SFP+ Fiber Module or 10GBASE-T SFP+ for 10GbE Network?

The dramatic growth in data center requires the higher-performance servers, storage and interconnects. From initial 100M, 1G, 10G, to 40G and 100G, high speed Ethernet has never stopped developing. The standard for 10 Gigabit Ethernet (IEEE802.3ae) was ratified in 2002. In 10 Gigabit Ethernet, engineers often find it puzzled to choose a more suitable physical media between fiber and copper. Take a look at the media options for 10GbE Network.

Media Options for 10GbE Network
SFP+ Fiber Module

SFP+ (small form-factor pluggable plus) supports both fiber optic cables and DAC (direct attach cable). It delivers a wide variety of 10GbE Ethernet connectivity options for data center, enterprise wiring closet, and service provider transport applications. But it has the limitations that will prevent the media from moving to every server.

10GBASE SFP+ DAC

10G SFP+ cable is designed for 10GbE access layer interconnection in data center. It includes direct attach copper cables and active optical cables. DAC is a lower cost alternative to fiber, but it can support limited transmission distance and it’s not backward-compatible with existing GbE switches. DAC requires the purchase of an adapter card and requires a new top of rack (ToR) switch topology. DAC is more expensive than structured copper channels, and cannot be field terminated.

10GBASE-T SFP+

10GBase-T SFP+ enables 10GbE connections with unshielded or shielded twisted pair cables over distances up to 100 meters. 10GBase-T technology appears as SPF is not compatible with twisted pair cabling system typically used in data centers. With 10GBase-T SFP+, the migration from 1GbE to 10GbE can be easily achieved.

Comparison of SFP+ Fiber Module and 10GBase-T SFP+
Latency

Low latency becomes so important since the adoption of private cloud applications increases. It’s beneficial for ensuring fast response time and reducing CPU (center processing units) idle cycles so that improve data center efficiency.

As to 10GBASE-T SFP+, the physical connection (PHY) standard uses block encoding to transport data across the cable without errors. The block encoding requires a block of data to be read into the transmitter PHY, a mathematical function run on the data before the encoded data are sent over the link. It happens the same on the receiver side. This standard specifies 2.6 microseconds for the transmit-receive pair, and the block size requires latency to be less than 2 microseconds. While SFP+ fiber module applies simplified electronics without encoding, and common latency is around 300 nanoseconds per link.

You may think that two microseconds are not high. But what if a TOR infrastructure where traffic is passing 4 hops to reach the destination? 10.4-microsecond delay will be caused when using 10GBASE-T SFP+. The following table tells details about the latency of SFP+ DAC, SFP+ fiber module and 10GABSE-T SFP+ for different number of links.

Number of Links SFP+ DAC Latency SFP+ Fiber Module Latency 10GBASE-T SFP+ Latency
1 0.3 0.1 2.6
2 0.6 0.2 5.2
3 0.9 0.3 7.8
4 1.2 0.4 10.4
5 1.5 0.5 13.0
6 1.8 0.6 15.6

From the above table, it shows that the latency of 10GBASE-T SFP+ is the highest. As network links grow, the latency turns to be higher. It’s known that the lower latency, the faster the network speed. High latency in the data center infrastructure results in delays in CPU and application works, therefore limiting data center efficiency and increasing operational costs.

Power Consumption

Power consumption is also one of the important factors to be considered in data centers. Engineers are sensitive to power consumption and find a way to seek the lowest possible power consumption technologies. It’s said that every watt of power consumed, typically two additional watts are needed for cooling.

10GBase-T components today require anywhere from 2 to 5 watts per port at each end of the cable depending on the distance of the cable. But SFP+ fiber module requires about 0.7 watt regardless of distance. The figure below compares the power consumption of three media options of 10GbE Ethernet.

10GBASE-T-SFP-power consumption

From this figure, suppose there are 10000 ports in the data center, SFP+ fiber modules can greatly save the power. On contrary, 10GBASE-T components consumes the most power. Thus, to save power in the data center, SFP+ fiber modules and SFP+ DAC should better be selected when deploying thousands of cables in a data center.

Conclusion

From this article, SFP+ fiber modules and SFP+ DAC solutions are better than 10GBASE-T SFP+ for 10G data center. But 10GbE is not the ultimate goal. Besides factors mentioned in this article, you should also select a cabling solution which can support not only current needs but also future data center deployments when you design 10GbE network.

Originally published at http://www.fiber-optic-equipment.com

Dos & Don’ts of Cable Management

Just imagine how would you feel when you face cable spaghetti? You must say, “oh, it’s very annoying.” Yes, that’s right. Improper cabling can bring disadvantages like heat retention, untimely hardware failure and maintenance headaches. So how to avoid cable spaghetti and keep network cabling in a good organization?

nice-cabling

Since cable management is one of the most important factors of data center design, it’s necessary to master some cabling skills. The following content will give you some suggestions for cabling installation.

Don’t Pull Fiber Jumper Cables too Hard

When installing cables, pulling issue can’t be avoided. Pulling cables too hard can damage them by stressing the core. Stressing the core will affect the signal performance. In extreme cases, it will cause unwinding of the twists in the sheath. Under this situation, you should better buy high quality patch cords from reliable manufacturers or vendors. Good patch cords are able to withstand the stress. Because cheap cables have sub-standard sheathing and narrow diameter cores which can cause signal loss. A smaller core is also more fragile and weak, more likely to bend, leading to an increased rate of cable failure.

Don’t Ignore Labels

Cable labels are very likely to be ignored by engineers. After finishing cable installation, they always think they can remember every cable type, including the network cables, power cables, patch cables, etc. Things doesn’t happen like you wish. Your memory will disappear as time goes on. Thus, you should not overlook labeling which can help you identify cables in a short time and leave messages to other installers to easily decipher what goes back.

cable-label

Don’t Forget Cable Ties

Cable ties are cheap and useful to get a clean look of your data center. Today there are many categories in different sizes with many colors. Nylon and Velcro ties are the most two common kinds. Velcro ties are better than plastic ties because they are easy and quick to add, remove and reusable. Nylon cable ties can put mush stress on cable bundles and cause pressure points on the cable jacket, changing the cable geometry and thus decreasing performance. What’s more, Velcro ties can be cut easily to any length you need.

Measure the Exact Cable Length You Need

Usually it says the longer, the better. But it’s another case for network cabling. Improper cable length often causes cable mess. Suppose you have bought 50m patch cable. However, you just use 20m. Then how to deal with the spare 30m cable? Just leave it alone? Of course not. So you’re advised to measure the exact cable length you need. Custom cable is the best solution for you to get the right length.

Leave Space for Cables Trays

What if very long cables are left in your network system? You may consider to put the cables into the cable trays. But it’s not a good idea. Cable trays should not be overloaded. Suspended cable trays are mounted to a rack or something. If it’s too heavy, the cable trays may fall off and break other expensive things. Too many cables is not only safety problem, but also leads to poor operational practices because it’s too hard or fear of disturbing cables. What’s worse, the cables at the bottom of cable try may be crushed and degrade signal propagation.

Choose a Proper Cable Manager

Cable manager is an economical and efficient solution to manage high density structured cabling in data centers and telecommunication rooms, which allows the maximum amount of cables to be organized in a minimum amount of space. Choose the best cable manager which suits the most for your application. Simple or complex cable manager, vertical or horizontal, plastic or metal, one must meet your requirements for network cable management improvement.

cable-manager

Conclusion

Cable management is not an easy work. Some engineers may not take cable management seriously or they don’t care much if there is a little mess. But the improper operation can cause lots of problems. To achieve neat cabling, too many things must be taken into consideration. And some useful tools and equipment are also required. Come and find a perfect cabling solution.

Originally published at http://www.fiber-optic-equipment.com

LC Connectors for High Density Data Centers

SC duplex connector was popular a few years ago. But as time goes on, smaller and more compact cabling components are required since the packing density of optical devices keeps increasing, namely high density. The smaller the shape, the more popular the component, just like development history of cellphone. Driven by this requirement, optic manufacturers start to produce mini components. The most widely known is the LC connector, a small form factor connector. The following article will introduce various types of LC connectors in details.

Common LC Connector

LC small form factor connector has just 1.25mm ferrule, half the size of the standard connector (compared with SC connector). Because of the high density design, LC connector solution can reduce the space needed on racks, enclosures and panels by approximately 50% throughout the network. So LC connector is a good solution for high density data centers. The LC connector uses RJ45 push-pull style plug that offers a reassuring, audible click when engaged. It makes moves, adds and changes easy and saves costs for you. Besides, the protective cap completely covers the connector end, which prevents ferrule end face from contamination and impact and enhances the network performance.

lc-lc-duplex

LC Uniboot

LC uniboot connector includes a finger latch release that there is no need for tools when making the polarity change. Some LC uniboot connectors are color-coded and labeled “A” and “B” to provide visual references when making a polarity change. The uniboot design is compatible with transceivers using the LC interface. The LC uniboot patch cords use special round cable that allows duplex transmission within a single cable, and it greatly reduces cable congestion in racks and cabinets comparing to standard patch cords. LC uniboot patch cord is perfect for high density applications. FS.COM LC uniboot patch cords are available in SM, OM3 or OM4 multimode fiber types to meet a wide variety of configurations and requirements.

uniboot-lc

Push-Pull LC Connector

If you have tried to release LC connectors in patch panels with high density, you must know how difficult it is. As to high density panel, thumbs and forefingers can not easily access to pull the connector. So some manufacturers start to offer a special LC connector which can be easily dealt with. And that’s push-pull tab LC connector.

Push-Pull-Tab-Patch-Cable

LC push-pull connectors offer the easiest solution for installation and removal. The special design is available in a compact model, ideal for minimizing oversized panels. With this kind of connector, you don’t need to leave additional space at the top or bottom to allow room for engaging the latch. The structure of the LC push-pull compact is designed as the latch can be slid back, instead of being pushed down, to facilitate smooth removal. It’s simple for installation and removal. Push-Pull LC patch cable allows users accessibility in tight areas when deploying LC patch fields in high density data centers. Push-Pull LC fiber patch cords are available in OM4, OM3 or single-mode fiber types to meet the demands of Gigabit Ethernet, 10 Gigabit Ethernet and high speed Fibre Channel.

Secure Keyed LC Connector

Secure keyed LC connectors are designed for network security and stability. 12 colors are available in FS.COM, including red, magenta, pink, yellow, orange, turquoise, brown, olive, etc. Connections only work when the color matches. The color-coded keying options provide design flexibility and facilitate network administration. It reduces risks and increases the security of network from incorrect patching of circuits. Secure keyed LC connectors feature low insertion loss, excellent durability.

lc-keyed

Conclusion

This article tells different types LC connectors, including common LC connector, LC uniboot, push-pull LC and secure keyed LC connector. The design of those LC connectors keeps improving to adapt to high density data centers. Nowadays, the trend of network is high speed and high density. So effective cable management is significantly important. And the key concern is how to manage more cables within less space. Thus, among so many kinds of interfaces, LC connector is the most frequently used and the most effective solution for space saving in data centers.

Originally published at http://www.fiber-optic-equipment.com

Suggestions for Data Center Design

The demands on data centers and networks are growing very fast. To meet communication needs, more and more devices are connected to the data center network links. It brings difficulties in data center management. The infrastructure design should guarantee the reliable network performance. But how to achieve the best performance? Four suggestions are recommended for you when designing a data center.

Maximizing Network Performance

As today, many companies adopt high density configurations and virtualization to increase the capacity of existing IT equipment. To ensure the network performance, a robust data center infrastructure is necessary. And three parts of the infrastructure must be considered: the structured cabling, racks and cabinets, and the cable management.

data-center

Figure 1. Structured data center

First, the structured cabling performance has a close relationship to the connectivity and cable components. If the components fail to deliver good cabling system, great optical loss will be caused. To improve the channel performance, insertion loss should be minimized especially in 40G and 100G data center. Second, choose right rack or cabinet to accommodate new equipment with different size and weight requirements since active equipment in the infrastructure turn to be broken easily and will be replaced in five years or less. Third, manage the airflow and maintain good cooling system. Because the rising temperature of the data center has an influence on network performance. The last component of the infrastructure is cable management. A well-designed cable management should meet the standards of spare space, high reliability and scalability. The infrastructure is designed for both copper and fiber, maintaining proper bend radius for both copper and fiber, protecting cable from damage, and creating crosstalk and return loss.

Saving Time

Although data center grows in size and complexity, it often requires faster deployment. It must adapt to the rapid changing business requirements. As it says, time is money. Selecting an infrastructure that optimize time, result in faster deployments can save lots of costs.

In order to save time in deployment, installation and future moves, adds, and changes, a suitable modular solution based on the rack or cabinet should be applied. The modular solution is also good for effective airflow management and cooling, which can save time because it can easily support high density when needed. Pre-terminated copper and fiber cabling solutions can also save time during installation and future cabling moves. Pre-terminated fiber systems, for example, MPO to MPO trunk cables or MPO to LC harness cables, can facilitate the migration to higher speeds.

Optimizing Spare Space

To adapt to high speed demands, data center infrastructure turns to be more complex. Now space is a premium in the data center as port densities continue to increase. Considering the cost, infrastructure should be optimized for greater flexibility and scalability. High density connectivity options including high density patch panel, MTP cassette, etc. are the solutions to optimize space while supporting large port densities. For instance, LC connectors (2 fiber) have been replaced by MPO (typically 12 or 24 fibers) connectors for the migration from 10 GbE to 40 GbE and 100 GbE.

MTP-solution

Figure 2. MTP components for saving space

To optimize space in the data center, the following factors are needed to be considered:

  • Choose the rack or cabinet as your basic building block
  • Select racks and cabinets with higher weight limits, sufficient depth and heights that support growing vertically
  • Select cable management that can support existing and future cable density, fluent airflow, and is designed to support both copper and fiber
  • Select connectivity that supports high density and mixed media
  • Use cable with small outside diameter
  • Consider patching outside the rack and cabinet to save space for equipment
  • Select a rack or cabinet solution that easily integrates with overhead pathways
Finding a Cooperator With Rich Experience

During the design phase, the data center design must provide guaranteed performance while providing flexibility and scalability for future needs. During the installation phase, the solution must be easy to install, quick to deploy and easy to manage. So it’s important to find a qualified contractor who has a history of quality installations. You also need to choose a good manufacturer providing cost-effective components covering cooling, power, connectivity, cabling, racks and cabinets, cable management, and pathways, like Fiberstore (FS.COM). And the manufacturer should also have expertise of extending the equipment life, reducing cost and solving other problems in the data center.

Summary

Data center design is not an easy job as the cabling infrastructure becomes more complex for meeting the growing high data rates demands. To maximize the efficiency of a data center, too many elements should be taken into consideration. The above content gives suggestions for data center design to guarantee performance, save time, optimize space, and find an experienced cooperator. Hope this article is useful to your data center design.

Originally published at http://www.fiber-optic-equipment.com