Monthly Archives: November 2014

Optical Transceivers for FIs

Understanding FIs

A FI is the core component of a UCS solution. FIs are typically configured as highly available clustered pairs in production environments. It’s possible to run a single FI-based design as a proof of concept test deployment before actually implementing it in production. FIs provide the following two capabilities:

  1. Network connectivity to both LAN and SAN
  2. UCS infrastructure management through the embedded management software, UCSM, for both hardware and software management

FIs are available in two generations, namely Cisco UCS 6100 series and Cisco UCS 6200 series. The core functionality is the same in both generations; however, UCS 6200 series has a newer generation Application Specific Integrated Circuit (ASIC), higher throughput, and increased number of physical ports. Both generations can be upgraded to the latest UCSM software.

FIs provide converged ports. Depending on the physical Small Form Factor Pluggable (SFP) transceivers and FI software configuration, each port can be configured in different ways. Cisco 200 series FI ports can be configured as Ethernet ports, Fibre Channel over Ethernet (FCoE) ports, or Fibre Channel (FC) ports. On the other hand, 6100 series converged ports only support Ethernet and FCoE (they also support FC, but only in the expansion slot).

Cisco 6200 Series switches

In production, FIs are deployed in clustered pairs to provide high availability. Cisco-supported implementation requires that clustered FIs be identical. The only possibility for having different FIs in a cluster is during a cluster upgrade.

Exploring Connectivity Transceivers for FIs

A variety of SFP transceivers are available for The Cisco UCS 6200 series. These transceivers provide south-bound IOM connectivity and north-bound network and storage connectivity. They are based on industry-standard SFP+ specifications.

Transceivers can be selected depending on the technology, for example, Ethernet or FC, and also according to the distance requirements. For shorter distances between FIs, IOMs, and north-bound network switches, twinax cables with integrated SFP is an economical alternative as compared to fibre optic SFP.

The most commonly used transceivers include following:

  • Cisco SFP-10G-SR: This is a multimode optical fibre 10Gbps Ethernet SFP that can be used for distances up to 400 meters.
  • Cisco SFP-10G-LR: This is a single-mode optical fibre 10Gbps Ethernet SFP that can be used for distances up to 10 Km.
  • Cisco SFP-10G-TET: This is a low power consuming multimode fibre optic 10Gbps Ethernet SFP that can be used for distances up to 100 meters.
  • Cisco SFP-H10GB-CuxM: These are the twinax cables providing low cost 10Gbps Ethernet connectivity and are available in 1, 3, 5, 7 and 10 meter configurations.
  • Cisco SFP-H10GB-ACU10M: This is a 10-meter-long twinax cable providing 10Gbps Ethernet. At a length of 10 meters, this cable requires active transceivers at both ends.
  • Cisco GLC-T: 1000BASE-T SFP or SFP-compatible ports only,these are based on the SFP Multi Source Agreement (MSA) and compact RJ-45 connector assembly. For SFP-compatible ports only.
  • Cisco GLC-SX-MMD: These modules supporting dual data-rate of 1.25Gbps/1.0625Gbps and 550m transmission distance with MMF, for SFP-compatible ports only.
  • Cisco GLC-LH-SMD: These modules supporting dual data-rate of 1.25Gbps/1.0625Gbps and 10km transmission distance with SMF, for SFP-compatible ports only.
  • DS-SFP-FCxG-xW: These are multi-mode and single-mode fibre optic FC transceivers that are available at 2, 4, and 8Gbps transfer speeds.

1000Base-SX SFP Transceiver

Where to buy These Optical Transceivers

Fiberstore provide a full range of optical transceivers, such as SFP+ (SFP Plus) transceiver, X2 transceiver, XENPAK transceiver, XFP transceiver, SFP (Mini GBIC) transceiver, GBIC transceiver, CWDM/DWDM transceiver, 40G QSFP+ & CFP, 3G-SDI video SFP, WDM Bi-Directional transceiver and PON transceiver. All our fibre transceivers are 100% compatible with major brands like Cisco, HP, Juniper, Nortel, Force10, D-link, 3Com. They are backed by a lifetime warranty, and you can buy with confidence. We also can customise optical transceivers to fit your specific requirements.

Where to Buy 3 Port Optical Circulator

Three port Optical Circulator allows light to move in only one direction. A signal entering to Port 1 will exit Port 2 with minimal loss, while a signal entering Port 2 will exit Port 3 with minimal loss. Light entering port 2 experiences a large amount of loss at port 1, and light entering port 3 experiences a large amount of loss at ports 2 and 1. Optical Circulators are non-reciprocal devices. Which means that any changes in the properties of the light caused by passing through the device are not reversed by traveling in the opposite direction.

Due to its high isolation and low insertion loss, optical Circulators are commonly used in advanced communication systems as add-drop multiplexers, bi-directional pumps, and chromatic dispersion compensation devices.

3 port optical circulator

Figure 1. Circulator used to drop an optical channel from a DWDM system using a Fibre Bragg Grating.

As the Figure 1 shows: The input DWDM channels are coupled into Port 1 of the device with a FBG device connected to Port 2. The single wavelength reflected from the FBG then reenters the Circulator in Port 2 and is routed accordingly to Port 3. The rest of the signals move through the FBG and exit on

optical circulator

Figure 2. Circulator can often send optical signals through a single fibre in 2 directions.

Circulators could also be used to deliver optical signal in 2 directions down a single fibre. As the picture shows: A Circulator is located at each side of the fibre. Each Circulator functions to add a signal in one direction while removing the signal in the other. View the example in the Figure 2.

A standard Circulator operating in a 1550nm wavelength window usually has insertion loss of about 0.8dB, which is slightly higher than an isolator because of its more complex optical structure. The isolation value is on the order of -40dB and the directionality is often better than -50dB.

Characteristics

  • Low Back Reflection
  • High Extinction Ratio
  • Low Insertion Loss
  • High Return Loss

Applications

  • DWDM system
  • Add-Drop Multiplexing
  • Fibre Amplifier
  • Fibre Sensor
  • Chromatic Dispersion Compensation Devices
  • Fibre Bragg Grating

Optical Circulators can be used to achieve bi-directional optical signal transmission over a single fibre. Optical Circulators is widely used in WDM networks, polarization mode dispersion, chromatic dispersion compensation, optical add-drop modules (OADM), optical amplifiers, OTDR and fibre sensing applications. FS offer 3/4 Ports Polarization-Insensitive optical Circulator and 1310/1550/1064 Polarization-Maintaining (PM) optic Circulators. Our fibr opetical Circulators can provide high isolation, very low insertion loss, low polarization dependent loss (PDL), low polarization mode dispersion (PMD), and excellent environmental stability. Any other wavelengths, without or with any connector can customize according to your requirement.

Note:

1. Wavelength: FS can customize any other wavelengths according to your requirement.

2. Length: The default length for the cable is 1M. FS could also provide 0.5M,0.8M,1.5M, 2.0M, etc.

3. Connector: Each port of the Circulator could be with any connector such as FC/LC/SC/ST, etc.

Please contact us by email to sales@fs.com or call at +1-253-277-3058 if you have any requirement for it. For more information, please visit fs.com.

Optical Circulator Configurations and Advantages

An optical circulator is a generalized isolator having three or more ports. While an isolator causes loss in the isolation direction, a circulator collects the light and directs it to a non-reciprocal output port.

circulator connections

The figure drawn above shows the severa l possible circulator configurations.

Figure (a) illustrates the port mapping for a four-port circulator. The ports cyclically map 1 -> 2 -> 3 -> 4 -> 1. This is called a strict-sense circulator because every input port has a specific non- reciprocal output port. Construction of a strict-sense circulator with more ports becomes inelegant but ones with three ports becomes simple.

Figure (b) illustrates a non-strict-sense circulator having any number of ports greater than two. In this case each input port has a specific non-reciprocal output port except for the last port; the light input to the last port is lost. The ladder diagram reflects the optical path within the component and indicates the disconnect between the first and the last ports.

Figure (c) illustrates the three-port non-strict-sense circulator. This circulator has significance in telecommunication applications because return of light from port 3 to port 1 is not often required. For instance, the reflected light from a fibre Bragg grating need only be separated from the input light without loss, but as optical links are not typically operated in reverse there is no need for strict-sense behaviour.

An optical circulator allows the routing of light from one fibre to another based upon the direction of the light propagation. Nonreciprocal optical devices, such as optical isolators and optical circulators, are essential components of optical communication systems. Optical isolators pass light propagating in a forward direction while inhibiting the propagation of light in a backward direction. Since the optical circulator is an inherently non-reciprocal device, the light never goes to other ports. Optical circulators have wide applications. They are used to convert an existing unidirectional fibre optic communication link to a full duplex communication link by installing an optical circulator at each end of the link. Optical circulators are also used in fibre amplification systems, wavelength division multiplex (WDM) networks, optical time-domain reflectometers (OTDRs) and for test instruments.

Optical Circulator

Advantages

Although the optical sophistication of circulators makes them comparatively expensive, designers will appreciate the reliability and elegance imparted by fewer components. The resultant performance improvement may eliminate the need for more powerful transmitters, more sensitive receivers, and intermediate amplifiers, thus making optical circulators an economically interesting proposition. And, as with all technology, we can anticipate sharply lower prices as the optical circulator gains wider acceptance.

As one examines optical circulator applications, the notion of integrating the circulator, transmitter, and receiver into a single housing becomes very attractive. All elements would be aligned on a common platform, thus avoiding a multitude of external connectors and splices.

Where to Buy

Optical circulators is widely used in WDM networks, polarization mode dispersion, chromatic dispersion compensation, optical add-drop modules (OADM), optical amplifiers, OTDR and fibre sensing applications. Fiberstore offer 3/4 Ports Polarization-Insensitive optical circulator and 1310/1550/1064 Polarization-Maintaining (PM) optic circulators. Our fibre optical circulators can provide high isolation, very low insertion loss, low polarization dependent loss (PDL), low polarization mode dispersion (PMD), and excellent environmental stability.  Any other wavelengths, without or with any connector can customised according to your requirement. Fiberstore also provide Cisco Optical Transceivers, such as Cisco GLC-SX-MMD, Cisco GLC-LH-SMD and Cisco GLC-T 1000base-T, etc.

Cisco GLC-T Copper SFP Manufacturer

SFP (small form factor pluggable) is designed to convert serial electric signals into serial optical signals. SFP module is commonly inserted on a network switch so that you can connect a fibre optic system with an Ethernet system. The most popular applications where SFP modules are used include Fibre Channel and Gigabit Ethernet. Industry specifications for the SFP transceiver have been standardized by an agreement which is called the MSA (Multi Source Agreement) between competing manufacturers. The MSA guarantees inter-compatibility between vendor products. And today we’ll discuss GLC-T copper SFP modules.

Cisco GLC-T SFP

As the growth of the network, it will be essential to maintain both configuration flexibility and high port utilization for equipment deployed at the intersection of legacy copper and newly installed optical networks. Copper small form factor pluggable (SFP) module ensures the SFP form factor has emerged as the right way to optimize port-level flexibility. The maturation of GLC-T copper SFP module is playing a critical role in enabling system designers to meet these objectives while simplifying their inventory and reducing operating costs.

SFP transceivers can be acquired with a selection of receiver and transmitter types. Users can select the appropriate SFP transceiver for each fibre optic link they’re deploying to supply the specified reach according to the kind of optical fibre they’re using (i.e Multi Mode or Single Mode Fibre). GLC-T copper SFP transceiver is the small form pluggable transceiver modules which use a copper line for linking, and contains transmit and receive two decision points. Radiating portion consists of laser circuit and optical maser, receiving part consists of PIN, TIA and Limtiting Amp. Completion of the digital signal transparent O / E, the E / O conversion functions. Copper transceiver can be subdivided into copper SFP modules and copper GBIC modules.

Cisco offers various kinds of SFP transceiver modules that are suitable for many different Ethernet networking applications. 1000BASE-T SFP is designed on the SFP Multi Source Agreement (MSA). It is compliant with the Gigabit Ethernet and 1000BASE-T standards as specified in IEEE STD 802.3 and 802.3ab.

Cisco 1000BASE-T SFP for copper networks, such as the GLC-T and SFP-GE-T, operates on standard Category 5 unshielded twisted pair copper cabling of up to 100m (328 ft) link length. Cisco 1000BASE-T SFP modules support 10/100/1000 auto negotiation and Auto MDI/MDIX.

Cisco GLC-T  module provide 1Gbps bandwidth and it provides full-duplex Gigabit Ethernet connectivity to high-end workstations and between wiring closets over existing copper network infrastructure. The GLC T SFP Transceiver offers a standard serial ID information compliant with the SFP MSA. That could be accessed with the address of A0h via the 2wire serial CMOS EEPROM protocol.

In China, there are numerous SFP transceiver manufacturers, and Fibersore is the largest, which provides Cisco glc-t copper transceivers with high performance and competitive price. Fiberstore Also provides various kinds of SFP transceivers including 100M & 1G SFP, SONET/SDH SFP, 4G SFP, CWDM & DWDM SFP, BIDI SFP and Copper & SGMII SFP. SFP with special parameters can be also customized up to customers’ requirements.

Related Article: A Quick Overview of Cisco 1000BASE-T GLC-T SFP Copper Module

1000BASE-SX SFP Modules Provided by Fiberstore

Introduction of Gigabit Ethernet

Gigabit Ethernet uses the same 802.3 frame format as 10Mbps and 100Mbps Ethernet systems. This runs at ten times the clock speed of Fast Ethernet, backward compatibility is assured with earlier versions, increasing its attractiveness by offering a high bandwidth connectivity system to the Ethernet family of devices.

Gigabit Ethernet is defined by the IEEE 802.3z standard. This defines the gigabit Ethernet media access control (MAC) layer functionality as well as three different physical layers: 1000Base-LX and 1000Base-SX using fibre and 1000Base-CX using copper. These physical layers were originally developed by IBM for the ANSI Fibre Channel systems and used 8B/10B encoding to reduce the bandwidth required to send high-speed signals. The IEEE merged the fibre channel to the Ethernet MAC using a gigabit media independent interface (GMII), which defines an electrical interface, enabling existing fibre channel PHY chips to be used and enabling future physical layers to be easily added.

1000Base-SX for Horizontal Fibre

1000Base-SX, also known as 1000Base-SX, is a physical layer specification for Gigabit Ethernet over fibre optic cabling as defined in IEEE 802.3z. SX stands for short wavelength. And 1000Base-SX uses short wavelength laser (850nm) over multimode fibre as opposed to 1000Base-LX, which uses long wavelength laser over both multimode and single-mode fibre. The maximum distance of (multimode) fibre, based on 1000Base SX is 550m.

This gigabit Ethernet version was developed for the short backbone connections of the horizontal network wiring. The SX systems operate full-duplex with multimode fibre only, using the cheaper 850nm wavelength laser diodes. The maximum distance supported varies between 200 and 550 meters depending on the bandwidth and attenuation of the fibre optic cable used. The standard 1000Base-SX NICs available today are full-duplex and incorporate LC fibre connectors.

1000Base-SX SFP Transceiver

1000BASE-SX SFP Optical Module Selection Raiders

SFP module is a hot-swappable input/output device that plugs into a Gigabit Ethernet port/slot, linking the port with the fibre-optic network. SFPs can be used and interchanged on a wide variety of Cisco products and can be intermixed in combinations of IEEE 802.3z compliant 1000BaseSX interfaces on a port-by-port basis.

1000BASE-SX SFP supports link length of up to 550m (depending on fibre type) on multimode fibre at 1Gbps. This optic works at 850nm wavelength and uses a LC connector.

If you want to purchase cheaper compatible 1000Base-SX SFP modules online, Fiberstore may be the better choice. Fiberstore is the largest fibre optics manufacturer of China, which offers various of SFP modules. And you will find third-party optical modules provided by fiberstore, like HP J4858b, J4858C, Jd118b and Netgear agm731f also Cisco GLC-SX-MM, etc.

Compatible SFP transceiver modules offered by Fiberstore are third-party and fully compatible with major brands (Cisco, HP, NETGEAR, Juniper, etc.) and supported by a Lifetime Warranty. Besides the compatible SFP, we can also customize SFP transceiver modules to fit customers’ specific requirements. Contact us by live chat or mails if you could not find the exact items you need.

New product launching in Fiberstore: 24 Fibers Optical Splice Tray for FHD Fiber Enclosure – FS

What is Forcing Cisco Switches Using a Third Party

If you use Cisco switches, you’ll know that their hardware is very expensive on the market. Most of the time, this makes sense, however, it still makes Cisco users trying to find a way to reduce their cost on hardware.

One of the most saving ways is that use a third-party optical transceivers. SFP transceivers are developed to ensure that a single Cisco switch can accept a variety of standard plugs, especially for those SFP on the market with various optical formats. Usually, they’re even plug-and-play, without having to reboot.

When adding new Cisco routers, these may be an available method of saving money.

However, cisco would rather you spend $200 for their own branded SFP transceivers, rather than spend 10% of that for a third-party SFP.

In the rather harsh way, Cisco has even started setting up their Cisco Catalyst line of switches, attempting to completely shut down a port with a non-Cisco SFP in it.

The good thing is that a couple simple console commands to remove this restriction, so that can make it possible to use a reliable third-party SFP transceiver in Cisco hardware running IOS 12.2(25) SE or later.

Fiberstore SFP Transceiver

Two Commands Which Allow Third-Party SFPs On Cisco Switches

The first command is so well-hidden that it is absolutely undocumented. It will not even appear in the standard help lists of identify command. This is simply:

# service unsupported-transceiver

After typing this in, it will pop up a warning message, but will make no other attempt to prevent you from proceeding. Theoretically, this will allow the switch to accept third-party hardware, but often a second command is necessary to disable the automatic port shutdown.

That second command is:

# no errdisable detect cause gbic-invalid

And that is really all it takes. At this time, your Catalyst should be prepared to accept any third-party SFP plugged into it, no matter what kind of suppliers.

Is There Any Reason Not To Use Third-Party Transceivers?

When you run the “service unsupported-transceiver” command, you get a rather harsh-looking warning message. However, all it actually says is that:

  1. Cisco will not give support for third party hardware,
  2. If a third party SFP damages the Catalyst, that’s outside your warranty,
  3. If the SFP is causing a problem, Cisco will require you to replace it with an official model before they’ll provide technical assistance.

What’s the reason to believe that it is possible third-party transceivers will cause problems? According to our experience, definitely not. If your SFP is well-made and buy from a reliable supplier, there’s no reason it should cause any problems. Optical transceivers is a very basic technology, and the possibility of even if it is a poorly made one causing actual damage are very minimum.

If you purchase your transceivers from a reliable supplier, they’ll be just as dependable as the Cisco branded units, but the cost is just a small part of the Cisco SFP Module.

Always Explore Your Choices In Network Upgrades

Even if you are “locked in” to a single networking brand or vendor, that does not mean you must have to use them for everything. The basic components, like optical transceivers, are so standardized that just about any reliable model will work perfectly well.

To find the most suitable for your network solutions: Fibre optic network solutions.

The Working Principle of the Optical Circulator

In fibre optical networks passive components such as optical isolators are essential for delivering of signals with minimum loss. Another type of passive element that is commonly used in fibre optic systems is the optical circulator. These devices that are used to direct the optical signal from one port to another port and in one direction only. This action prevents the signal from propagating in an unintended direction. Optical circulators have continued to increase their presence in a broad array of applications, including optical amplifiers, optical add and drop systems, dense wavelength-division multiplexing (DWDM Mux) networks and, optical time domain reflectometers (OTDRs).

In a 3-port circulator a signal is transmitted from port 1 to port 2, another signal is transmitted from port 2 to port 3 and, finally, a third signal can be transmitted from port 3 to port 1. This behavior is represented by the following.

Optical circulators

Figure 1 Conventional figure to represent the behavior of an optical circulator.

The name derives from the fact that a signal is transmitted from Port 1 to Port 2, another signal can be transmitted from Port 2 to Port 3 and, finally, a signal can be transmitted from Port 3 to Port 1. In practice, one or two ports are used as inputs and the third port is used as the output.

Two simple examples of optical circulators can be considered. The first is an EDFA amplifier (erbium doped fibre amplifier) application to amplify a signal. The configuration to do this with a three-port optical circulator is shown in the following figure.

a pump laser

Figure 2. Amplification of an input optical signal by a pump laser.

In the figure, a weak optical signal at 1550nm is input to Port 1 and is directed to Port 2. The weak signal at Port 2 is pumped by a 980nm pump lasers and the amplified signal is then transmitted from port 2 to the output Port 3.

In the second example, we consider the application of a Fibre-Bragg grating compensator to correct a distorted signal. This can also be done using a three-port optical circulator as shown in the following figure.

Fiber dispersion compersation

Figure 3. Fibre dispersion compensation of a distorted signal.

In the figure the distorted signal at Port 1 is conditioned by transmitting the delay distorted input signal to the input of Port 2. At Port 2 dispersion compensation is applied and the compensated (corrected) signal is transmitted to Port 3.

We now analyze the operation of the three-port optical circulator. We begin by considering the figure shown below.

Configuration of a three-port optical circulator

Figure 4. Configuration of a three-port optical circulator.

The components are a beam splitting polarizer (1), a reflection prism (2), two birefringent crystals (3,6), a Faraday rotator (4), and a half-waveplate (5). The upper figure (a) describes the propagation from Port 1 to Port 2 and lower figure (b) describes the propagation from Port 2 to Port 3.

Optical circulators can be used to achieve bi-directional optical signal transmission over a single fibre. Optical circulators is commonly used in WDM networks, polarization mode dispersion, chromatic dispersion compensation, optical add-drop modules (DWDM OADM), optical amplifiers, OTDR and fibre sensing applications. Fiberstore offer 3/4 ports polarization-insensitive optical circulator and 1310/1550/1064 polarization-maintaining (PM) optic circulators. Our fibre optical circulators can provide high isolation, very low insertion loss, low polarization dependent loss (PDL), low polarization mode dispersion (PMD), and excellent environmental stability. Any other wavelengths, without or with any connector can customised according to your requirement.

Related Article:  STP vs. UTP, Which One Is Better?

Guideline for Fixed Fibre Attenuator

Brand Compatible SFP For Optical Communications

SFP Transceivers for Telecommunications

The SFP is the more compact optical transceiver used in optical communications. It interfaces a network equipment mother board to a fibre optic or unshielded twisted pair networking cable.

This is probably the most diffused transceiver format available with a variety of different transmitter and receiver types, allowing users to select the appropriate transceiver for each link to provide the required optical reach over the available optical fibre (e.g., multimode fibre or single-mode fibre).

A drawing of a SFP transceiver is presented in Figure 1, where the particular connector for the input and output fibres that, with different dimensions, is present in all the transceivers is evidenced.

A drawing of a SFP transceiver

Figure 1. A drawing of a SFP transceiver

Optical SFP modules are commonly available in four different categories:850nm (SX), 1310nm (LX), 1550nm (ZX), and WDM, both DWDM and CWDM. SFP transceivers are also available with a copper cable interface, allowing a host device designed primarily for optical fibre communications to also communicate over unshielded twisted pair networking cable.

Commercially available transceivers have a capability up to 2.5 Gbit/s for transmission applications; moreover, aversion of the standard with a bit rate of 10Gbit/s exists, but it can be used only to connect nearby equipment, and is very useful to spare space and power consumption as interface in the client cards of line equipments.

Modern optical SFP transceivers support digital optical monitoring functions according to the industry standard SFF-8472 MSA. This feature gives the end user the ability to monitor real-time parametres of the SFP, such as optical output power, optical input power, temperature, laser bias current, and transceiver supply voltage.

SFP transceivers are designed to support SONET, Gigabit Ethernet, Fibre Channel, and other communications standards. A 1000 BASE SX SFP shown in Figure 2.

1000BASE-SX SFP 850nm

Figure 2. 1000BASE-SX SFP 850nm

One common query we hear is actually one must use a Cisco SFP with Cisco hardware? The answer is “not really” although that is not the answer Cisco wants to give. Perhaps you have used third-party compatible SFPs for your networking, and the price gap is obvious.

Brand’s SFPs And Third-Party Compatible SFPs

Brand’s SFPs such as Cisco, Cisco wants their customers buying only Cisco hardware, which is to say the least more expensive than anyone else on the market. They conduct their own optical transceivers, and try very hard to convince buyers that only official Cisco hardware will work.

Actually, a few of their hardware such as the Catalyst line will not even access third-party SFPs without running undocumented commands first!

That said, it’s simple enough to figure around. Plus, either way, the plain truth is that one optical transceiver from a reputable vendor is just as good as any other. It’s a totally standardized technology, like spark plugs, and one brand’s SFP is going to work fine with any other brand’s hardware.

And, like with spark plugs, few people beyond enthusiasts really care about the brand as long as the SFP works once installed.

When you are intending to upgrade your network, it makes sense to “cut corners” when those corners really aren’t even being cut at all. Third-party SFP optical transceivers usually cost far less than the “official” units, especially in the case of Cisco, but could supply the exact same performance you’d expect.

To get more brand compatible optical SFP transceivers, or other fibre optics equipment and any other questions you might have about your future networking needs, please don’t hesitate to contact FS.COM for everything you need to know!

Products Used in the Physical Layer

The Physical Layer, as the Layer 1 of ISO OSI Systems communications model where the mechanical and electrical specifications of physical network interface are defined. The physical network interface is considered passive network elements because they do not generate or alter data units traveling across the network. Network elements defined by the Physical Layer include (among others): Network transport media (cables) and connectors.

Network Media Types

Network media types used in Data Centre today are copper and fibre optic cables.

The following copper cables are available: Cat 1 to Cat 5, Cat 5E, Cat 6, Cat 6a, Cat7 and Twinax cables. Twinax copper cable with two conductors in a coaxial cable, which is slowly wrapped around each other; originally designed to replace RS-232 and has been redesigned for high-speed computer applications under 10 meters.

Fibre optic cable utilize light for data transmission, rather than electrical current on copper cables, Fibre optic cables have many advantages, for example, the are many times lighter and have substantially reduced bulk, no pins, a smaller and more reliable connector reduced loss and distortion, and are free from signal skew or the effects of electro-magnetic interference.

Cable Connector Types

Copper cable connectors. Currently, there are two copper connector standards are in use, RJ-45 and MRJ-21.

RJ-45: The most popular Ethernet connector in use nowadays. MRJ-21: Used in Brocade’s netlron MLX product family, provides 1GbE connectivity of up to 6 ports by the RJ-45 patch panel or RJ-45 connectors. It is a high-density, high-speed copper cable.

Optical cable connectors. Optical cable connector structure can be divided into: FC,SC, ST, LC, D4, DIN, MU, the MTP,MPO and so on in various forms.

Transceivers Are Either Copper or Optical

Copper transceivers, copper medium usually does not require any transceivers, as they are a part of the interface module. However, few of Brocade’s products use a copper SFP with an RJ-45 female connector for 1 GbE connectivity over copper medium, or XFP copper transceiver for 10GbE connectivity over CX4 copper. Figure 1 is a 1000BASE-T Gigabit Ethernet Full Duplex RJ45 100m Copper SFP Optical Transceiver.

copper sfp

Figure 1. Copper SFP Optical Transceiver

  • XFP 10GBASE-CX4: Uses a CX4 connector to provide a connection to up to 15 meters over CX4 grade copper cable.
  • SFP 1000BASE-TX: Uses a RJ-45 connector to provide a connection to up to 100meters over Cat5e or higher copper cable.
Optical transceivers.

The following optical transceivers are available: (Figure 2 is a CWDM SFP 40km Single-Mode Optical Transceiver)

cwdm sfp

Figure 2. CWDM SFP Optical Transceiver

  • SFP: Small form-factor Pluggable. Supports 100Mbps and 1Gbps Ethernet.
  • SFP+: Small Form-factor Pluggable Plus. Looks are physically identical to the SFP port but support higher speeds. Supports 10Gbps Ethernet. Might also support SFP transceivers.
  • XFP: 10 Gigabit Small Form-factor Pluggable. Supports 10Gbps Ethernet.
  • XENPAK: XENPAK transceiver is a hot-swappable I/O devices that plug into 10-Gigabit Ethernet module ports. The XENPAK transceiver is available in either optical or copper interfaces. It is used in typical router line card applications, storage, IP network and LAN.
  • X2: X2 transceiver is a standardized form factor for 10 Gb/s fibre optic transceivers that is used for data transfer rates from 10.3 Gb/s to 10.5 Gb/s. X2 transceiver is used in datacom optical links only (not telecom), and they are smaller than old generation XENPAK transceiver.
  • GBIC) Transceiver: A gigabit interface converter (GBIC) transceiver can send and receive data, which is to digitally convert media between a gigabit Ethernet network and a separate fibre optic based network.

SFP+ Twinax cables are copper cables with two SFP+ transceivers attached on either end. They are also known as Direct Attach Cables (DAC). Using SFP+ Twinax cable is significantly cheaper than connecting devices using two 10Gbps fibre optic transceivers over fibre cable. There are two types of SFP+ Twinax cables: active and passive. SFP+ Twinax cable provided by fs.com is available in lengths of 1m, 2m, 3m, 5m.

In addition, all those copper or optical products used in the Physical layer can be found in fs.com.