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Leads to buy the best quality Singlemode Fiber Optic Patch cables?

Many people would answer yes to this question, as from first glance they all look physically similar. However, upon closer inspection and by measuring performance, it is quite obvious that the quality can vary greatly.

For many people in the IT and telecoms industry, a fibre optic patch lead (also known as an optic fibre patch cord) is now considered a commodity item.

However, when choosing to buy the best quality singlemode fibre optic patch leads, the following should be considered:

What is Fibre Optic Patch Lead Connector Grade (Performance)?

IEC standards dictate the connector performance requirement for each grade of fibre optic patch lead connector. These standards guide end users and manufacturers in ensuring compliance with best practices in optical fibre technology.

Generally, Grade A, B or C options are available, with Grade A providing the best performance.

According to IEC 61753 and IEC 61300-3-34 Attenuation Random Testing Method, ‘Grade C’ connectors have the following performance characteristics: Attenuation: 0.25dB mean, >0.50dB max, for >97% of samples. Return Loss: >35dB.

‘Grade B’ connectors have the following performance characteristics: Attenuation: 0.12dB mean, >0.25dB max, for >97% of samples. Return Loss: >45dB.

‘Grade A’ connector performance (which is still yet to be officially ratified by IEC) has the following performance characteristics: Attenuation: 0.07dB mean, >0.15dB max, for >97% of samples. While the Return Loss using IEC 61300-3-6 Random Mated Method is >55dB (unmated – only angled connectors) and >60dB (mated), this performance level is generally available for LC, A/SC, SC and E2000 interfaces.

What Singlemode Optic Fibre Types are available?

For singlemode fibre optic patch leads, two fibre types are generally available, G652D or G657A2.

G652D and G657A2 specifications refer to the glass and cable construction of optical fibre and are generally the fibres of choice in optical fibre patch leads for singlemode systems.

657A2 optical fibre in patch leads, provide an improved bend radius and flexibility, which may allow for better cable management and routing in congested areas. The improved bend radius may also allow for increased density in high-density patching fields. G657A2 optical fibre is becoming very popular in Data Centre and Enterprise network deployments.

What are Optical Fibre Connector types?

For singlemode optical fibre patch leads, the following connector types are available, LC, SC, SC/A, ST, FC, E2000.

The most common types of connectors used in modern transmission systems are SC, SC/A and LC (either simplex or duplex connectors).

Selecting the correct patch lead connector type is usually dictated by the transmission equipment or patch panel that the patch lead needs to connect with.

Why the Optical Fibre Cable Diameter is important

In high-density patching areas, the selected patch lead cable diameter can either increase or decrease congestion. It is generally recommended that simplex fibre optic patch leads have a diameter of approximately 2mm.

When selecting duplex singlemode fibre optic patch leads, there are a couple of options. Firstly, a figure 8 (2 x 2mm cords) patch cord is available, with each connector being physically separated (simplex connector). Secondly, the more common option for duplex fibre patch leads is a round 3mm duplex cable. This option requires the use of a uniboot duplex fibre optic connector, however, the smaller cable diameter helps reduce congestion in patching fields.

What are Active Optical Cables?

The proliferation of bandwidth-hungry applications such as 4K/8K/10K video, as well as augmented and virtual reality, are all fueling the need for reliable, faster data transmission between sources and displays. At lengths of 5 m and beyond, copper cables are simply no longer able to keep up with this insatiable bandwidth demand at the speeds required. Fiber optics is the answer.

Active Optical Cables (AOCs) convert electrical signals into optical for the transmission of video and data communications, over short or long distances, between sources and displays. Compared with direct attach copper cable for video and/or data transmission, AOCs provide many advantages, such as lighter weight, faster speeds, lower power consumption, lower interconnection loss, and increased flexibility. Because AOCs are thin and flexible, they can be routed through walls much easier than a copper cable.

AOCs are ordered by connector type and length, plus some optional features if needed. They are available in many different connector types – including HDMI, DisplayPort, USB, QSFP, and SFP. Desired length is in meters. Jacket type can also be specified: shielded, plenum, Euro market, etc.

When using AOCs, it is important to make sure that the source end of the cable is connected to the device that generates the video signal.

What is Direct Attached Cables(DAC)

Direct Attach Cables(DAC) are a form of shielded high-speed cable with SFP connectors on either end (SFP, SFP+, QSFP, QSFP+ modules). These are generally used to connect switches to routers, storage or servers within the same rack or adjacent racks. DAC cables are becoming increasingly popular, not just within data centers but within wider areas of the industry, as they offer a very cost-effective (almost half than using transceiver and fiber cables separately), efficient and easy way of making these connections.  The modules cannot be removed from the cable and so all DAC cables are a fixed length. This is one of the drawbacks of using DAC cables compared to using a combination of fiber cables and optical transceivers. Mainly there are two types of DAC cables and those are

·Direct Attached Copper Cables(DAC cables)

·Active Optical Cables(AOC cables)

Direct Attached Copper Cables (DAC cables)

DAC cables are made from Twinax copper cables and are factory terminated with modules that provide an electrical connection directly into active equipment. Since high-speed cables are sensitive to electromagnetic fields, the shielding is an important quality factor for the copper cables. This is written on the cables in the form of AWG ratings (American Wire Gauge (AWG) system which defines wire size in diameters and it’s showing the quality of shielding) like 28AWG and 30AWG. When AWG values increases it will increase the protection against electromagnetic waves. The longer the distance, the higher the AWG rating should be.

There are different types of high-speed DAC cables; direct and breakout, passive and active. A direct connect DAC cable will connect one port/line card to another (overall single cable). In fact, direct connect DAC cables are the most commonly seen in data centers. A breakout DAC cable will allow one port to be connected up to 4 other ports (DAC cable where there is a QSFP+ transceiver with 40Gbps transfer speed can be terminate into 4 x SFP+ cables where each terminal will provide 10Gbps transfer speed).

The DAC cable’s termination can be either SFP transceiver or QSFP transceivers. So depending upon the characteristics of these transceivers the DAC cables properties will also change.

Even though we have classification direct and breakout cables, the main differentiation is based on the classification Passive and Active cable structure which is a vital part in defining the cables to be used.

Passive DAC cables

The most basic version of this cable is the ‘Passive Assembly’ where the data cables are directly connected to the Transmitting and Receiving signal. Hence, it has a minimal power consumption of no more than 0.15w and generally for short reach up to 7meters. This is the most commonly used ones also due to the reason that DAC cables are used mainly for the interconnection between devices in the same rack or adjacent racks.

Active DAC cables

The active cable version contains more sophisticated electronics where the transmitting power is amplified to give a better data-pulse. You can see this in the product naming like ACU and not CU (e.g. SFP-H10GB-ACU5M vs SFP-H10GB-CU5M). An active DAC cable will offer slightly longer transmission distance than a passive DAC cable as it uses electronics within the modules at each end to boost the signals. It allows a little longer transmission distance up to 15m and ensures better transmission quality. whereas it has a higher price and consumes more power around 0.5-1w.

As a summary of DAC cables, we can say that it’s used to establish the connection between devices when the speed is at 10G we will choose SFP+ to direct DAC cables (passive or active depends on distance). When the speed rate is up to 40G we will choose QSFP+ DAC cables (passive or active depends on distance).

100G QSFP28 Optical Transceiver Comparison

Nowadays, the trend for 100G Ethernet network is bullish and inevitable. Thus, the demands for 100G modules are becoming greater and greater that account for a relatively high proportion of network construction costs. Among various 100G optical transceivers that are capable of connecting 100G traffic, the 100G QSFP28 optical transceiver is the most preferred module for smaller size and lower power consumption. What are 100G QSFP28 optical transceivers? What are the differences between them? How do we choose 100G QSFP28 optics? Today, we will make a comprehensive comparison of 100G QSFP28 optical modules for you.

What Is 100G QSFP28 Optical Transceiver?

The 100G QSFP28 optical transceiver is designed for 100 Gigabit Ethernet, EDR InfiniBand, or 32G Fibre Channel. It generally has the exact same footprint and faceplate density as 40G QSFP+. Just as the 40G QSFP+ is implemented using four 10Gbps lanes, the 100G QSFP28 module is implemented with four channels of high-speed differential signals with data rates ranging from 25Gbps up to potentially 40Gbps. With an upgrade electrical interface, the QSFP28 100G transceiver is capable of supporting signals up to 28Gbps. QSFP 100G SR4, QSFP 100G LR4, QSFP 100G PSM4, QSFP 100G CWDM4, and QSFP 100G ER4 are the five common types of 100G QSFP28 modules designed to meet the different transmission distance requirements. Compared with 100G CFP/CFP2/CFP4 transceivers, the 100G QSFP28 module surpasses them with the strong ability to increase density, decrease power consumption, and decrease the price per bit.

Differences between the 100G QSFP28 Transceiver

In this section, we will describe the differences between these 100G QSFP28 optics from the perspectives of standards, laser types, transmission media and transmission distances.

100G QSFP28 Optical Module Standards

The 100G QSFP28 optical module standards are mainly defined by two key organizations, namely IEEE and Multi Source Agreement (MSA). The QSFP28 SR4, QSFP28 LR4, QSFP28 ER4 are defined by the IEEE. How to clarify these three items from their names? The ‘QSFP’ means the form factor; ‘28’ represents that each lane has a maximum transmission rate of 28Gbps; ‘SR’ means short reach (100m), ‘LR’ is long reach (10km) and ‘ER’ is extended reach (40km). ‘4’ represents that the module has 4 lanes. For example, the QSFP28 LR4 means that it is a long reach 100G module which can transmit 100G signals over four wavelengths with a transmission distance of 10km.

100GBASE-SR4 and 100GBASE-LR4 are the most commonly used 100G interface specifications defined by the IEEE. However, the transmission distance of QSFP28 SR4 is too short to meet all interconnection requirements and the cost of QSFP28 LR4 is too high for large data centers. Therefore, MSA brought a solution for mid-range connectivity to the market and defined the standards of QSFP28 PSM4 and CWDM4. Although the capability of QSFP 100G LR4 completely covers QSFP28 CWDM4, but the QSFP 100G CWDM4 solution is much cheaper and more competitive than QSFP28 LR4 in the scenario of 2km transmission.

The VCSEL laser features with small size, low power consumption, easy integration, low price and high coupling efficiency with multimode fibers, which is often used for QSFP28 SR4 modules. The QSFP28 LR4 and QSFP28 ER4 optics are used for long-distance transmission (10km or 40km), which need lasers with advantages of large eye volume, small dispersion, large extinction and long distance. The EML is designed to meet all those requirements for QSFP 100G LR4 and QSFP 100G ER4 transceivers. The DML can realize the signal modulation through the way of modulating the injection current of the laser. Since the magnitude of the injection current changes the refractive index of the active region of the laser, causing wavelength drift to generate dispersion. Thus, it is difficult to achieve high-speed signal modulation and it can not transmit for a very long distance. Thus, the DML laser is suitable for QSFP28 PSM4 and QSFP28 CWDM4 modules with a transmission distance of 500m or 2km.

QSFP 100G Transmission Media & Transmission Distance

The 100G QSFP28 optical transceivers are equipped with LC duplex or MTP/MPO-12 connectors, which transmission distances vary from 70m to 40km. The transmission distances of the QSFP28 optics decide the application scenarios of them. All the QSFP28 100G transceivers can be applied to direct connection, interconnection in enterprises and data center networks. The following diagram shows the specific differences of the QSFP 100G optics.

How to Select the 100G QSFP28 Optical Transceiver?

After introducing the differences of the various kinds of 100G QSFP28 optical transceiver, you may have a basic understanding of them. How to choose your QSFP28 100G modules in the practical application? Here is a selection guide for you.

For transmission distance between 5m and 100m, you can choose the QSFP28 SR4 optical transceiver module, it can transmits 70m using OM3 fibers or 100m using OM4 fibers.

For transmission distance between 100m to 2km, you can choose QSFP 100G PSM4 or QSFP28 CWDM4 modules. The cost of QSFP28 CWDM4 is much higher than the QSFP28 PSM4. However, the QSFP28 CWDM4 requires only two single mode fibers in two-way transmission which is much less than the eight single mode fibers of QSFP28 PSM4, the total cost of the QSFP 100G PSM4 raises very quickly. In practical applications, it is necessary to decide whether to use QSFP28 PSM4 or QSFP28 CWDM4 depending on the interconnection distance.

For transmission distance between 10km to 40km, you can choose QSFP 100G LR4 which has a maximum transmission distance of up to 10 km or QSFP28 ER4 transceivers which transmission distance can reach up to 40km.

40G QSFP+ Module is a Great Progress for Telecom Industry

are you still worrying about your slow network speed? No, there is a high speed transceiver. 40G QSFP+ transceivers make you enjoy the better transmission communications. As an essential component to support 40G network, QSFP+ modules which allow data rates of 4×10 Gbit/s to be emerged. This article is to introduce the 40G QSFP+ modules, include 40G QSFP+ cables and 40G QSFP+ transceivers. fiber-mart.com supplies high quality QSFP+ transceivers which are used primarily for short reach applications in switches, routers, and data center equipment.

What’s 40G QSFP+ Module?

The 40G QSFP+ module is a compact, hot-pluggable transceiver used for data communications applications. It supports Serial Attached SCSI, 40G Ethernet, QDR (40G) and FDR (56G) Infiniband and other communications standards. Compared with SFP+ modules, QSFP+ transceiver increases the port-density of 3-4 times.

The 40GBASE-SR4 is based on MMF (Multi-Mode Fiber) optic cable which is cheaper than SMF (Single-Mode Fiber) optic cable. It is able to transmit light in a relatively short distance. 40G QSFP+ SR4 transmission distance is between 100m and 150m.

The 40GBASE-LR4 with a pair of SMF optic cable provides two SC fiber optic connectors for connection. 40G QSFP+LR4 transmission distance is over 10km.

What are features of 40G QSFP+ Modules?

1). Hot-pluggable input/output device that plugs into a 40 Gigabit Ethernet QSFP port

2). High-speed electrical interface compliant to the IEEE 802.3ba standard

3). Certified and tested on QSFP 40G ports for superior performance, quality, and reliability

4). Digital Diagnostics Monitoring Interface

Besides its high-density applications, QSFP+ modules provide 40Gb/s Ethernet data rates over MMF (Multi-Mode Fiber) optic cable and SMF (Single-Mode Fiber) optic cable. QSFP+modules take up very little space on a switch or server interface, allowing vendors to provide multiple QSFP+ ports in the same space.

How about the 40G QSFP+ modules’ Market?

With the increasing demands of global Internet traffic, higher requirements are concentrated on the network communications transmission capacity. The market research shows that the whole communication network is in urgent need of the optical transmission bandwidth upgrade from the original 10G to 40G and 100G. Data Center Construction requires the higher bandwidth and port-density for modules. Therefore, 40G QSFP+ modules have a huge overseas sales market, such as Facebook, Google, Cisco and so on. It means that QSFP+ transceiver modules have a good future.

Cisco 10G Ethernet SFP Modules

It is well known that Cisco is a worldwide leader in the telecommunication industry. Cisco products and services are very welcome among the users, which ranges from application networking services, optical networking, to routers, switches, interfaces and modules, etc. This paper will introduce Cisco 10 Gigabit Ethernet SFP modules.

10 Gigabit Ethernet (10GE, 10Gbe, or 10 GigE) is a group of computer networking technologies for transmitting Ethernet frames at a rate of 10 gigabits per second (10 billion bits per second). It was first defined by the IEEE 802.3ae-2002 standard. Below is part of the 10 Gigabit Ethernet standards related to this topic.

According to the standards, Cisco SFP modules for 10 Gigabit Ethernet have different types, such as Cisco SFP-10G-LRM module, Cisco SFP-10G-ER module, Cisco SFP-10G-ZR module, Cisco SFP-10G-SR module and Cisco SFP-10G-LR module, etc. Below will introduce two most common Cisco SFPs: Cisco SFP-10G-SR and Cisco SFP-10G-LR.

Cisco SFP-10G-SR

The Cisco SFP-10G-SR, compatible with 10GBASE-SR standard, supports a link length of 26m on standard Fiber Distributed Data Interface (FDDI)-grade multimode fiber (MMF). Using 2000MHz km MMF (OM3), it is possible to support link lengths up to 300m. While using 4700MHz km MMF (OM4), the link lengths could be up to 400m. Cisco 10GBASE-SR SFP module has 850nm lasers and uses LC duplex connector. The transmit and receive wavelength could range from 840nm to 860nm. The bail latch color of SFP-10G-SR is beige and it can support commercial temperature range (COM): 0 to 70°C (32 to 158°F). Below is a picture of Cisco SFP-10G-SR.

Cisco SFP-10G-LR

The Cisco SFP-10G-LR is compliant with 10GBASE-LR standard and supports a link length of 10 kilometers on standard single-mode fiber (SMF). Cisco 10GBASE-LR SFP module uses 1310nm lasers and supports LC duplex connector. The transmit and receive wavelength of Cisco 10G LR transceiver module could range from 1260nm to 1355nm. And the bail latch color of SFP-10G-LR is blue. Also, its operating temperature range is 0 to 70°C (32 to 158°F). Below is a picture of Cisco SFP-10G-LR.

As stated above, Cisco SFP-10G-SR and Cisco SFP-10G-LR have their own features and can be applied in 10 Gigabit Ethernet. If you are looking for Cisco 10GBASE SFP modules, Fiber-mart.com can meet your demands. Fiber-mart.com has high-quality and low-price Cisco SFP such as SFP-10G-SR, SFP-10G-LR, SFP-10G-ER, SFP-10G-LRM and so on. It is an excellent option for you.