Advantages and Disadvantages of OM5 Fiber in Data Center

As the continuously increased bandwidth demand, the types of fiber patch cable are also updating quickly. OM5 fiber cable, also known as WBMMF (wideband multimode fiber), has arrived to meet the growing bandwidth requirements. However, there are different opinions on whether the adoption of OM5 fiber will benefit today’s data center. This post will focus on the advantages and disadvantage that OM5 brings for data centers.

om5 patch cable

Trends in Data Center Deployment

With the cloud computing and web services continuing to drive bandwidth need, data rates grow from 10G, 40G to 100G and beyond in many data center networks. According to the Cisco global cloud index, nearly 99 percent of global traffic will pass through data centers by 2020. That means higher bandwidth, faster services and greater access are required for data center deployments. Therefore, advanced technologies including fiber patch cable and optical transceivers will be needed for performance-improving in data centers.

Will OM5 Fiber Benefit Data Center?

OM5 fiber is a new generation of multimode fiber. It was just standardized in several months ago. Different from OM1, OM2, OM3 and OM4, OM5 fiber is designed to work over a wide range of wavelengths between 850 nm and 950 nm. And it supports SWDM (shortwave wavelength division multiplexing) technology which can reduce fiber counts in optical transmission. Here are the advantages and disadvantages of OM5 fiber cable in data center.

om5 fiber cable

Advantages

Firstly, it cannot deny that the emergence of OM5 is to meet the high bandwidth challenges. At this point, OM5 will definitely benefit data centers in some degree. The main advantages are in the following part.

Compatibility—OM5 cable has the same fiber size of OM4 and OM3, which means OM5 is fully compatible with OM3 and OM4 fiber. In other words, OM5 cabling supports all legacy applications in existing data center infrastructures. If a service provider wants to use OM5 for high speed data center, big changes will not be needed for existing cabling.

Distance—multimode patch cord is often the first choice for short reach connections. As we know, OM4 patch cord can support link length up to 100m with 100G-SWDM4 transceivers. While OM5 can extend the reach to 150m with the same types of fiber optic transceivers, providing another better choice for data center optimization.

Cost—when it comes to data center building, the cost is an important parameter to consider. OM5 cable is beneficial for data center deployments. Compared to single mode fiber cable (SMF), multimode fiber cable (MMF) is more cost-effective, because in most data centers, short reach connection are common. Besides, OM5 provides optimal support of emerging SWDM applications which reduce the amount of fibers needed for high speed transmissions.

Disadvantages

Each coin has two sides. Though OM5 fiber cable can benefit data center building, there are still some problems at present. It’s known to us that OM5 has just been standardized earlier this year. Even though many optical vendors have introduced OM5 fiber patch cables, in the market, the price is a little higher than OM4. And the production of the corresponding optical transceiver like 100G-SWDM4 is still limited. All these restrict the further adoption of OM5 fiber cables.

Summary

It’s getting more costly for fiber optic cabling systems in data centers. As a new MMF type, OM5 offers improved performance over popular OM4 and OM3. With the development of OM5 technology, it will bring more benefits for data centers.

Point-to-Point VS Structured Cabling: Which One Is Best for You?

With the emergence of the Internet of Things, the cloud and mobility, much of the conversation about network connectivity is focused on wireless. However, cabling isn’t going away. Requirements are evolving, but cabling is still an essential component of any IT environment. Because the life-cycle of a cabling system is typically much longer than most of your IT infrastructure, it is important to understand the primary cabling methods and plan carefully. This article will make a comparison between two basic cabling methods: point-to-point cabling and structured cabling.

What Is Point-to-Point Cabling?

Point-to-point cabling refers to a data center cabling system comprised of “jumper” fiber cables that are used to connect one switch, server or storage unit directly to another switch, server or storage unit. A point-to-point cabling system is adequate for a small number of connections. However, as the number of connections in a data center increases, point-to-point cabling lacks the flexibility necessary when making additions, moves or changes to data center infrastructure. When the first data centers were built, end user terminals were connected via point-to-point connections. This was a viable option for small computer rooms with no foreseeable need for growth or reconfiguration. As computing needs increased and new equipment was added, these point-to-point connections resulted in cabling chaos with associated complexity and higher cost. Therefore, there is a downside to point-to-point cabling. However, the point-to-point cabling is surfacing again with the use of top of rack (ToR) and end of row (EoR) equipment mounting options. ToR and EoR equipment placement relies heavily on P2P cables, which can be problematic and costly if viewed as a replacement for standards-based structured cabling systems.

p2p cabling

What Is Structured Cabling?

As it has been mentioned before, point-to-point cabling had aroused many problems. In response, data center standards like TIA-942-A and ISO 24764 recommended a hierarchical structured cabling infrastructure for connecting equipment. Structured cabling is a comprehensive network of cables, equipment and management tools that enables the continuous flow of data, voice, video, security and wireless communications. Instead of point-to-point connections, structured cabling uses distribution areas that provide flexible, standards-based connections between equipment, such as connections from switches to servers, servers to storage devices and switches to switches. Structured cabling is designed to meet Electronic Industry Alliance/Telecommunications Industry Association (EIA/TIA) and American National Standards Institute (ANSI) standards related to design, installation, maintenance, documentation and system expansion. This helps to reduce costs and risk in increasingly complex IT environments.

Comparison Between Point-to-Point and Structured Cabling

Traditionally, point-to-point cabling has been used in the manufacturing sector to establish a direct connection between devices and automation and control systems. However, point-to-point cabling lacks the flexibility, reliability, manageability and performance required for the exploding number of connections within today’s networks.

Structured cabling provides the flexibility that point-to-point does not, as well as the capability to support future technologies, faster connections and more intelligent networks. Although structured cabling has long been the preferred approach in IT, we cannot deny point-to-point cabling completely. Here, the pros and cons of selecting a structured cabling implementation versus point-to-point implementation are listed in the picture below:

Conclusion

Cabling is among the most important considerations for organizations managing a data center, and investing in the right technologies to enable flexibility and optimal performance is key. Although there are several instances where point-to-point Top of Rack or End of Row connections make sense, an overall study that includes total equipment cost, port utilization, maintenance, and power cost over time should be undertaken—involving both facilities and networking—to make the best overall decision. On the whole, point-to-point cabling can present data center many problems. Structured cabling is a better choice over point-to-point cabling.

Introduction to WDM Transponders

With the development of wavelength-division multiplexing (WDM) technology, the network traffic volume is increasing and the demand for more network bandwidth is also on the rise. By converting the operating wavelength of the incoming bitstream to an ITU-compliant wavelength, WDM transponder serves as a key component in WDM system. As an important technology in the fiber optical network, WDM is moving beyond transport to become the basis of all-optical networking. And how to optimize WDM network has always been a hot topic. The transponder is a device to optimize the performance of WDM network, which plays an important in the whole system of WDM network. This article will introduce you the information on WDM transponders.

What Is a WDM Transponder?

Also called as an OEO (optical-electrical-optical) transponder, a WDM transponder is an optical-electrical-optical wavelength converter, which has been widely adopted in a variety of networks and applications. The picture below shows us how a bidirectional transponder works. In this picture, the transponder is located between a client device and a DWDM system. And we can see clearly that, from left to right, the transponder receives an optical bitstream operating at one particular wavelength (1310 nm), and then converts the operating wavelength of the incoming bitstream to an ITU-compliant wavelength and transmits its output into a DWDM system. On the receive side (right to left), the process is reversed. The transponder receives an ITU-compliant bit stream and converts the signals back to the wavelength used by the client device.

WDM transponder

The Application of a WDM Transponder

According to its function, the application of a WDM transponders can be classified into the following types.

  • Wavelength Conversion. It is known to us that when a CWDM Mux/Demux or DWDM Mux/Demux is added into a WDM network, there is a requirement to convert optical wavelengths like 850nm, 1310nm and 1550nm to CWDM or DWDM wavelengths. Then the OEO transponder comes to assist. The OEO transponder receives, amplifies and re-transmits the signal on a different wavelength without changing the signal content.
  • Fiber Mode Conversion. Multimode fiber optic cables (MMF) are often used in short distance transmission, while single-mode fiber optic cables (SMF) are applied in long optical transmission. Therefore, in some network deployment, considering the transmission distances, MMF to SMF or SMF to MMF conversions are needed. WDM transponders can convert both multimode fiber to single-mode fiber and dual fiber to single fiber.
  • Signal Repeating. In long haul fiber optic transmission, WDM transponder also can work as repeaters to extend network distance by converting wavelengths (1310nm to 1550nm) and amplifying optical power. The OEO converters convert the weak optical signals from the fiber into electrical signals, and regenerate or amplify, then recover them into strong optical signals for continuous transmission.
WDM Transponder and FMT Solution

At FS, OEO transponders are made into small plug-in cards to be used on the FMT platform. FMT platform makes devices like EDFA, OEO, DCM, OLP and VOA into plug-in cards and provides standard rack units as well as free software to achieve better management and monitoring. In addition, FMT series products like OEO, DCM and OLP also have higher performance than that of old ones. FMT series OEO transponder can convert optical signals into DWDM wavelengths, reducing the fault risk caused by high power consumption of DWDM fiber optic transceiver. Since the OEO transponder is made into small plug-in card in the FMT platform, it only occupies one slot in the special designed chassis when installed, thus saving a lot of space. In addition, all these FMT plug-in cards, including OEO, in a rack unit share the same power source and support hot plug & play operation. And they can be inserted or removed flexibly in the racks for DWDM networking.

FMT

Conclusion

Since the OEO transponder plays an important role in WDM network, such as receiving, amplifying and re-transmitting the signal on a different wavelength, adding an OEO transponder into the WDM network is very essential. The OEO transponders in our FMT series are made into small plug-in cards with high quality to ensure good transmission performance. For more information on our FMT system, please visit www.fs.com.

Data Centers: Say Hello to White Box Switch

Today, nearly all mainstream organizations use traditional (integrated) switches from vendors like Cisco, HP, Arista and Juniper. However, hyperscale folks such as Google, Amazon and Facebook are taking the lead to use white box switch in the portion of their networks, operating the system in a different manner. So what is the magic behind that? Are these OTTs the only customers of white box switch? You may find some hints in this article.

White Box Switch

What Makes White Box Switch Special?
White box switches consists of generic and inexpensive hardware and a preload network operating system (NOS) that can be purchased and installed separately. Often the hardware and software come from different vendors. This is in contrast to a traditional switch that comes as one package including the hardware and the software. For example, when you buy a catalyst switch from Cisco, you are obliged to use Cisco IOS as its operating system. But with white box switch, you are allowed to buy hardware and software separately.

Except offering increased software flexibility/programmability and reduced vendor lock-in, white box switch enables users to have multiple choices on hardware, network operating system (NOS) and applications. The impact of which is profound when it comes to network orchestration, routing, automation, monitoring and network overlay.
White Box Switch NOS

What About the Target Market of White Box Switch?
White box switch is initially designed for data centers. Companies that operating mega data centers are especially prefer white box switch for at least two reasons: these companies generally demand for massive deployment of switches and the port density of each switch needs to be high. White boxes are cheaper while offering high-density ports, hence proven to be an optimal alternative. On the other hand, these large-scale companies also value the flexibility and openness of the switch platform, besides CAPEX savings. As an open platform to offer broader flexibility, white box switch free them from traditional L2/L3 protocols, enabling more possibilities to develop and support any SDN based networking.

So, are these large-scale OTTs the only target market for the white box switch? Definitely No!

Any small or medium-sized cloud based providers, or data center of service providers can consider deploy white box switches in data centers, concerning the cost savings and enhanced flexibilities compared with traditional switches. Also because of the familiar IT tools/ commands their technicians are used to. However, white box switches are not yet ready to offer all features and services that a service provider needs to offer, and not yet for deployment in non data center environments.

The Potential of White Box Switch
Based on an open platform, white box switch offers greater possibilities for innovation when compared with traditional networking gears. As the number of vendors that specialized in developing software began to soar, customers can choose from a range of software solutions with added functionality and reduced price.

White box switch becomes even popular in this age of SDN. In traditional switches, software and hardware are integrated into one package, which limits the network innovation greatly. SDN is here to decouple the software from hardware, helping speed shifts in networking. It resembles the standpoint of white box switching. Moreover, the advert of SDN also drives white box forward: when combined with SDN-centric designs, these deployments have resulted in dramatic improvements in automation, operational simplification, and faster innovation. These benefits are now being realized by enterprises of all sizes via commercially available SDN solutions.

Conclusion
Despite the fact that white box switches cannot be applied in non-data center environment for the time being, they are meeting their target market requirements successfully. The potential of white box switch cannot easily be underestimate, it is an ideal alternative that worth to be seriously considered at least for data center applications.

Brief Introduction to EDFA

In fiber optic communication systems, problems arise from the fact that no fiber material is perfectly transparent. The visible-light or infrared beams carried by a fiber are attenuated as they travel through the material. This necessitates the use of optical amplifiers. And EDFA (Erbium Doped Fiber Amplifier) is a representative one in the optical amplifier. There is one saying that EDFA is the most popular optical amplifier in optical network communications. Next, we will begin with the definition of EDFA.

The Definition of EDFA

An EDFA, also called optical amplifier or an erbium-doped fiber amplifier or erbium amplifier, is an optical or IR (Infrared Radiation) repeater that amplifies a modulated laser beam directly, without opto-electronic and electro-optical conversion. The device uses a short length of optical fiber doped with the rare-earth element erbium. When the signal-carrying laser beams pass through this fiber, external energy is applied, usually at IR wavelengths. This so-called pumping excites the atoms in the erbium-doped section of optical fiber, increasing the intensity of the laser beams passing through. The beams emerging from the EDFA retain all of their original modulation characteristics, but are brighter than the input beams.

Three Major Applications for Optical AmplifierThree Major Applications for Optical Amplifier

The above picture illustrates the three major applications for optical fiber amplifiers: booster, in-line amplifier, and pre-amplifier. These applications are described in more details below:

Booster Amplifier

Booster amplifiers are placed directly after the optical transmitter. In this application, booster amplifier is adopted to compensate for the losses of optical elements between the laser and optical fibers so that the increased transmitter power can be used to go further in the link.

In-line Amplifier

In-line amplifiers or in-line repeaters are placed along the transmission link to compensate for the losses incurred during propagation of optical signal. They take a small input signal and boost it for re-transmission down the fiber. Here it should also be pointed out that to control the signal performance and the noise added by the EDFA is important, because noise added by amplifier will limit the system length.

Pre-amplifier

Pre-amplifiers are placed just before the receiver to increase the signal level before the photodetection takes place in an ultra-long haul system so as to improve receiver sensitivity. By placing a pre-amplifier, a much larger signal can be presented to the receiver, thus easing the demands of the receiver design.

Top EDFA Products Overview

By now, you should have a basic idea of what an EDFA is and what it is used for, next I will introduce you some truly excellent EDFA products on the market.

Type
Description
22dBm Output Booster DWDM EDFA C-band 24dB Gain, 1U Rack Mount
16dBm Output Mid-stage DWDM EDFA C-band 26dB Gain, Plug-in Card for FMT Multi-Service Transport System
17dBm Output Mid-stage DWDM EDFA C-band 17dB Gain, Plug-in Card for FMT Multi-Service Transport System
Conclusion

Of the various technologies available for optical amplifiers, EDFA technology is the most advanced, and consequently the vast majority of optical amplifiers are designed based on this technology. In addition, the combination of reliable performance and relatively low cost allows EDFA to be widely deployed in modern optical networks.