is far easier to implement a distributed LACP solution with stackable switches that allow link aggregation across the stack. In this configuration, the stack acts as a single logical switch and link aggregation is seamless.

10 Gigabit Ethernet and Top-of-Rack Best Practice

The diagram below shows a stackable 10 Gigabit Ethernet ToR switching solution enabling cost-effective SAN connectivity for servers and network storage. In addition to better performance, LACP functionality provides better availability and redundancy for servers and storage. Moreover, it provides failover protection if one physical link goes down, while iSCSI traffic load balancing ensures greater transmission throughput with lower latency.

10 Gigabit Ethernet and Distribution Layer Best Practice

The diagram below shows Gigabit access switches with 10 Gigabit uplinks and stackable 10 Gigabit aggregation switches. At the edge, stacks of access switches are virtualized into a single switch, reducing configuration and management overhead.

To achieve a reliable, affordable and simple 10 Gigabit Ethernet deployment, the factors stated above need to be considered. Fiberstore SFP+ transceivers and SFP+ direct attach cables are ideal for cost-sensitive organizations considering 10 Gigabit Ethernet applications and they help growing companies support rising bandwidth requirements, new applications, and the demands of a fast-paced business environment.

Fiberstore Passive Optical Components Solution

Passive optical components market is propelled by the accelerating bandwidth requirements coupled with the growth of passive optical network (PON). Usage of passive optical components to obtain energy efficient network solutions is gaining popularity. This article will introduce some Fiberstore passive optical components.

Optical Attenuators: an optical attenuator is a device that is used to reduce the power level of an optical signal. Optical attenuators are commonly used in fiber optic communications, either to test power level margins by temporarily adding a calibrated amount of signal loss, or installed permanently to properly match transmitter and receiver levels.

Optical Circulator: an optical circulator is a multi-port (minimum three ports) non-reciprocal passive component. The function of an optical circulator is similar to that of a microwave circulator — to transmit a light wave from one port to the next sequential port with a maximum intensity, but at the same time to block any light transmission from one port to the previous port.

Fiber Collimator: a fiber collimator is a device for collimating the light coming from a fiber, or for launching collimated light into the fiber. It is used to expand and collimate the output light at the fiber end, or to couple light beams between two fibers. Both single-mode fiber collimators and multimode fiber collimators are available.

Optical Isolator: an optical isolator is a passive optical component that allows light to propagate in only one direction. Optical isolators are typically used to protect light sources from back reflections or signals that can cause instabilities and damage. The operation of optical isolators depends on the Faraday effect, which is used in the main component, the Faraday rotator.

Fiber Optic Sensor: a fiber optic sensor is a sensor that uses optical fiber either as the sensing element (intrinsic sensors), or as a means of relaying signals from a remote sensor to the electronics that process the signals (extrinsic sensors). Fiber optic sensors are immune to electromagnetic interference, and do not conduct electricity so they can be used in places where there is high voltage electricity or flammable material such as jet fuel.

Pump Combiner: a pump combiner is a passive optical component built based on fused biconical taper (FBT) technique. Pump combiners are widely used in fiber laser, fiber amplifier, high power EDFA, biomedical and sensor system etc. Three types of pump combiners are available: Nx1 Multimode Pump Combiner, (N+1)x1 Multimode Pump and Signal Combiner, PM(N+1)x1 PM Pump and Signal Combiner.

Polarization Components: polarization is the state of the e-vector orientation. Polarization components are used to isolate and transmit a single state of polarized light while absorbing, reflecting, and deviating light with the orthogonal state of polarization. Polarization components can be utilized in high power optical amplifiers and optical transmission system, test and measurement.

Fiberstore has all of the above passive optical components with high quality and reasonable price. You can select excellent passive optical components or other optical products for your network at www.fs.com.

Article source: www.fiber-optic-components.com/fiberstore-passive-optical-components-solution.html

OTDR, LTS and Source&Meter: Which Is Better for You?

As the technology advances further, the kinds of fiber optic testers also have increased. The variety of choices of such devices can be overwhelming to a would-be buyer. This paper will introduce you some common types, such as OTDR (optical time domain reflectometer), LTS (loss test set) and Source & Meter. But there is a problem you should know that the function of them is very similar since they all can be used to test cable installation or outside plant applications. As a result, it would be hard for us to select the right one for detecting our fiber optic events. Under this circumstances, here comes the question: OTDR, LTS and Source&Meter, which is better?

Introduction to OTDR, LTS and Source&Meter

Before you know how to choose the right one from these fiber optic testers, you must have a basic knowledge of them. So next, OTDR (optical time domain reflectometer), LTS (loss test set) and Source & Meter, each of them would be given a brief introduction.

OTDR - OTDR is essentially an optical radar. It sends pulses of light into optical fibers, and then analyzes the minuscule amounts of light which is reflected back to them. Also, complex computations are used to determine the size and distance to events encountered in the fiber run. Events are defined as losses or changes in the fiber’s light-carrying capacity.

 

LTS - In the heart of the LTS, it is the combination of a power meter and light source. Measurements are made with a two stage process. First the source power is measured, then light is put through the device to be tested, and a second measurement is made. The difference in the measurements is the device loss.

Source & Meter - Sources and Meters perform the same functions as an LTS. But compared with LTS, it has greater flexibility since a single source and meter pair can also be used at each end of a link.

OTDR, LTS and Source&Meter: Which Is Better

After knowing about the basic knowledge about these fiber optic testers, there are some features of them you should know so that you can choose the right fiber optic tester for your fiber networks.

Cost - Compared to a loss test set or source & meter, OTDR requires more technical expertise which determines it has higher labor expense. What is more, it has high asset expense and administration expense. So if you plan to use an OTDR frequently, it makes sense to buy one. If not, you had better rent one to reduce cost. As to LTS and Source & Meter, one LTS may be cheaper than a source / meter pair. Because it has less inventory to maintain and deploy, that is why its ongoing costs is lower.

Ease of use - OTDR readings must be analyzed and interpreted by trained and experienced people. It’s difficult for a less qualified installer to operate an OTDR and make sense out of it. As a result, using this device can require considerable time and effort. But LTS is the simplest way to ensure that connections are up to standard, and is widely used by almost everyone involved in hands-on work. Source & Meter is slightly harder to use when compared with LTS in that it does not have some sorts of automated wavelength synchronisation.

Application - OTDR is designed for outside plant (OSP) applications. Most OSP installations involve splicing single-mode fiber to get longer runs and the OTDR allows verifying the quality of the splice. But when that link is finished, it must still be tested for insertion loss with a light source, power meter and reference cables, just like premises cables. Premises cables rarely have splices and are short, often too short for the OTDR to measure. LTS can be used to simply and reliably measure end to end loss of installed systems, preferably using a bi-directional or two-way method at multiple wavelengths, with minimum inventory and modest technician skill levels. The use of Source & Meter is more flexibility. One source & meter can measure a link, whereas two LTS (Loss Test Set) instruments are needed. And a source is not needed to do transmission power measurements, so it can be used elsewhere.

From the above analysis, we can see that the cost of OTDR is the highest, and it is more suitable for experts to use. While the cost of LTS is the lowest, and it s relatively simple to use. Source & Meter is between them. In a word, these fiber optic testers are all indispensable instruments that can illuminate problems in your optical fiber before they bring your system to its knees. Once you are familiar with the features of them, you will be prepared to choose the right one to detect and eliminate your optical fiber events.

Article Source: www.chinacablesbuy.com/otdr-lts-and-sourcemeter-which-is-better-for-you.html