400G CDFP Vs. CFP8 Module

400 Gigabit Ethernet was planned to be released in December this year. It is designed to meet IEEE P802.3bs Task Force standard and to apply to both metro and long-haul networks. The 400GbE operates over 100 m of multimode fiber, 500 m of singlemode fiber, 2 km of SMF, and 10 km of SMF. 400G CDFP and CFP8 are two form factors of 400G Ethernet technology. This article would give a introduction to 400G CDFP and CFP8 modules and make a comparison between them.

400G Ethernet

Introduction to 400G CDFP Module

The CDFP is short for 400 (CD in Roman numerals) Form factor Pluggable, which is designed to provide a low cost, high density 400 Gigabit Ethernet solution. It features as front panel, hot-pluggable, 16 channel and 400 Gbps module. CDFP will be a short reach module, which enables 4 Terabit line cards. From the perspective of interface, it is very similar to the QSFP and CXP modules. CDFP developers have targeted using the developing IEEE802.3bs specification for Ethernet 400GBaseSR, 400GBaseLR.

  • 5 meter direct attach cables
  • 100 meter multimode fiber
  • 500 meter parallel singlemode fiber
  • 2 kilometers of duplex singlemode fiber

400G CDFP Module

Figure2: 400G CDFP Module

Information About 400G CFP8 Module

Following CFP2 and CFP4 naming, CFP8 module was proposed in the year 2015. CFP8 is a new form factor which is still under development by members of the CFP multisource agreement (MSA). The form factor of CFP8 is amounting to CFP2, but it supports 4 × 100G and 400G, for example, 4×CFP2’s 1×100G. The CFP8 uses a new 16 × 25G electrical I/O connector. The CFP8’s interface has been generally specified to allow for 16 × 25 Gb/s and 8 × 50 Gb/s mode. From the point of bandwidth density, the CFP8 module is eight times larger than the CFP module and four times larger than the CFP2 module.

400G CFP8 module operation

Figure3: 400G CFP8 module operation

Example IEEE specifications supported by CFP8:

  • 400GBASE-SR16 parallel MMF (16x25G NRZ)
  • 400GBASE-FR8/LR8 duplex SMF (8x50G PAM4 WDM)
  • 400GBASE-DR4 parallel SMF (4x100G PAM4)
  • CDAUI-16, CDAUI-8

Form factors of CFP modules

Figure4: Form factors of CFP modules

Among all the specifications on the above, 400GBaseDR4 is the most revolutionary one. 400GBaseDR4 uses 4x100G parallel SMF PAM4 signaling technology. This technology is also aimed at fitting in the CFP4 21.5-mm width module size, while using 12 (SMF) fibers within a 1×12 MPO optical connector and the host board electrical 56-pin edge connector.

Low power consumption is also a distinctive feature of CFP8. Active optical modules have been widely deployed in the process of data transmission, but some of them or some copper applications really cost a lot and consumes much power. CFP8 module uses internal mid-board optical or electrical interconnect flyovers and bulkhead MPO or MXC connectors to connect the switch. This reduces power consumption to a great extent.

400G CFDP Vs. CFP8
—Form factor

CDFP was proposed earlier than CFP8, it has larger form factor than CFP8.

—Supported fiber type

CDFP supports passive and active copper cable, active optical cable and multimode fiber while CFP8 supports singlemode and multimode fiber.

—Transmission distance

CFP8 modules support longer data link distance compared with CDFP modules.


The CDFP modules provide a very versatile solution for data center interconnects. CFP8 would be used in high-density 4x100GbE fan-out applications, such as datacom applications or in ITU-T for telecom applications.


This article mainly discussed about CDFP, CFP8 and their differences in form factor, supported fiber type, transmission distance and applications. There is no doubt that 400G Gigabit Ethernet is an irresistible trend for future Ethernet development.

Intel Network Adapters for Dell PowerEdge R710 Servers

With the growing prevalence of Dell PowerEdge Servers, Dell PowerEdge R710 servers gradually caught Ethernet users’ eyes for its competitive price, superb quality and low power consumption. As one part of the Dell PowerEdge Select Network, Intel Ethernet Network Adapters are high performance adapters for 1/10/25/40GbE Ethernet network connections. This article would give a brief introduction to Dell R710, Intel NDC for Dell R710 and optics for Intel NDC.

About Dell PowerEdge R710

The Dell PowerEdge R710 is a 2U rack server that can support up to two quad- or six-core Intel Xeon 5500 and 5600 series processors and to eight SATA or SAS hard drives, giving you up to 18TB of internal storage. It has 18 memory slots allow for a maximum of 288GB of memory, allowing the R710 to support and memory-intensive task you can throw at it. It has low power consumption and high performance capacity, which helps you save both money and time. We would provide detailed information about Dell PowerEdge R710 in the next two parts.

Dell R710 2U Rack Server

Figure1: Dell R710 2U Rack Server

Dell R710 Dimensions

Dell R710 Dimensions

Main Features:

Dell PowerEdge R710 adapted Intel’s E5-2600 processors, which have up to 20MB cache and up to 8 cores versus the 5500 and 5600 processors which max out at 12MB Cache and 6 cores. These 8-core processors are ideal for increased security, I/O innovation and network capabilities, and overall performance.


The R710 supports a high level of internal storage maxing out at 18TB. That includes up to six 3.5″ hard drives or eight 2.5” hard drives. It provides support for 6Gb/s SAS, SATA, and SSD drives.


The R710 sports Dell’s new iDRAC6 management controller, which has a dedicated network port at the rear of the server. It provides a web browser interface for remote monitoring and viewing the status of critical server components, and the Enterprise upgrade key brings in virtual boot media and KVM-over-IP remote access.

—Remote Management

Based on Symantec’s Altiris Notification Server, the Management Console takes over from Dell’s elderly IT Assistant and provides the tools to manage all your IT equipment, instead of just Dell servers. Installation is a lengthy process, but it kicks off with an automated search process that populates its database with discovered systems and SNMP-enabled devices.

Intel network Adapters for Dell PowerEdge R710 servers

According to Dell PowerEdge R710 datasheet, the Dell PowerEdge R710 servers support dual port 10GB enhanced Intel Ethernet server adapter X520-DA2. This Dell Intel Ethernet Network Daughter Card X520/I350 provides low cost, low power flexibility and scalability for the entire data center. The Intel Ethernet Network Daughter Card X520-DA2/1350-T2 provides two 1000BASE-T ports and two 10G SFP+ ports as shown in Figure 2 to support 1GbE/10GbE Ethernet network connectivity.

Intel Ethernet Network Daughter Card X520-DA2

Figure2: Intel Ethernet Network Daughter Card X520-DA2

Cables And Optical Modules for Intel NDC X520-DA2

As we mentioned before, the Intel Ethernet Network Daughter Card X520-DA2 provides two 1000BASE-T ports and two 10G SFP+ ports respectively. We can plug two Intel compatible SFP transceivers into the two 1G ports on the Intel NDC X520-DA2 respectively to achieve 1G network connection. Likewise, we can also connect Intel compatible SFP+ transceiver to the 10G port on the Intel card for making 10G data transferring. In addition, we can also use Direct Attach Cable (DAC) to achieve 10G network connectivity, such as 10Gb fibre optic cable, Intel 10G SFP+ DAC cable. DAC cables are suitable for data transmission over very short link length while optical modules are more appropriate for longer transmission distance.

Intel NDC X520-DA2 with 10G optical modules

Figure3: Intel NDC X520-DA2 with 10G optical modules


The Dell PowerEdge R710 server with the high performance of Intel Ethernet Network Daughter Card X520-DA2 offers you a 2U rack to efficiently address a wide range of key business applications. With the great Intel NDC card, it also provides you a perfect solution for 1G and 10G Ethernet network connectivity. You can rest assured to enjoy a low consumption but high capacity server to keep your business.

Broadcom or Intel Network Adapter for Dell PowerEdge Server?

The NDC, Network Daughter Card (also known as Select Network Adapters), is an innovation technology developed by Dell. As an advanced technology on server, the NDC provides the customers with a flexibility of choosing what they want ( 4 x 1GbE, 2 x 10GbE or 2 x Converged Network Adapter.) With this small, removable mezzanine card, we are no longer limited to use network interface cards (NICs) on the motherboard. And it has been used in the twelfth-generation Dell PowerEdge server. This article will focus on Broadcom or Intel network adapter for Dell PowerEdge Server.

About Select Network Adapter

Network adapter plays an irreplaceable role in a server system, as it can reduce CPU usage on the server, which improves the overall system performance. NDC is a paramount member of Dell PowerEdge Select Network Adapters family. There are two form factors of Select Network Adapters—blade servers and rack servers. (You can see the two servers clearly in the following figure.) The Blade Select Network Adapter provides dual port 10GbE from various suppliers. The Rack Select Network Adapter provides a selection of 1GbE and 10GbE port options, such as 1000Base-T, 10GBASET and 10Gb SFP+.

Rack Mount Servers & Blade Servers

Figure1: Rack Mount Servers & Blade Servers

PowerEdge Platforms That Support Select Network Adapters

The Blade Select Network Adapter is offered on the PowerEdge M620 blade server.

The Rack Select Network Adapter is offered on the following PowerEdge platforms:

  • R620
  • R720
  • R720xd

PowerEdge R720 Rack Server

Figure2: PowerEdge R720 Rack Server

Available NDC options
PowerEdge rack servers:
  • Broadcom 5720 Base-T
  • Intel I350 Base-T
  • Broadcom 57800 Base-T and SFP+
  • Intel x540 Base-T
PowerEdge blade servers:
  • Broadcom 57810S KR
  • Intel x520 KR
  • QLogic QMD8262 KR
Form factors of Blade Servers & Rack Servers

Blade servers: There are three form factors of blade servers offered by Dell: Intel x520 Dual Port 10Gb KR NDC, Broadcom 57810S Dual Port 10Gb KR NDC, and QLogic QMD8262-k Dual Port 10Gb KR NDC. Both the Broadcom and Intel blade NDCs will support both 1Gb and 10Gb speeds, while the QLogic blade NDC will run only at 10Gb speeds.

Rack servers: There are mainly two brands of NDC support rack servers—Intel and Broadcom, which would be further explained as follows:

  •  Intel Ethernet x540 Dual Port 10Gb BT + i350 DP 1Gb BT NDC: A quad-port rack NDC with 2 ports x 1GbE + 2 ports x 10GBASE-T based on the Intel I350 and x540 chipsets.
  • Intel Ethernet i350 Quad Port 1GbE NDC: A quad-port rack NDC with 4 ports x 1GbE based on the Intel I350 chipset.
    An Intel 2x1Gb + 2x10Gb Base-T rack NDC, as shown in the following figure, offers two types of interconnects to meet various connectivity needs.

Rack 2x1Gb+ 2x10Gb BT NDC

Figure3: Rack 2x1Gb+ 2x10Gb BT NDC

  • Broadcom 57800S 2x1Gb+2x10Gb SFP+ NDC: A quad-port rack NDC with 2 ports x 1GbE + 2 ports x 10G SFP+ based on the Broadcom 57800S chipset. Just shown as the following figure.
  • Broadcom 5720 4x1Gb Base-T NDC: A quad-port rack NDC with 4 ports of 1GbE based on the Broadcom 5720 chipset.

Rack 2x1Gb+ 2x10Gb SFP+ NDC

Figure4: Rack 2x1Gb+ 2x10Gb SFP+ NDC

How to Choose the Optical Cables and Modules for Broadcom or Intel Network Adapter?

Just take Broadcom 57800S 2x1Gb+2x10Gb SFP+ NDC for example. A Broadcom 2 x 1G + 2 x 10G SFP+ NDC provides two 1000BASE-T ports and two 10G SFP+ ports as shown in Figure 6. We can plug two Dell compatible SFP transceivers into the two 1G ports on the Broadcom NDC respectively to achieve 1G network connection. Likewise, we can also connect Dell compatible SFP+ transceiver such as 10Gb Base SR connector to the 10G port on the Broadcom card for making 10G data transferring. Besides, we can also use Direct Attach Cable (DAC) to achieve 10G network connectivity, such as multimode 10Gb fiber optic cable, Dell 10G SFP+ DAC cable. DAC cables provides a cost-effective solution for very short transmission while 10G optical modules are more suitable for data transferring over long distance.

Broadcom 57800S NDC with Dell SFP+ module

Figure5: Broadcom 57800S NDC with Dell SFP+ module


As technology advanced and 10Gb Ethernet became more prevalent in the data center, there must be a prosperous market ahead for blade servers and rack servers. SFP+ modules and Direct Copper Attached is the current preference for 10GbE connectivity of rack servers. Boardcom and Intel are both famous vendors for providing NDCs for Dell PowerEdge Server, you can select a proper one for your server according to your port needs.


Cisco 3650 Vs. 3850 Catalyst Switches

Cisco Catalyst 3650 and 3850 series switches are enterprise class stackable switches. Cisco Catalyst 3650 series was unveiled in 2013 which designed to converge wired and wireless networking. Just in the same year, Cisco launched its first flagship Catalyst 3850 series switches . That provide a converged wired and wireless platform as well. With they have many things in common, many people confused about them and found it hard to decide which one to buy. This article would introduce Cisco 3650 and 3850 series switch as well as their main differences.

Cisco Catalyst 3650 Series Switch

There are 21 Cisco 3650 Series Switch models in total. All Cisco Catalyst 3650 Series Switches have fixed, built-in uplink ports. The Catalyst 3650 features line rate 24 and 48 Gigabit Ethernet ports and an integrated wireless controller. It can be stacked in groups of nine switches for support of up to 25 access points and 1,000 clients at 40Gbps. The uplink ports of all switch models can be divided into the following five types:

  • Four Gigabit Ethernet with Small Form-Factor Pluggable (SFP)
  • Two 10 Gigabit Ethernet with SFP+ and two 10 Gigabit Ethernet with SFP or four Gigabit Ethernet with SFP
  • Four 10 Gigabit Ethernet with SFP+ or four Gigabit Ethernet with SFP
  • Eight 10 Gigabit Ethernet with SFP+ or eight Gigabit Ethernet with SFP
  • Two 40 Gigabit Ethernet with QSFP+

Cisco Catalyst 3650 Series Switch

Figure1: Cisco 3650 48Port PoE+ Switch

Cisco Catalyst 3850 Series Switches

The Cisco Catalyst 3850 Series Switches are modular and field-replaceable network modules, which has RJ45 and fiber-based downlink interfaces, and redundant fans and power supplies. It fully supports IEEE 802.3 at Power over Ethernet Plus (PoE+). Compared with 3650 Series Switches, they have less switch modules—14 switch modules. Besides, they are stackable 3K switches, which can fully meet your requirement for evolving business. Some main features of Cisco 3850 are just listed in the following:

  • Functionality added traffic aggregation. All Unified Access intelligent services can be persevered and delivered across the entire network from the access layer to the aggregation layer.
  • Long distance transmission. The 3850 switches can be used to connect branch offices and small campus buildings. The fiber connections can support up to 80 km of physical distance.


Figure2: Cisco 3850 PoE+ Switch

  • High compatibility. The 3850 switches support a variety of optical modules and connectors, therefore allowing many deployment options.
  • Enhanced security. It comes with native TrustSec functionality such as Security Group Tag (SGT) so that you have it enabled everywhere—from access to aggregation. Also, fiber connections provide strong physical security.

The flexibility of the 3850s is greater than the 3650s, because they are stacking and optional stacking switches respectively. The 3850s can do power stacking, that is an exclusive feature compared to the 3650s. Stacking is built in, and the short stacking cables are included. Larger stacks might require the longer stacking cables, that is a potential downside.

3650s can do stacking as well, but you need to buy the modules separately (and they are like $1,000 a pop list price), which adds up quickly.


The 3850s is the more powerful device than the 3650s, which featured as the great horsepower. Besides, as we mentioned before, the 3850s can do power stacking while the 3650s cannot.


Compared with the 3650s series switches, the 3850s series switches have higher capacity. The maximum switching capacity of the 3850s switches can arrive at 1280 Gbps on 48-port 10 Gigabit Ethernet SFP+ model while the 3650s switches at 472 Gbps on 48-port Multigigabit models.

Cisco 3650 24Port PoE+ switch

Figure3: Cisco 3650 24Port PoE+ switch


There are only slight differences between the two switches in terms of price. Just take the 24-port switches of two different series for example, you can see the differences more clearly by clicking the following link:






This article chiefly discussed the Cisco Catalyst 3650 and 3850 series switches as well as their differences. How to choose? They are both great switches. It depends on what you really want to do and what you want out of your switches, and what your budget is. Besides, if you are looking for the compatible optical modules for those two switches, you can take FS.COM a try. We offer large and in-stock Cisco SFP, SFP+, 40G QSFP+ and 100G QSFP28 optical transceivers with high quality but low cost. For more details, please visit www.fs.com.

Unifi Switch Vs. EdgeSwitch

Recently, Ubiquiti Network Switch is of prevalence for building and expanding home network. EdgeSwitch and Unifi Switch are two main switch series of the Ubiquiti Network Switch. For years, the EdgeSwitch and Unifi Switch are featured as cost-effective, robust performance, and this is why many people have special favour on them. For they both a good choice for growing networks, it is necessary to make clear their differences and decide which one to choose. In this article, we will mainly introduce the EdgeSwitch and Unifi Switch, similarities and differences as well as compatible SFP transceivers for them.


Figure1: This picture shows Unifi Switch US-8-150W

Introduction to Unifi Switch

The Unifi Switches provide 8, 16, 24, or 48 PoE Gigabit Ethernet ports to satisfy different requirement for expanding Gigabit Ethernet network and making your network cabling looks neat. They support IEEE 802.3af and IEEE 802.3at. And the operation is rather easy, you can directly connect your switch to a storage server through two SFP ports on each switch. The transmission rate can be up to 1 Gbps. For longer distance and higher bandwidth, you can use Unifi Switch with 48-port which additional added two more SFP+ port. The following picture shows a basic parameter of all the Unifi Switches models.

Chart1 Unifi Switch

Information About EdgeSwitch

As same as Unifi Switch, the EdgeSwitch have the same PoE Gigabit Ethernet ports and IEEE protocols. The most distinctive feature of Edgeswitch is that offers an extensive suite of advanced Layer-2 switching features and protocols, and also provides Layer-3 routing capability. There are 6 EdgeSwitch models, the accurate ports’ number are clearly shown in the below chart. You can use ES-8-150W, ES-16-150W and ES-24-250W as well as ES-24-500W switch models to achieve 1G Ethernet network connectivity. For SFP+ transceivers, you can choose ES-48-500W, ES-48-750W to arrive 10 Gbps connection.



Both Unifi Switch and EdgeSwitch have 8, 16, 24, or 48 PoE Gigabit Ethernet ports.

—Switch models

The two switch basically share the identical switch type (switch ports and Watts), the only difference lies in the EdgeSwitch does not have one with 8 ports for 60W.


The Unifi Switch and EdgeSwitch both support IEEE 802.3af and IEEE 802.3at.

—Supporting Gigabit Ethernet

They are both support 1G and 10G Ethernet connection and have both SFP and SFP+ ports.


The EdgeSwitch is black while the Unifi Switch is silver.

EdgeSwitch and Unifi Switch


The Unifi Switch can only be managed through the UniFi controller while the EdgeSwitch can only be managed through it’s CLI or web interface.

—Routing protocols

The EdgeSwitches only support static routing, and there are no routing protocols implemented while Unifi Switches don’t support routing at all.

FS.COM’s Compatible SFP Module for Unifi and EdgeSwitch:

Multi-mode and singlemode SFP models are available to Unifi and Edge switch. FS.COM is a leading manufacturer and supplier of fiber optic subsystems, components and solutions. Our optical modules are well known as the superior quality and high compatibility. Besides, all of our products are tested and 100% compatible to the major brands, such as Cisco, Juniper, Brocade, Arista, etc. You can rest assured to use them. For this Unifi and Edge switch, we offer the following compatible SFP module:

1000Base-LX: SFP1G-LX-31 1310nm (SingleMode SFPs).

1000Base-SX: SFP-1G85-5M (multi-mode).

1000Base-T: SFP-GB-GE-T Module.

FS's SFP+ transceiver


Ubiquiti Network Switch seems to be an irresistible trend for home network connectivity. Through this passage, we learned that Unifi Switch and EdgeSwitch are different in color, management and routing protocols. If you are looking for compatible SFP transceivers for those two kinds of switch, you can take FS.COM a try. In addition to SFP transceivers, we still offer many other optical products, such as patch cables, SFP+, QSFP and QSFP28 optical modules, network cables, switches, etc. If you are interested, you can visit www.fs.com.

Ubiquiti US-8-150W POE Switch—An Economic Choice for Home Ethernet Connection

It is universally acknowledged that price is one of the key factors when we buy something. We may heave a sigh of the soaring cost of the switches of the major brands on the current market, such as Cisco, Arista, Juniper…However, that is not a good deal for home and some small enterprises to make Ethernet network connectivity. Ubiquiti POE switches provide a perfect solution for this deadlock. This article would provide the detailed information about Ubiquiti US-8-150W POE switch—its compatible Ethernet cables and SFP modules as well as connection solution.

Why Choose Ubiquiti US-8-150W POE Switch?

Nowadays, a lot of families choose Unifi to make Ethernet connection and Ubiquiti sells Unifi-compatible POE switches. Lately, the company has just launched its line of Unifi switches with two more models better suited for home use: the 16-port US-16-150W and the fanless 8-port US-8-150W. They are silent and unobtrusive. The highlight lies in their price, they only cost $299 and $199 respectively. Moreover, they integrate into the same Unifi Web interface as the APs and the Ubiquiti router/gateway. Compared to the Ubiquiti 16-port US-16-150W switch, the Ubiquiti US-8-150W POE switch is more suitable for home use in view of its unique design and function, the detailed information would be provided in the following paragraph.


About Ubiquiti US-8-150W POE Switch

The Ubiquiti US-8-150W POE Switch delivers quiet yet powerful performance with its 10 independent switching ports. It has 8 RJ45 ports which support 10/100/1000 Ethernet connections and PoE. Two hot-swappable SFP ports support 1 Gbps connections. The switch shares a total of 150W PoE, eight Gigabit Ethernet ports offer 802.3af/at PoE+ or 24V passive PoE, and two SFP ports offer optical connectivity. You can see it more clearly in the following figure.

The front panel of Ubiquiti US-8-150W

Compatible Ethernet Cable for Ubiquiti US-8-150W

As we mentioned above, the eight RJ45 ports support 10/100/1000 Ethernet connection, so the Cat5e, Cat6 and Cat6a Ethernet cable all can be deployed. As for the most appropriate one, that depends on your actual transmission distance demand. The maximum transmission distance of each Ethernet cable is shown in the below chart. You can select a proper one for yourself based on it.

chart Ethernet cables and their maximum transmission distance

FS.COM’s Compatible SFP Modules for Ubiquiti US-8-150W:

Multi-mode and single mode SFP models are available to Ubiquiti US-8-150W. FS.COM (Fiberstore) is a leading manufacturer and supplier of fiber optic subsystems, components and solutions. We are doing business withe many well-known corporations like CloudFlare, Apple, Avago, EXFO, etc. Our optical modules are well known as the superior quality and high compatibility. Besides, all of our products are tested and 100% compatible to the major brands, such as Cisco, Juniper, Brocade, Arista, etc. You can rest assured to use them. For this Ubiquiti US-8-150W switch, we offer the following compatible SFP modules:

1000Base-LX: SFP1G-LX-31 1310nm (SingleMode SFPs).
1000Base-SX: SFP-1G85-5M (multi-mode).
1000Base-T: SFP-GB-GE-T Module.

Compatible FS.COM's SFP module for Ubiquiti US-8-150W

This figure shows compatible FS.COM’s SFP module for Ubiquiti switch.

How to Connect?

Before you begin, please make sure you have the following at hand.

1. Three ethernet cables
2. One micro-USB power cable (5V, minimum 1A as DC output).
3. Your existing router (with at least 3 available LAN ports).
4. An Unifi Switch 8-150W switch
5. UniFi Access Point (UAP) and the Cloud Key (CK) boxes


StepⅠ:The devices will be connected in the following manner:
Your functioning router’s LAN port > US8 (any port) > UAP + CK + Computer (all three connected to the UniFi Switch–this means your router only needs one available LAN port).

Unifi Switch 8-150W switch connection_

StepⅡ:No power injector will be needed for the UAP once it has been plugged into the UniFi Switch 8. The US-8 will provide the necessary power for the Access Point.

Step Ⅲ:The Cloud Key does not require a USB power cable or adapter–it will be powered via the US-8, just as the UAP.

Step Ⅳ:The UniFi Switch needs to be adopted by the controller, and have firmware upgraded in the same way as the UAP.


Through the above descriptions, we may acquire some basic information about the Ubiquiti US-8-150W POE switch. It does an economic choice for 1GbE SFP switch, especially for the home Ethernet connectivity. If you need the compatible Ethernet cables and SFP modules, you can take FS.COM a try. In addition to the above products, we also offer many other fiber optic products with high quality but low cost. If you are interested, please feel free to contact us.

OM5 Multimode Fiber Has Been Online

Multimode fiber optic cable has been widely used in our daily life for its cost-effective, low power consumption and etc. The OM family recently was added a new member, called as OM5. Different from the previous OM1 to OM4, OM5 is a wideband multimode fiber, which will support short wavelength division multiplexing (SWDM). This article would provide general information about OM5 and differences between OM5 and OM3, OM4.

Information About OM5

As early as 2016, Commonscope introduced their LazrSPEED Wideband Multimode Fiber (WBMMF), and the ISO/IEC decided the nomenclature for WBMMF is OM5 in October 2016. Later, wideband OM5 fiber was defined by IEEE 802.3bs, which refers as a multimode 400Gb/s link, 400GBASE-SR16, using 16 transmit and 16 receive fibers (32 fibers total) over a link distance of 100 m. Currently it shows that OM5 wider operating window offers no immediate advantages compared with OM4 fiber. But using OM5 will make the network ready for future use of SWDM technology.


At present, several major brands like Cisco, FIT, Finisar have been devoted to develop and research multimode WDM solutions that solve customer needs. And it seems that Finisar is a pioneer at this point. So far, Finisar has announced two products that offer SWDM using NRZ technology. One product is a 100G-SWDM4 transceiver. This transmits over four wavelengths at 25Gb/s per wavelength for an aggregated 100Gb/s. This product will support link distances of 70 m on OM3, 100 m on OM4 and 150 m on OM5. Moreover, OM5 does not support any existing optical transceiver but 100G-SWDM4 transceiver.

Differences Between OM5 and OM3, OM4

The most distinctive highlight of OM5 fiber is that it supports at least four short WDM channels simultaneously while OM3 and OM4 fiber only support one wavelength at a time. OM5 allows for 4 times the bandwidth than legacy OM4. That means the same amount of bandwidth dedicated to 8 fibers on OM4 can now transmit just 2 strands. Utilizing SWDM, you can transmit over 850 nm, 880 nm, 910 nm, and 940 nm simultaneously.



Attenuation testing at 850 nm and 1300 nm are sufficient to verify that the OM5 fiber meets 953 nm attenuation requirements. That is to say, the working wavelength of OM5 is between 850 nm and 953 nm while OM3 and OM4 between 850 nm and 1310 nm. It is common sense that the shorter the wave range, the less the attenuation. Thus, OM5 has right advantage on this aspect.

—Transmission distance

Based on 10 Gigabit Ethernet, the transmission distance of OM3 and OM4 can reach 300 m and 400 m respectively. OM5 fiber optical cable has the same maximum transmission distance as OM4.

—Jacket color

As earlier in March this year, the TIA started TIA-598-D-2 to determine lime as the jacket color for cabled WBMMF (TIA-492AAE, OM5). And now, lime is the new aqua, which stands for the standard jacket color of OM3 and OM4.



Although it seems that OM5 has not the absolute advantage over OM4, but it can meet the requirement for a higher bandwidth in a long term. Selecting OM5 MMF will give you the flexibility in the future to easily add bandwidth without adding more fiber. Estimates claim that there will be 30 billion connected devices next year. Time would tell the OM5 multimode fiber will be the most cost-effective short-reach solution in the enterprise and data center on short-reach market.

How to Choose the Right 100G QSFP28 Optical Transceiver?

As an advanced manufacturing technology, QSFP28 optical transceivers have been highly favored by a large number of Ethernet users. We use large scale deployment and application of 100G optical transceivers in data center, Local Area Network(LAN), Wide Area Network(WAN), Ethernet switches and so on. Based on the unique low cost optical design package, we fully enjoy the great value crated by the new generation of 100G QSFP28 technology. There are many products with QSFP28 form factor like SR4, LR4, ER4, CWDM4, PSM4…

Facing so many different QSFP28 transceivers, we may be at a loss to choose an appropriate one for ourselves. At some extend, it really depends on our real demand. Due to limited space, we would mainly guide you how to choose a right one for your application from the perspective of transmission distance. Hope this article would help.

Transmission Distance

Different applications have given requirements for transmission distance, and the specific conditions and feasible measures will be fully covered in the following text.

Transmission Distance Is 100 m or Under 100 m

QSFP28 SR4 is highly recommended. The QSFP28 SR4 supports links of 70 m (OM3) and 100m (OM4) over multimode fiber with MPO connectors. It offers 4 independent transmit and receive channels, each capable of 25Gbps operation for an aggregated data rate of 100 Gbps. The QSFP28 SR4 modules are ideal for rack to rack connections in the data center and short reach telecom applications.

Transmission Distance Is Over 100 m But Under 10 km

QSFP28 LR4 is preferred. The QSFP28 LR4 is a fully integrated 4 × 25Gbit/s optical transceiver module, which supports distance up to 10 km. For long span 100GbE deployment, such a connectivity between two buildings, QSFP28 LR4 with duplex LC single-mode fiber cable is the perfect option.


Transmission Distance Exceeds 10 km

QSFP28 ER4 is ideal for very long transmission distance. The QSFP28 ER4 optical transceiver provides superior performance for 100G Ethernet applications up to 30 km links. The 100G QSFP28 ER4 module converts 4 input channels of 25Gb/s electrical data to 4 channels of LAN WDM optical signals and then multiplexes them into a single channel for 100Gb/s optical transmission.

Note: When an optic says “10 km”, this is only a guideline. Actual distances can be significantly better or worse. It depends on your actual usages at large extend, including regular cleaning and maintenance.

How to Choose Based on the Same Transmission Distance?

We discussed the optimal options according different transmission distances, but it seems that it is hard to make a decision when the transmission distance is identical. QSFP28 CWDM4 and QSFP28 PSM4 are designed to meet the requirement for intermediate or mid-reaches for datacenter applications (500 m to 2 km). They both use WDM and parallel single mode fiber technologies and support transmission distance up to 2 km.


The CWDM4 provides a 100G Ethernet high-speed link with a maximum transmission distance of 2 km, which interfaces with LC duplex connectors. The CWDM4 module uses Mux/Demux technologies with 4 lanes of 25Gbps optically multiplexed onto and demultiplexed from duplex single-mode fiber.



PSM4 does not need a MUX/DEMUX for each laser but it does need either a directly modulated DFB laser (DML) or an external modulator for each fiber. With an MTP interface, PSM4 modules can bus 100Gb/s point-to-point over 2 km or can be broken out into dual 50Gb/s or quad 25Gb/s links for linking to servers, storage and other subsystems.

How to Choose?

From the aspect of an inner transceiver module structure, PSM4 can be more cost effective because of its lower component costs. However, from an infrastructure viewpoint, PSM4 would be more expensive when the link distance is long, mainly because PSM4 uses 8 optical single-mode fibers while CWDMs uses only 2 optical single-mode fibers.

Where Can Buy QSFP28 Transceivers at Low Cost ?

You may dizzy about the mess online shopping websites about fiber optic, and it is hard to find one online store that provides fiber optic products with high quality but low cost. Under this condition, you can try FS.COM which is an online shopping store about fiber optic communication. Our products has been deployed in data center and cloud computing applications all over the world.

For the mentioned 100G QSFP28 SR4, we have a big slump on it recently. Buying it now only needs $269, which is tripled on other online shopping stores. Here, we made a comparison between FS.COM and Amazon.com on Cisco QSFP-100G-SR4-S price. You can see it clearly by clicking the following link. Besides, all of our optical transceivers all 100% tested and fully compatible to many major brands such as Cisco, Juniper, Arista…

100G QSFP28 SR4

Cisco QSFP-100G-SR4-S at FS.COM: http://www.fs.com/products/48354.html

Cisco QSFP-100G-SR4-S at Amazon.com: https://www.amazon.com/Third-Party-100GBASE-SR4-QSFP28-Cisco/dp/B01H0T2CIG/ref=sr_1_1?ie=UTF8&qid=1498731653&sr=8-1&keywords=Cisco+100G+QSFP28+SR4


According to the above provided information and suggestion, you can choose the right QSFP28 transceiver for your application. FS.COM provides 100G QSFP28 modules for short reach, long reach and intermediate applications. For more details, please visit www.FS.COM.


An overview on Cisco Catalyst 3750-X Series Switch

In the later year of 2011, Cisco launched 3750 Series switch, with a purpose to improve LAN operating efficiency and resiliency for stackable switches. Cisco Catalyst 3750-X Series is one series of Cisco 3750 Series, which featured as high availability, scalability, security, energy efficiency, and ease of operation. The detailed information about Cisco Catalyst 3750-X Series switch would be provided in this article. In addition, we will guide you to plug your optical modules into this switch, all the installation and removing procedures as well as cautions are fully covered in the following passage.

Overview on Cisco Catalyst 3750-X Series switch

Cisco Catalyst 3750-X Series switch are 12-port and 24-port Gigabit Ethernet Small Form-Factor Pluggable (SFP) switches. You can see it more clearly in the following figure. Different from the traditional switch design, they additionally added some other functions, such as four optional network modules, redundant power supplies, and so on. Cisco Catalyst 3750-X Series switch are enterprise-class stackable switches and can be used for aggregation solutions in small core, midmarket, or branch office environments. The features and benefits of them are just listed in the following:


Figure1: Cisco Catalyst 3750-X Series switch with 12-port and 24-port

  • Four optional uplink network modules with Gigabit Ethernet or 10 Gigabit Ethernet
  • Dual redundant, modular power supplies and fans.
  • MACsec hardware-based encryption
  • Flexible NetFlow and switch-to-switch hardware encryption with the uplink service module
  • Enhanced Cisco EnergyWise for operational cost optimization
  • Ipv4 and IPv6 routing, multicast routing, advanced quality of service (QoS), and security features in hardware
  • Enhanced limited lifetime warranty (LLW) withe nest business day (NBD) advance hardware replacement and 90-day access to Cisco Technical Assistance Center (TAC) support
  • USB Type-A and type-B ports for storage and console respectively and an out-of-band Ethernet management port
Installing an SFP Module in the Switch

As we mentioned before, the Cisco Catalyst 3750-X Series switch are 12-port or 24-port SFP switches. That is to say, on this kind of switch, only SFP modules supported. The SFP modules provide copper or fiber-optic connections to other devices. These transceiver modules are filed-replaceable, providing the uplink interfaces when installed in an SFP module slot. The SFP modules have LC connectors for fiber-optic connection or RJ-45 connectors for copper connections. Before installing SFP module in this switch, please remember use only Cisco SFP modules on the switch.

Installation procedures:

Step1: Attach an ESD wrist strap to yourself and a properly grounded point on the chassis or the rack.

Step2: Remove the SFP transceiver from its protective packaging.

Step3: Check the label on the SFP transceiver body to verify that you have the correct model for your network.

Step 4: Remove the optical bore dust plug and set it aside.

Step 5: If the SFP module has a bale-clasp latch, move it to the open, unlocked position.

Installing Cisco SFP module

Figure2: Installing Cisco SFP module to the switch

Step 6: Align the SFP transceiver in front of the transceiver’s socket opening and carefully slide the SFP transceiver into the socket until the transceiver makes contact with the socket electrical connector.

Step7: Press firmly on the front of the SFP transceiver with your thumb to fully seat the transceiver in the module’s transceiver socket (see the below figure) on the Cisco Catalyst 3750-X Series switch.

Caution: If the latch is not fully engaged, you might accidentally disconnect the SFP transceiver.

Step9: For optical SFP transceiver, reinstall the dust plug into the SFP transceivers optical bore until you are ready to attach the network interface cable. Do not remove the dust plug until you are ready to attach the network interface cable.

Removing SFP modules

Step1: Attach an ESD-preventive wrist strap to your wrist and to a bare metal surface.

Step2: Disconnect the cable from the SFP module. For reattachment, note which cable connector plug is send (TX) and which is receive (RX).

Step3: Insert a dust plug into the optical ports of the SFP module to keep the optical interfaces clean.

Step4:If the module has a bale-clasp latch, pull the bale out and down to eject the module. If you cannot use your finger to open the latch, use a small, flat-blade screwdriver or other long, narrow instrument to open it.

Step5: Grasp the SFP module, and carefully remove it from the slot.

Removing Cisco SFP module

Figure3: Removing Cisco SFP module from the switch

Step6: Place the SFP module in an antistatic bag or other protective environment.


The Cisco Catalyst 3750-X Series switch provides high scalability, ease of management, and investment protection for evolving business needs. The installation and removing of SFP optical modules to the Cisco Catalyst 3750-X Series switch are easy operations. If you are looking for Cisco SFP modules for connection with Cisco Catalyst 3750-X Series switch with reasonable price and high quality, FS.COM would be a nice choice. Here, we offer large and in-stock SFP modules, they are 100% tested and fully compatible with Cisco 3750-X series switches. If you are interested with our products, please feel free to contact us.

Decoding 25G Ethernet And Its Optics

Most us of us may quite familiar with 10G, 40G and 100G Ethernet network, but we know little about 25G Ethernet, or even never heard about it. In the race of 10G, 40G and 100G Ethernet, it seems that 25G Ethernet lagged far behind. However, it is a good choice for network connectivity indeed. So what is 25G Ethernet and its benefits? And what about its cables and optical modules? The detailed information about 25G Ethernet would be provided in this article.

Overview on 25G Ethernet

Researched and developed by IEEE group, 25G Gigabit Ethernet is a standard for Ethernet connectivity. Compared with 10G, 40G and 100G Ethernet, 25G and 50G Ethernet were the latest developed Ethernet specification. 25G Ethernet Consortium was formed in July 2014 to support the specification of single-lane 25G Ethernet. It is an open organization to all third parties who wish to participate as members to enable the transmission of Ethernet frames at 25 or 50 Gigabit per seconds (Gbps) and to promote the standardization and improvement of the interfaces for applicable products.

25G Ethernet Specification

Based on single lane 25 Gb/s technology, the Consortium standard provides specifications for implementation, enabling Ethernet users to deploy cost effective Ethernet technologies. It is a technology that aimed at using (a) one 25 Gb/s lane to connect a single MAC operating at 25 GB/s by means of a Clause 49 PCS. The following figure shows how 25 Gb/s ports can be enabled.

25G Single Lane

Figure1: 25Gb/s SerDes Single Lane

For the configurations shown in Figure 1, 25Gb/s interfaces represent themselves as networking ports. They can auto-negotiate link speed by proprietary bit locations in extended capabilities registers.

Features and advantages of 25G Ethernet
  • Technology
    25G Ethernet technology is designed for application and infrastructure efficiency that results in a better data center ROI.
  • Robustness and reliability
    The 25G Ethernet technology is robust and reliable, and the products of Ethernet 25G are deigned to the highest standards and built to last. Weakness in one area can cascade and cause challenges that impact the entire system design and limit product reliability. The consequences would be too ghastly to contemplate.
  • Performance
    Industry analysts are predicting that 25GbE Ethernet will have the fastest adoption ramp ever for a new Ethernet technology. To make this forecast a reality requires not only 25 GbE technology that is both manufacturable and offers better features and capabilities, but also provides a true performance advantage.
  • Ease of adoption
    The IEEE group and 25G Ethernet Consortium have worked hard to ensure that 25G Ethernet offers a seamless upgrade to 10G Ethernet environments, with backwards compatibility that use the same 10GbE LC fiber cabling that has already been deployed in the data center.
  • Price
    Although 25GbE Ethernet is slightly more expensive than the 10GbE pricing, it still delivers a reasonable price. In fact the 25GbE pricing is very competitive, with only a 30% to 40% premium over 10GbE, and this premium is expected to come down over time. Overall, 25G Ethernet still offers a cost-effective solution for network connectivity.
25G SFP28 Optics

In general, there are three kinds of SFP28 optics, 25G SFP28 AOC and DAC cables as well as 25G SFP28 transceivers.

25G SFP28 AOC and DAC cable

The 25G SFP28 active optical cable is designed to overcome the bandwidth limitation of traditional copper cable so as to meet the high bandwidth in data center. It is hot pluggable and preterminated twin axial cable/fiber cable. The transmission distance can be 70 m by active optical cable with OM3 fiber. It is applicable to 25G and 10G Ethernet, data center and in-rack connection. For SFP28 DAC cable, there are two types: 25G SFP28 to SFP28 DAC and 100G QSFP28 to four SFP28 breakout DAC. These copper cables provide a cost-effective solution for connection with Top of Rack switches.


Figure2: 25G SFP28 Active Optical Cable

25G SFP28 transceivers

Basically, there are two kinds of 25G SFP28 transceiver, 25G SFP28 SR and 25G SFP28 LR optical transceiver. The 25G SFP28 SR designed to transfer data over short distance while the 25G SFP28 LR transceiver set for long distance transmission. The maximum transmission length of 25G SFP28 SR is 100 m over 50μm multimode optical fiber. The transmission distance of 25G SFP28 LR optical transceiver can be up to 10 km over single-mode fiber. Both the transceivers can be applied to data center, 10G&25G Ethernet, high-speed storage area networks and in-rack connection.


Figure3: 25G SFP28 Transceiver


25G Ethernet is taking off fast. It has a handful of very powerful data center and cloud vendors and suppliers-Google, Microsoft, Broadcom, Arista, Mellanox and Cisco. The 25G technology already exists in 100G will drive better cost efficiencies than 40G as well, saving cloud providers and enterprise data centers capital and operating expense. FS.COM provides large and in-stock 25G SFP+ cables and 25G SFP SR transceiver with high quality but low cost. If you are interested with our products, please feel free to contact us.