Tag Archives: optical transceiver

What is Optical Transceiver Module?

The speed and stability of the network is making a great leap forward thanks to the high bandwidth and low attenuation brought by fibre optics. Optical transceiver module is the major building block in fibre optic network, which conveys the information across communication channels for your optical systems. This article offers some rudiments about optical transceiver module and suggestions of choosing fibre patch lead for your transceiver module.

Working Principle of Optical Transceiver Module

An optical transceiver module is a device that uses fibre optical technology to send and receive data. The transceiver module has electronic components to encode or decode data into light pulses and then send them to the other end as electrical signals. To send data as light, it makes use of a light source, which is controlled by the electronic parts, and to receive light pulses, it makes use of a photodiode semiconductor.

Types of Optical Transceiver Module

Optical transceiver module is evolving rapidly to meet the escalating demand for speed and capacity. The tendency is that fibre optic transceiver module is evolving to have smaller size and higher data rate. The common types of optical transceiver module include GBIC, SFP, 10G SFP+, 40G QSFP+, CXP, CFP, CFP2, CFP4, CPAK and QSFP28.

The emergence of GBIC (Gigabit Interface Converter) is a milestone of transceiver module development, and it’s of epoch-making significance. As time went on, the size of transceiver was becoming smaller, so SFP (Small Form-Factor Pluggable) transceiver module came into being. It is half the size of GBIC, and it increases the port density of the same line card by two times. But this is not enough to meet the growing need of higher speed network connectivity. So 10G SFP+ (Small Form-factor Pluggable Plus) and 40G QSFP+ (Quad Small Form-factor Pluggable Plus) becomes new market favorites, for they have distinctly higher data rate and the same mini size as SFP. Besides, 100G optical transceiver module is also popular at present, with the types of CXP, CFP, CFP2, CFP4, CPAK and QSFP28. Various types of optical transceiver module can meet all kinds of customer’s requirements.


Optical Transceiver Module Parameters

Optical transceiver module has three main parameters which shows it’s capacity of connectivity. They are wavelength, data rate and cable distance.


Wavelength is the band of light used in the transmission of optical signals. The main wavelength of optical transceiver module is typically around 850, 1300 and 1550 nm, for the attenuation of the fibre is much less at those wavelengths. Besides, multi-mode fibre is designed to operate at 850 nm and 1300 nm, while single-mode fibre is optimised for 1310 nm and 1550 nm.

Data Rate

Data rate refers to how many bits of data the optic fibre carries per second. The widely applied data rates are 155Mbps, 1.25Gbps, 2.5Gbps and 10Gbps. The data rate of optical transceiver can provide backwards compatibility. So 155M optical transceiver module is also called FE transceiver, and 1.25G optical transceiver module is called GE transceiver.

Transmission Distance

Transmission distance is the distance an optical signal can be transmitted directly without amplification. The optical transceiver with the transmission distance shorter than 2km is classified to multi-mode optical transceiver module, while the optical transceiver with the transmission distance over 2km is classified to single-mode optical transceiver.

Except the above three parameters, optical transceiver module has other parameters, which are output power, receiving sensitivity, bias current, extinction ratio, saturated optical power and working temperature.

How to Choose Fibre Patch Lead for Transceiver Module

Optic transceiver modules are correspondingly connected with different fibre patch lead according to the type of their interface. When you choose a fiber patch cable, you need to consider the following factors: fiber type, transmission distance, data rate and transceiver interface.

We suppose that you need to choose a right patch cable used between fibre optic transceiver SFP-10G-SR and X2-10GB-SR. You know that SFP-10G-SR is 10GBASE-SR SFP+ transceiver module for MMF, 850-nm wavelength, LC duplex connector. And X2-10GB-SR is 10GBASE-SR X2 transceiver module for MMF, 850-nm wavelength, SC duplex connector. It’s easy to find that X2-10GB-SR needs SC connector, and SFP-10G-SR requires LC connector. So we should choose patch cable with SC-LC connector with MMF, 850-nm wavelength. In the same way, you can choose the proper fibre patch lead for your transceiver modules.



I believe that you get more familiar with optical transceiver module after knowing its’ types, parameters and how to choose fibre patch lead for it. You also need to know that, the chief advantage of optical technology is its high data transfer rate, which can in practice be several thousand times as fast as a cable modem Internet connection. And fibre optic transceiver plays an important role in fibre optical transmission. For purchasing more high quality optical transceiver modules with low cost or for more products’ information, please contact us at sales@fs.com.

Transceiver Solutions for Cisco Catalyst 9300 Series Switch

This year, Cisco unveiled the Catalyst 9000 family, shaping the new era of intent-based networking. The Network. Intuitive. The Cisco Catalyst 9000 Series switches are the next generation of enterprise-class switches built for security, Internet of Things (IoT), mobility, and cloud. The Cisco Catalyst 9000 Series switches come in three main varieties: The Catalyst 9300, the Catalyst 9400 and the Catalyst 9500. Here, the post will give an emphasis on Cisco Catalyst 9400 series switches and transceiver solution for them.

Overview of Cisco Catalyst 9300

The Catalyst 9300 Series is the next generation of the industry’s most widely deployed stackable switching platform. Built for security, IoT, and the cloud, these network switches form the foundation for Cisco’s Software-Defined Access, the leading enterprise architecture. In addition, the Cisco Catalyst 9300-based models support a variety of uplink modules for both copper and fibre uplink support. These models add even more flexibility to the interface choices that you can make in a single Cisco Catalyst 9300 Switch or in a stack of Cisco Catalyst 9300 Switches.

cisco catalyst 9300

Supported Transceiver Modules for Cisco Catalyst 9300

The Cisco Catalyst 9300 Series Switches support optional network modules for uplink ports. All modules are supported across all 9300 platforms:

  • 4 x 1 Gigabit Ethernet network module
  • 4 x 1, 2.5, 5, or 10 Gigabit Ethernet network module
  • 8 x 10 Gigabit Ethernet network module
  • 2 x 40 Gigabit Ethernet network module

100G Solution

Model Number Transceiver Description Interface Max Cable Distance
CFP-100G-SR10 100GBASE-SR10 CFP form factor transceiver module for multi mode fibre, short wavelength over 10 lanes, in the 850-nm wavelength window MTP/MPO-24 Up to 100m on OM3/<150m on OM4
CFP-100G-LR4 100GBASE-LR4 CFP form factor transceiver module for SMF, 4 LAN-WDM lanes in the 1310-nm wavelength window LC duplex 10km
CFP-100G-ER4 100GBASE-ER4 CFP form factor transceiver module for SMF, 4 LAN-WDM lanes in the 1310-nm wavelength window LC duplex 40km
QSFP-100G-SR4-S 100GBASE-SR4 QSFP form factor transceiver module for multi mode fibre, short wavelength over 4 lanes, in the 850-nm wavelength window LC duplex 100m
QSFP-100G-CWDM4-S 100GBASE CWDM4 QSFP form factor Transceiver for single mode fibre, 4 CWDM-WDM lanes in the 12761-1331-nm wavelength window LC duplex 2km
QSFP-100G-PSM4-S 100GBASE PSM4 QSFP form factor transceiver module for single mode fibre, short wavelength over 4 lanes, in the 1195-1325-nm wavelength window MTP/MPO-12 500m
QSFP-100G-LR4-S 100GBASE-LR4 QSFP form factor transceiver module for SMF, 4 LAN-WDM lanes in the 1310-nm wavelength window LC duplex 10km

40G Solution

Model Number Transceiver Description Interface Max Cable Distance
QSFP-40G-SR4 40GBASE-SR4 QSFP+ transceiver module for MMF, 4-lanes, 850-nm wavelength MTP/MPO 150m on OM4
QSFP-40G-CSR4 40GBASE-CSR4 QSFP+ transceiver module for MMF, 4-lanes, 850-nm wavelength MTP/MPO 400m on OM4
QSFP-40G-SR4-S 40GBASE-SR4 QSFP+ transceiver module for MMF, 4-lanes, 850-nm wavelength MTP/MPO 150m on OM4
QSFP-40G-SR-BD 40G QSFP Bi-Directional transceiver module for duplex MMF LC duplex 150m on OM4/100m on OM3/30m on OM2
QSFP-40G-ER4 40GBASE-LR4 QSFP40G transceiver module for Single Mode Fibre, 4 CWDM lanes in 1310nm window Muxed inside module LC duplex 40km
QSFP-40GE-LR4 100GBASE-LR4 QSFP form factor transceiver module for SMF, 4 LAN-WDM lanes in the 1310-nm wavelength window LC duplex 10km
WSP-Q40GLR4L 40GBASE-LR4 QSFP40G transceiver module for Single Mode Fibre, 4 CWDM lanes in 1310nm window Muxed inside module LC duplex 2km

25G Solution

Model Number Transceiver Description Connector Type Cable Type
SFP-H25G-CU1M 25G Copper Cable 1-meter SFP28 to SFP28 Passive Copper Cable
SFP-H25G-CU2M 25G Copper Cable 2-meter SFP28 to SFP28 Passive Copper Cable
SFP-H25G-CU3M 25G Copper Cable 3-meter SFP28 to SFP28 Passive Copper Cable
SFP-H25G-CU5M 25G Copper Cable 2-mete SFP28 to SFP28 Passive Copper Cable
SFP-25G-SR-S 25GBASE-SR SFP+ transceiver module for MMF, 850-nm wavelength LC duplex MMF

10G Solution

Model Number Transceiver Description Interface Max Cable Distance
SFP-10G-SR 10GBASE-SR SFP+ transceiver module for MMF, 850-nm wavelength LC duplex 300m over OM3
SFP-10G-SR-S 10GBASE-SR SFP+ transceiver module for MMF, 850-nm wavelength LC duplex 300m over OM3
SFP-10G-SR-X 10GBASE-LRM SFP+ transceiver module for MMF and SMF, 1310-nm wavelength LC duplex 300m over OM3
SFP-10G-LRM 10GBASE-LRM SFP+ transceiver module for MMF and SMF, 1310-nm wavelength LC duplex 220m
SFP-10G-LR 10GBASE-LR SFP+ transceiver module for SMF, 1310-nm wavelength LC duplex 10km
SFP-10G-LR-S 10GBASE-LR SFP+ transceiver module for SMF, 1310-nm wavelength LC duplex 10km
SFP-10G-LR-X 10GBASE-LR SFP+ transceiver module for SMF, 1310-nm wavelength LC duplex 10km
SFP-10G-ER-S 10GBASE-ER SFP+ transceiver module for SMF, 1550-nm LC duplex 40km
SFP-10G-ZR 10GBASE-ZR SFP+ transceiver module for SMF, 1550-nm LC duplex 80km
SFP-10G-BX40D-I 10G SFP+ Bidirectional for 40km, downstream LC duplex 40km
SFP-10G-BX40U-I 10G SFP+ Bidirectional for 40km, upstream LC duplex 40km
DWDM-SFP10G-49.32 10GBASE-DWDM 1549.32 nm SFP+ (100-GHz ITU grid) LC duplex 40km
DWDM-SFP10G-60.61 10GBASE-DWDM 1560.61 nm SFP+ (100-GHz ITU grid) LC duplex 40km
CWDM-SFP10G-1470 CWDM 1470 nm SFP+ 10 Gigabit Ethernet Transceiver Module LC duplex 20km
CWDM-SFP10G-1490 CWDM 1490 nm SFP+ 10 Gigabit Ethernet Transceiver Module LC duplex 20km
XENPAK-10GB-ER 10GBASE-ER XENPAK transceiver module for SMF, 1550-nm wavelength SC duplex 40km
XENPAK-10GB-LR 10GBASE-LR XENPAK transceiver module for SMF, 1310-nm wavelength SC duplex 10km
X2-10GB-LR 10GBASE-LR X2 transceiver module for SMF, 1310-nm wavelength SC duplex 10km
X2-10GB-SR 10GBASE-SR X2 transceiver module for MMF, 850-nm wavelength SC duplex 300m over OM3 MMF
XFP-10GLR-OC192SR Cisco multirate XFP transceiver module for 10GBASE-LR Ethernet and OC-192/STM-64 short-reach (SR-1) Packet-over-SONET/SDH (POS) applications,SMF LC duplex 10km
XFP-10GER-OC192IR Cisco multirate XFP transceiver module for 10GBASE-ER Ethernet and OC-192/STM-64 intermediate-reach (IR-2) Packet-over-SONET/SDH (POS) applications, SMF LC duplex 40km


Digital disruption is changing how we think about our networks. Whether customers or employees, the “experience” has become a strategic imperative. The Cisco Catalyst 9300 Series fixed access switches are designed to help you change your network from a platform of connectivity to a platform of services. If you are in need of compatible optical transceivers for Catalyst 9300, give FS.COM a shot. FS.COM provides a wide range of supported optical transceivers for Cisco Catalyst 9300 series switch. Each one of them has been tested with assured 100% compatibility to them.

Related Article: Cisco Catalyst 3750 Series Switches SFP Port Connections

What Distance Can 100G QSFP28 Transceiver Support?

The rapid growing bandwidth keeps driving the need for 100G transceivers to build data centres, enterprise, long-haul networks. Just as 1G, 10G optical modules, 100G QSFP28 transceivers also have single-mode and multimode categories to support short and long distance network links. So what kind of QSFP28 transceivers are included? What distance can each QSFP28 support?

100G QSFP28 – Supported Distance Below 1km

Multimode 100G QSFP28 modules are used for short distance applications, such as QSFP28 Cisco QSFP-100G-SR4-S 100GBASE-SR4 transceiver. It provides 100GBASE-SR throughput at a wavelength of 850 nm by connecting with multimode MTP/MPO cable. It can support the link lengths up to 70 m over OM3 MPO fibre patch lead and 100 m over OM4 MPO fibre patch lead.100g qsfp28 sr4

But there is a special 100G QSFP28 transceiver–QSFP-100G-PSM4-S. This QSFP28 is a single-mode transceiver. It carries 100G data over 12-fibre single-mode MPO fibre patch cords. However, the maximum link lengths it can support is only 500 metres.

100G QSFP28–Supported Distance From 1km-10km

To support long distance signal transmission, single-mode transceivers are generally selected. The following will list some 100G QSFP28 modules which can reach the link distance from 1 km to 10 km.

QSFP28 100GBASE-CWDM4. This transceiver applies WDM multiplexing and demultiplexing technique and carries 100G Gigabit Ethernet signal over four wavelengths. Different from the above two 100G QSFP28 optics, it’s configured with duplex LC interfaces. With QSFP28 100GBASE-CWDM4 modules, you can build networks with link lengths up to 2 km over single-mode duplex LC patch cords.

QSFP28 100GBASE-LR4. This hot-pluggable 100G QSFP28 form factor can support 103.1Gbps data rate. It’s compliant with the QSFP28 MSA and IEEE802.3ba 100GBASE-LR4. The 100G data is transmitted over four wavelengths. Because of multiplexing and demultiplexing within this QSFP28 transceiver, it matches duplex LC patch cords. And it can support links up to 10 km over single-mode LC fibre cable.

100g qsfp28 lr4

100G QSFP28–Supported Distance Over 10km

In fact, 10km link lengths of 100G can’t meet users’ demands. So 100G QSFP28 which can support over 10km lengths are needed to build long-haul network. Due to the optic package size and the maximum power, the distance supported by 100G QSFP28 transceivers are restricted. Vendors are required to research and develop optics that allow for existing high power components and devices to consume lower power in a smaller space. It’s said there are 100G QSFP28 ER4 and 100G QSFP28 ZR4 transceivers in the market. Each can support the maximum network link lengths up to 30 km and 80 km. But consumers can’t easily get those 100G QSFP28 modules. But we believe that ER4 and ZR4 technology will be available in the market sooner or later.

At present, if your switch ports are QSFP28 and you need to build 100G network links over 10km, you are suggested to apply amplification technology. The other method is 100G CFP ER4 that support 40km link lengths. Of course your switch port should be CFP or you can find a device to convert QSFP28 to CFP.


Now people can get 100G QSFP28 transceivers for link lengths up to 10 km. Yet not too many transceiver vendors have enough stocks. In the Internet era, what is important is the speed. Thus, seek for reliable vendors who have huge stocks of QSFP28 like FS.COM. And we will release 100G-QSFP28-ER4 and 100G-QSFP28-ZR4 in the future to support longer distances.


Check out All CWDM Transceiver Modules

Coarse Wavelength Division Multiplexing (CWDM) is one of WDM technologies. It uses up to 20 different wavelengths for data transmission over a single fibre. CWDM applies coarse wavelength grid and it allows low-cost, uncooled lasers, which makes CWDM systems less expensive and consuming less power. There are many optical equipment applying CWDM technology. This article will introduce CWDM transceiver.

cwdm transceiver module

CWDM Transceivers

CWDM transceiver is a kind of optical modules employing CWDM technology. CWDM transceiver enables connectivity between existing network equipment and CWDM Multiplexers/DeMultiplexers (Mux/DeMux). When used with CWDM Mux/DeMux, CWDM transceiver can increase network capacity by transmitting multiple data channels with separate optical wavelengths (1270 nm to 1610 nm) over the same single fibre. CWDM transceivers are also useful for reducing network equipment inventories by eliminating the need to maintain surplus units/ devices of various fibre types for network repairs or upgrades. CWDM transceiver includes four types, such as CWDM SFP, CWDM SFP+, CWDM XFP and CWDM X2. The following shows more details about these CWDM transceiver modules.

CWDM Transceiver Module Types

CWDM SFPs are hot-pluggable transceiver modules. CWDM SFP transceivers are SFP MSA (Multi Sourcing Agreement) and IEEE 802.3 & ROHS compliant. CWDM SFPs can provide data rates including 1G, 2G and 4G over the link distance of up to 200 km by connecting with duplex LC single-mode patch cords. CWDM SFPs transmit multiple data channels by combining separate optical wavelengths onto a single fibre to increase network capacity. CWDM SFPs can be used to support the CWDM passive optical system combing CWDM OADM (optical add/drop multiplexer). When CWDM SFPs used with transponders and media converters, these two optical components offer convenient method to convert existing legacy equipment with standard wavelengths or copper ports to CWDM wavelengths.

CWDM SFP+ offers service providers and enterprise companies an easy way to get a scalable 10 Gigabit Ethernet network. It is a cost-effective solution for 10 Gigabit Ethernet applications in campus, data centre and metropolitan area access networks. CWDM SFP+ can transport up to eight channels of 10 Gigabit Ethernet over single-mode fibre strands at the wavelengths including 1610 nm, 1590 nm, 1570 nm, 1550 nm, 1530 nm, 1510 nm, 1490 nm, and 1470 nm. CWDM SFP+ solution is helpful to increase the bandwidth of an existing 10 Gigabit Ethernet optical infrastructure without adding new fibre strands. The solution can be used in parallel with other SFP+ devices on the same platform.

CWDM XFP is a hot-pluggable module designed in Z-direction and mainly used for typical routers and switch line card applications. CWDM XFP transceivers are designed for Storage, IP network and LAN. They comply with CWDM XFP MSA. CWDM XFPs cover the wavelengths from 1270 nm to 1610 nm. These modules can support the distance up to 100 km, which depends on the wavelengths, fibre types and the CWDM Mux/DeMux insertion loss.


CWDM X2 transceiver is designed for CWDM optical data communications such as 10G Ethernet and 10G Fibre Channel applications. CWDM X2 wavelengths are available from 1270 nm to 1610 nm. CWDM X2 is MSA Compliant. It supports the transmission distance up to 80 km connecting with duplex SC single-mode fibrecable.


CWDM technology provides a low-cost solution which allows scalable and easy-to-deploy Gigabit Ethernet and Fibre Channel services. CWDM transceiver enables a more flexible and highly available multi-service network with the combinations of CWDM OADMs and CWDM Mux/DeMux. FS.COM offers all kinds of CWDM transceiver like CWDM SFP, CWDM SFP+, CWDM XFP, CWDM X2. Our CWDM transceivers are compatible with most famous brands and all these optics have been fully tested to make sure high compatibility. For more details about FS.COM CWDM transceiver and other CWDM equipment, please visit our site www.fs.com or contact us via sales@fs.com.

What’s the Difference Between Cisco GLC-SX-MM and Cisco GLC-SX-MMD?

Cisco 1000BASE SFPs keep a huge market share in the optic area. Cisco SFPs offer users optical solutions for long distance and short distance transmission. For short distance, there are 1000BASE SX SFP, such as Cisco GLC-SX-MM and Cisco GLC-SX-MMD. Though these two modules have great similarity, they are actually different. Then what’s the difference? This article will introduce the details of Cisco GLC-SX-MM and Cisco GLC-SX-MMD SFP transceiver modules.



Cisco GLC-SX-MM 1000BASE-SX SFP is a duplex transceiver for short distance transmission, operating at the wavelength of 850 nm at the data rate of 1Gbps. It connects with OM2 multimode LC patch cords supporting up to 550 meters. The hot-swappable 1000BASE-SX SFP is compatible with the IEEE 802.3z 1000BASE-SX standard. And it’s RoHS compliant.


Cisco GLC-SX-MMD 1000BASE-SX SFP is another type of hot-swappable optical transceiver for short reach data transmission. This 1000Base-SX transceiver supports data rates up to 1.25Gbps. Same to Cisco GLC-SX-MM SFP, it also has duplex LC interference. Connecting with OM2 MMF, it can support the distance up to 550 meters. It’s compliant with SFP Multi-Source Agreement (MSA) standards. Cisco GLC-SX-MMD is composed of five parts: the LD driver, the limiting amplifier, the digital diagnostic monitor, the VCSEL laser and the PIN photo-detector. The Digital Diagnostic Monitoring (DDM) function is its special feature.


From the above content, you can see the main difference between these two transceivers is the DDM. When you buy SFP transceivers in the market, you may come across this selection difficulty whether to choose an SFP with DDM or not. So what’s DDM?

DDM is short for digital diagnostic monitoring. It’s also known as diagnostic optical monitoring (DOM). Diagnostic monitoring interface outlined in the SFF-8472 MSA is an extension of the serial ID interface defined in the GBIC specification, as well as in the SFP MSA. Today, many SFP transceivers have the function of digital diagnostics monitoring according to the industry standard MSA SFF-8472. It provides the important information about the status of the transmitted and received signals. This approach allows for better fault isolation and error detection.

DDM mainly plays the role in two sides: monitoring and warning. It monitors detailed information about a transceiver. And it offers a system of alarm and warning flags which alert the host system when particular operating parameters are not in line with the normal operating parameters set by the factory. So users can find out the fault isolation according to outcomes of DDM, and predict failure possibilities and prevent such fault.

Real-time monitoring—With a 2-wire serial bus (also known as “I2C” or “I2C” protocol), digital diagnostics can monitor the SFP module’s temperature, receiver power, transmitter bias current, and transmitter power by a microcontroller inside the transceiver. Usually, the output of the physical value of each parameter is an analog voltage or current from the Trans impedance amplifier, the laser driver, or the post amplifier. Then the digitalised value can be processed as part of a control loop, trigger an alarm, or just record the data into a register.

Calibration and warning thresholds—In addition to generating digital readings of internal analog values, DDM can also produce various status bits. Calibration and warning thresholds value is made during the device manufacturing process. Comparing current values generated by DDM and factory preset limits, users will know whether or not the transceivers have met the desired operation requirements.

FS.COM Cisco Compatible GLC-SX-MM SFPs

FS.COM brings Cisco compatible 1000BASE-SX SFPs including GLC-SX-MM and GLC-SX-MMD SFPs.
The 1000BASE-SX standard optics are developed to support lower cost multi-mode fibre runs in horizontal and shorter-length backbone applications. The following figure shows two Cisco GLC-SX-MM SFP transceivers are connected by an LC MMF patch cable.


Item Part No. Description
a. 11774 Cisco GLC-SX-MM Compatible 1000BASE-SX SFP 850nm 550m Transceiver
b. 43132 2M LC UPC to LC UPC Duplex 2.0mm PVC(OFNR) OM2 Fibre Optic Patch Cable
b. 11774 Cisco GLC-SX-MM Compatible 1000BASE-SX SFP 850nm 550m Transceiver

Note: you can use GLC-SX-MMD SFPs to replace GLC-SX-MM SFPs for shorter-length backbone application, too.


This article introduces Cisco GLC-SX-MM and Cisco GLC-SX-MMD SFP transceivers. Both kinds can realise short distance connection. The difference is that GLC-SX-MMD has DDM function while the other has no. So it’s up to you to decide whether you need DDM function to monitor parameters of the SFP. Fiberstore supplies optical transceivers with DDM and without DDM to satisfy customers’ different needs. If you need more information, please contact us via sales@fs.com or visit our site www.fs.com/uk.

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

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.

A PON Based on Code-division Multiplexing Access

Because of the Internet and broadband networks were introduced, the emerging applications – such as teleconferencing, video on demand, and high quality audio transmission has strict high flux optical access network quality of service (QoS) capabilities. However, the infrastructure of current access networks suffers from limited bandwidth, high network-management costs, poor flexibility, and low security, which prevent networks from delivering integrated services to their users. Due to sophisticated optical components and electronic circuits, optical fiber links has become used in access networks. Passive optical network (PON) and different multiplexing technology is put forward under this background, including the wavelength division multiplexing (WDM), 1 time division multiplex (TDM), 2 and optical code division multiplexing (OCDM).

PONs have been standardized for FTTH solutions and are deployed by network-service providers worldwide. Even though PONs based on TDM (TDM-PON) effectively use fiber bandwidths, they have limitations regarding transmission speed, burst synchronization, security, dynamic bandwidth allocation, and ranging accuracy. Wavelength division multiplexing (WDM) technology has also been proposed for PONs. When used in conjunction with PONs (WDM-PON), this emerging technology becomes more favorable as the required bandwidth increases, but it failed to attract attention from industry due to the high cost of optical component. Other schemes for optical access networks are currently under study worldwide.

Optical code division multiplexing access (OCDMA) systems have attracted attention in recent years, because the number of advantages, including its asynchronous access ability and flexibility of user distribution, support for variable bit rate, traffic and security “bursts” unauthorized users. OCDMA is an very attractive multi-access technique for access systems like local-area networks and the first mile, but no detailed network -design schemes have been developed to date. A PON based on code-division multiplexing access (CDMA) has been proposed using pseudo-random and Walsh codes for user identification. However, signature processing for multiple access is done in the electrical domain using an application – specific integrated circuit (ASIC), and not in the optical field as we are pursuing.

We have developed the OCDMA-PON, a network structure of PON in conjunction with OCDMA, i.e., a different multiple-access technology from TDM and WDM. OCDMA technology achieves signature processing light rather than the electrical domain using an optical encoder/decoder.

Optical-line terminator (OLT) of the optical-code-division multiplexing access/passive optical network (OCDMA-PON) system. Rx, Tx: Receiver, transmitter. OOC: Optical orthogonal code. ODN: Optical distribution network. ONU: Optical network unit. ONT: Optical network termination. n: Counter.

For the forward channels, the source is encoded at the OLT and the downstream signal is transmitted at a wavelength of 1550nm. Every user is a assigned a unique optical orthogonal code and identified by a correlation operation at the optical decoder based on fiber Bragg gratings (FBGs). To reduce multi-user interference (MUI), the nonflattened source spectrum can be compensated by a flatness +compensator before entering the FBG encoder. Another benefit is a flattened source is that it relaxes the accuracy requirements regarding the achievable precision with which the phase can be controlled and maintained stably when the number of users increases. For the backward channel from the optical network unit (ONU) optical network terminal (ONT) to the OLT, the upstream is transmitted at a wavelength of 1310nm. After upstream traffic passes the optical transceiver module, which it is sent to multiple decoders, each of which recovers the information for each user.

Upstream of a stable wavelength is usually required with a stabilized laser source at the ONU’s transmitter. The downstream signal from the OLT to ONU/ONT passes through a circulator to the detector, where the user’s information is separated through optical correlation with his or her unique OCC using a balanced receiver. The downstream control signal is also obtained and the control unit is passed to the network. For the upstream, the signal from the ONU to the OLT is encoded by the OCC for user identification by the optical encoder. This is then transmitted through optical fiber link from tifert. Our scheme has several advantages. For example, any user may add or drop into the network at random and the network is running asynchronously.

Our OCDMA-PON system is composed of an OLT and an ONU. Every ONU is identified by its own cde address. The signal is modulated with both frame information and an address-code sequence. The former is used to complete the data load switch, which help to identify different users.

Figure 1 compares the bit-error rate (BER) with the ONU-transmitter input power for two cases, one affected by interference (for example, MUI or from different noise contributions) and a second based on a back to back configuration. In this case, we assume that the amount ONUs/ ONTs is 30 and the bit rate of downstream flow is 1.25gb/s. We found that the sytem that includes interference exhibits much worse performance than that using the back to the back configuration, with approximately 6dB penalty at a BER of 10−9. For the OCDMA-PON, we confirm that MUI is the dominant degradation source (see Figure 3) and must be included in the network design.

Figure 1. Performance of the OCDMA-PON for back-to-back configuration and with interference. N-active: Number of active users. R-downstream: Downstream-traffic bit rate.

Figure 2 compares the BER performance as the number of active users increases for the CDMA-PON and OCDMA-PON systems. We assumed that the bit rate of downstream traffic is 1.25Gb/s for a fiber-link length of 10km. The OCMDA-PON scheme exhibits a similar performance to the CDMA-PON when the number of users is large. For example, for 30 users and a BER of 10−9, OCDMA-PONs can only increase the number of users compared to that supported by CDMA-PONs by 10%. However, the advantage of OCDMA-PONs over CDMA-PONs becomes obvious when the number of users supported by the OCDMA-PON is small (see Figure 4). Note that the signature is processed in the electrical domain by ASIC with Walsh code for user identification in CDMA-PONs, while the optical domain is used by the FBG encoder/decoder based on source-spectrum flattening and a balanced detector with the prime codes for user identification in OCDMA-PONs. Taking into account the higher bit rate and higher bandwidth offered by OCDMA-PONs based on optical processing of user signatures, we still prefer an OCDMA-PON scheme with intensity modulation. To further improve the performance of the OCDMA-PON, we need to solve the MUI-imposed degradation problems and improve the optical encoder/decoder.

Figure 2. CDMA-PON versus OCDMA-PON comparison as the number of ONUs/ONTs increases. L: Length.

Our OCDMA-PON system is different from classical PONs in that OCDMA is used for multiple-user access instead of TDM or WDM, and the OCDMA-PON scheme combines the advantages of both the PON and OCDMA technologies, including flexible network assembly, fair bandwidth division, differentiated services or QoS in teh physical layer, Asynchronous access, support for variable bit rate and burst, and the security of an unauthorized user traffic. Based on comprehensive comparisons between the OCDMA-PON and the previously studied CDMA-PON, we find that the former scheme exhibits a better BER performance than the latter for small numbers of users.

In summary, OCDMA-PON offers several advantages over CDMA-PON, including higher bit rate, higher bandwidth, and better security against unauthorized users. We continue to work towards realizing an experimental demonstration of the OCDMA-PON system.