Fiber Optic Transceiver Archives - Page 7 of 10

Choose the Right Patch Cable for Your Transceiver Module

To a large extent, a fluent data transmission relies on the seamless transition between patch cables and fiber optic transceivers. As high bandwidth gradually dominates the market, patch cables and transceivers become much more essential to data transmission, especially for data transmission between the switches and equipment. But when you try to find the right patch cable for your transceiver, you may feel dazzling about the great variety of products. Don’t worry, this article will help you find the quickest way to choose the suitable product. But first, let’s have a look at the basic knowledge about patch cables and transceiver modules.

Overview of Patch Cables and Transceiver Modules

A patch cable or patch cord is an electrical or optical cable used to connect one electronic or optical device to another for signal routing. It is composed of an electrical or optic cable terminated with connectors on the ends. Optical patch cables are now widely used in data centers for data transmission. They have different fiber connectors including LC, SC, ST, FC, MTRJ, E2000, MU, MPO/MTP, etc. As for fiber types, there are also single-mode patch cables and multimode patch cables. Single-mode patch cables can further be classified into OS1 and OS2. While the multimode can be further divided into OM1, OM2, OM3 and OM4.

fiber-vs.-copper

Transceiver is a self-contained component that can both transmit and receive. It is often inserted in devices such as switches, routers or network interface cards which provide one or more transceiver module slot. Many transceivers types, such as SFP, X2, XENPAK, XFP, SFP+, QSFP+, CFP, etc. are used for various applications. The transceiver accepts digital signals from the Ethernet device and converts them to optical signals for transmission over the fiber.

Several Aspects to Consider

Transmission Media

Two kinds of transmission media can be found in the network. They are optic fiber cable and copper cable. Therefore, transceivers also have two types based on transmission media — copper based transceivers and fiber optic based transceivers. Copper based transceivers like 100BASE-T SFP, 1000BASE-T SFP are the commonly used types. They have a RJ45 interface to connect with the copper cables. Generally, cat 5, cat 6 and cat 7 cables attached with RJ45 connectors are typically linked to the copper based transceivers.

Compared with copper based transceivers, fiber optic transceivers support higher data rates for over 100 Gbps. The supported fiber patch cables are more complicated for selection. Usually single-mode and multimode fiber patch cables are used. But according to different transmission rates and transmission distance, further choices should be made.

Transmission Rate and Distance

It is known that data rate decreases as the transmission distance increases in fiber optic cables. Multimode fiber optic cables are often used for short distances due to the high cost of single-mode optical cables. But single-mode patch cables have better performance for different data rates in both long and short distances. Thus, if your transceiver supports high data rate over long distance, single-mode should be a better choice, and vice versa.

Transceiver Interface

Interfaces are also important to the selection of patch cables that match with transceivers. Optical transceivers usually use one port for transmitting and one port for receiving. Cables with duplex SC or LC connectors are typically employed to connect with this type of fiber optic transceivers. However, for BiDi transceivers only one port is used for both transmitting and receiving. Thus, simplex patch cables are used with BiDi transceivers.

Other high data rate transceivers like 40G/100GBASE QSFP+ often use MTP/MPO interfaces. They should be connected to the network with multi-fiber patch cords attached with MTP/MPO connectors. If these ports are used for 40 G to 10 G or 100 G to 10 G connections, fanout patch cables should be used.

transceiver-and-patch-cords

Conclusion

Knowing the transmission media, transmission data rate and distance, transceiver interfaces can give you a general direction of which type of patch cables should be chosen. Only matched patch cables and transceiver modules can provide better performance.

100G Optical Transceiver Solutions

Network has been rapidly developed over the years. People are always dreaming of entering into the world of higher bandwidth. And now the dream has come true since we already reach the 100 gigabit Ethernet (100 GbE) networking. This technology enables the transmission at rates of 100 gigabits per second (100 Gbit/s). The standard was first defined by the IEEE 802.3ba in 2010. To accommodate the trend, different types of 100G optical transceiver emerge as a reflection of the development. QSFP28 (quad small form-factor pluggable 28), CFP (centum form-factor pluggable) and CXP (centum extended-capability form-factor pluggable) are most commonly used optical transceiver solutions for 100G active equipment. Today, the article will mainly introduce these three solutions.

100G Optical Transceiver Solutions

CFP

Specified by a multi-source agreement (MSA) between competing manufacturers, CFP was designed to replace many former transceivers like SFP+, SFP, XFP with a significantly larger support of 100 Gbps. The electrical connection of a CFP uses 10 x 10Gbps lanes in each direction (RX, TX). The optical connection can support both 10 x 10Gbps and 4 x 25Gbps variants. In addition, there are another two CFP next-generation 100G form factors — CFP2 and CFP4. Compared to the existing CFP, CFP2 and CFP4 are respectively double and quadruple front panel port density. All of them are now available on the market.

CFP

QSFP28

QSFP28 transceiver is designed for 100G Ethernet which uses the 4 x 25 wiring specification. It has the same size as 40G QSFP+ but with a higher performance. The 100G QSFP28 is implemented with four 25Gbps lanes. “28” stands for the highest possible rate of 4x28Gbps in transmission. Two basic versions of QSFP28 transceivers are 100GBASE-SR4 QSFP28 transceiver and 100GBASE-LR4 QSFP28 transceiver, which are respectively used for multimode fiber (MMF) and single-mode fiber (SMF) 100G applications. 100GBASE-SR4 QSFP28 operates at multimode fiber for a distance of 100 m. 100GBASE-LR4 QSFP28 can support a much longer distance of 10 km.

CXP

As a complement to CFP, CXP is also specified by MSA aiming at the clustering and high-speed computing markets. CXP has a higher density network interface with 45 mm in length and 27 mm in width, making it slightly larger than an XFP or 1/4 size of a CFP transceiver. It has a form-factor pluggable active device interface with 12 transmit and 12 receive lanes, capable of supporting bit-rates in excess of 10 Gbps per lane on a variety of optical transmission technologies.

cxp

Future Trend of Optical Transceivers in Data Centers

In the future, higher bit rates over 100G are the inevitable trend in data centers. The next data center developments will be following the 4x trend set by 40G and 100G, such as 200G, 400G, etc. Accordingly, optical transceivers should keep up with the steps and satisfy higher demands.

In 200G applications, next generation switching ASICs (Application Specific Integrated Circuits) are expected to have native port speeds of 50G and 128 ports, which correspond to a net throughput of 6.4 Tbps. This means that 200G QSFP modules (QSFP56, 4 x 50 Gbps) would result in a front panel bandwidth of 6.4 Tbps (32 x 200 Gbps).

For 400G applications, the module must accommodate either 16 x 25G or 8 x 50G electrical input lanes, which exceeds the 4 lanes defined for the QSFP. 400G transceivers will have larger size than QSFP. However, meeting the 3.5W power limit of QSFP modules appears infeasible for some 400G implementations. Thus, proposals for larger form factors for 400G can be anticipated from CFP MSA, which has had large success in 100G with CFP, CFP2, and CFP4. In this case, a key requirement will be that the size allows for at least 16 ports on the front panel in order to satisfy a net throughput of 6.4 Tbps (16 x 400 Gbps, and possibly more).

Conclusion

The market of 100G optical transceivers is accelerating. It is no doubt that more 100G transceivers and other assemblies will be deployed in data centers. QSFP28, CFP series and CXP are presently the most suitable solutions for 100G applications. Definitely one of them can solve your project needs.

QSFP+ Transceiver for High-Density 40GE Connectivity

With the development of the SFF-8436 Multi Source Agreement, many vendor are now offering a variety of IEEE- and MSA-compliant Quad Small Form-Factor Pluggable Plus (QSFP+) devices for fiber networks. And there are basic three 40G QSFP+ optics for this standard: 40G LR4 QSFP+ transceiver, 40G SR4 QSFP+ transceiver and 40G LR4 parallel single mode (PSM) transceiver. This article will take a close look at these 40G QSFP+ optics for high-density 40 GE connectivity.

40G LR4 QSFP+ Transceiver

Conforming to the 802.3ba (40GBASE-LR4) standard, the 40G LR4 QSFP+ transceiver together with the LC connector can support an optical link length up to 10 kilometers over single mode fiber. For example, the following Juniper JNP-QSFP-40G-LR4 compatible 40GBASE-LR4 QSFP+ transceiver offers 4 independent transmit and receive channels, supporting link distance of 10 km over single mode fiber. In the process of transmitting, this kind of transceiver has to introduce MUX/DEMUX to multiplex/de-multiplex optical signals.

JNP-QSFP-40G-LR4

The working principle of this kind of QSFP+ transceiver is : in the transmit side, four 10 Gbp/s serial data streams are passed to laser drivers. The laser drivers control directly modulated lasers (DMLs) with wavelengths. the output of the four DMLs are optically multiplexed to a single-mode fiber through an industry-standard LC connector. In the receive side, the four 10 Gbp/s optical data streams are optically de-multiplexed by the integrated optical demultiplexer; then, each data steam is recovered by a PIN photodetector/transimpedance amplifier and passed to an output driver.

40G SR4 QSFP+ Transceiver

The 40G SR4 QSFP+ transceiver, conforming to the 802.3ba (40GBASE-SR4) standard, provides a 40G optical connection using MPO/MTP fiber ribbon connectors. Unlike the 40G LR4 QSFP+ transceiver, this kind of transceiver are used together with multi-mode fiber, supporting with a link length up to 100 meters on OM3 cable and 150 meters on OM4 cable.

The operating principle of the 40G SR4 QSFP+ Transceiver is : the transmitter convertsparallel electrical input signals into parallel optical signals through the use of a laser array. Then the parallel optical signals are transmitted parallelly through the multi-mode fiber ribbon. Reversely, the receiver converts parallel optical input signals via a photo detector array into parallel electrical output signals.

40G LR4 Parallel Single Mode (PSM) Transceiver

40G PSM transceivers are used to provide support for up to four 10Gb Ethernet connections on a QSFP+ port over single mode fiber. These transceivers support distance of up to 10 kilometers over single mode fiber using an 8 parallel fiber MPO interface. Each fiber pair can be broken out to a 10Gb Ethernet connection, compatible with up to four 10GBASE-LR interfaces. The MPO to 4 x LC single mode fiber patch cord can be used to breakout the 4 fiber pair of the MPO parallel connector to 4 separate fiber pairs.

Summary

To sum up, 40G SR4 QSFP+ transceivers are suitable for short-distance transmissions. So they are often used in data centers to interconnect two Ethernet switches with 12 lane ribbon OM3/OM4 cables. while 40G LR4 QSFP+ transceivers and 40G LR4 PSM transceivers are often used in long-distance transmission applications. Fiberstore offers a wide range of 40G QSFP+ transceivers, like 40GBASE-SR4, 40GBASE-LR4, 40GBASE-CR4 QSFP+ transceivers, etc. Besides, we also provide 40G direct attach cables, such as Juniper QFX-QSFP-DAC-1M, Cisco QSFP-4X10G-AOC3M and so on.

Guide to 40GBASE-SR4 QSFP+ Transceivers

Today’s enterprise data centers and networking environments are undergoing an infrastructure transformation, requiring higher speeds, greater scalability, and higher levels of performance and reliability to better meet the demands of business. As speed and performance needs increase, the 40GBASE-SR4 QSFP+ optical transceivers have become an integral part of overall system design. This article will give you a comprehensive introduction to 40GBASE-SR4 QSFP+ optical transceivers.

What Is 40GBASE-SR4 QSFP + Transceiver

40GBASE-SR4 is a fiber optic interface for multimode fiber of OM classes 3 and 4 with four parallel OM3 or OM4 fibers in both directions. “S” means short, indicating that it is an interface for short distances. The “R” denotes the type of interface with 64B/66B encoding and the numeral 4 indicates that the transmission is carried out over a ribbon fiber with four multimode fibers in every direction. Each lane has a 10 Gbit/s data rate. The 40GBASE-SR4 QSFP+ transceivers are hot-swappable, low-voltage digital diagnostic Ethernet optical transceivers that support high-speed serial links over multi-mode optical fiber at a signaling rate of 4×10 Gbps. They comply with QSFP+ mechanical, optical, and electrical specifications (SFF-8436). 40GBASE-SR4 QSFP+ modules usually use a parallel multimode fiber (MMF) link to achieve 40G. It offers 4 independent transmit and receive channels, each capable of 10G operation for an aggregate data rate of 40G over 100 meters of OM3 MMF or 150 meters of OM4 MMF. It primarily enables high-bandwidth 40G optical links over 12-fiber parallel fiber terminated with MPO/MTP multifiber female connectors.

Applications of 40GBASE-SR4 QSFP + Transceiver

40GBASE-SR transceivers are used in data centers to interconnect two Ethernet switches with 8 fiber parallel multimode fiber OM3/OM4 cables. The QSFP+ transceiver modules can be connected to both copper and optical cables. In the process of transmitting data, the 40GBASE-SR4 QSFP+ transceiver converts parallel electrical input signals into parallel optical signals by a 850nm vertical cavity surface emitting laser (VCSEL) array. All data signals are differential and the data rate can be up to 10 Gbps per channel. For example, Extreme 10319 compatible 40GBASE-SR4 QSFP+ transceiver from Fiberstore operates in 4-lanes at a wavelength of 850nm.

QSFP-40G-SR4 vs. QSFP-40G-CSR4

40GBASE-CSR4 QSFP modules extend the reach of the IEEE 40GBASE-SR4 interface to 300 and 400 meters on laser-optimized OM3 and OM4 multimode parallel fiber, respectively. Each 10-gigabit lane of this module is compliant to IEEE 10GBASE-SR specifications. This module can be used for native 40G optical links over 12-fiber parallel cables with MPO/MTP female connectors or in a 4x10G mode with parallel to duplex fiber breakout cables for connectivity to four 10GBASE-SR interfaces. Cisco compatible QSFP-40G-CSR4 transceiver from Fiberstore is optimized to guarantee interoperability over the complete specification range of 10GBASE-SR.

Fiberstore offers a wide range options of brand-compatible 40GBASE-SR4 QSFP+ transceivers. In order to ensure each transceiver with high-compatibility, we have a comprehensive and reliable test assured program for each optics. All these 40GBASE-SR4 QSFP+ transceivers will be tested in the original-brand switches to guarantees the high compatibility.

What’s SFP and SFP+ MSA? Why is SFP/SFP+ MSA important?

A small form-factor pluggable (SFP) is a type of transceiver device that has been standardized by the MSA (multi-source agreement). The MSA will define the characteristics of the system and is typically an agreement between multiple manufacturers. The agreements guarantee that any SFP or SFP+ device from any vendor will function properly. This article will give you a more comprehensive introduction to the SFP MSA and SFP+ MSA.

An Overview of Pluggable Optical Transceiver MSA Standards

Both SFP and SFP+ optical transceivers are standardized by MSA. These documents strictly define sufficient characteristics of an optical transceiver so that system (like Ethernet switch, Router, and media converter) vendors may implement ports on their devices, therefore, MSA compliant pluggable optical transceivers (SFP or SFP+) from any vendor will function properly.

Pluggable optical transceivers are physically composed of a small printed circuit board (PCB) containing electronic circuity, with an electrical PCB “edge connector” at one end and, typically, a fiber optic connector (dual LC-type in the case of SFP/SFP+ modules) at the other, packaged in a metal housing including a release latch. The basic function of the device is to convert electrical transmit data from the host into an optical signal transmitted onto a connected fiber optic cable, and, in the other direction, convert a received optical signal into an electrical one to be sent to the host system over the edge connector.

What is Defined by the SFP MSA or SFP+ MSA?

The main elements defined in the SFP/SFP+ MSA is listed as follows:

Mechanical Interface

Mechanical dimensions of the device (H: 8.5mm, W: 13.4mm, D: 56.5mm)
Transceiver edge connector to host PCB-mounted electrical connector mating
Host board mechanical layout (location/size of solder pads, etc.)
Insertion, Extraction and Retention forces
Labeling
Bezel design considerations for host systems
Electrical connector mechanical aspects
Cage assembly dimensions (hollow cage mounted in host system)

Electrical Interface

Pin definitions
Timing requirements and Status I/O
Module definition interface and data field description

Besides, the Digital Diagnostics Monitoring (DDM) feature common in many modern SFP/SFP+ transceivers as defined in SFF-8472 MSA specification. “D” in GLC-LH-SMD represents the DDM function according to the industry standard MSA SFF-8472. The SFF-8472 added DDM interface and outlined that DDM interface is an extension of the serial ID interface defined in GBIC specification, as well as the SFP MSA.

The Importance of SFP/SFP+ MSA

MSAs, like most standards efforts, are important primarily because they can give customers a choice in suppliers from which they purchase products. Freedom of choice is the foundation of the efficient operation of markets. Customers in the marketplace should have the benefit of multiple independent suppliers, each competing to gain a share of the market. This behavior forces suppliers to be as efficient and creative as possible, driving down costs and offering customers the widest array of options.

It is true that some system vendors have attempted to subvert the standardizing value of the SFP MSA or SFP+ MSA. The most common scheme is to write a unique code into some of the undefined memory in the EEPROM of each SFP/SFP+. When the transceiver is inserted into the host switch, its EEPROM is read, and, if the code is “incorrect” the module is rejected as “incompatible”. But Fiberstore can do it. At present, FS.COM offers a comprehensive brand’s compatible solution of the transceivers which can meet the demands for Cisco, HP, Juniper, NETGEAR, Brocade etc.