Focus On Fiber Optic Link Loss

We know that, no natter what component you use, there must insertion loss in your fiber optic cabling. Therefore, in order to make your fiber optic cabling system perform at high level, calculating the amount of insertion loss before cable plant is necessary. This article will focus on fiber optic link loss.

Overview of Link Loss And Link Loss Budget

The link loss and link loss budget are measured in dB. Link loss is the total insertion loss of all optical components in an optical network. While link loss budget is the amount of loss that a cable plant should have. It is calculated by adding the average losses of all the components used in the cable plant to get the total estimated end-to-end loss. The link loss budget has two important functions: during the design stage to ensure the cabling being designed will work with the links intended to be used over it and; after installation, comparing the calculated link loss to test results to ensure the cable plant is installed properly.

How to Calculate Link Loss?

Usually, the loss of four parts need to be calculated: mated pair connector loss, fiber optic splicing loss, fiber optic cable loss and other loss.

link loss calculation

  • Mated Pair Connector—EIA/TIA 568 standard allows 0.75 max per connector

Connector or “connection” loss is the total loss of the mated pair connectors. It’s standard to assume a 0.3 dB loss for most ultras polished connectors. In order to measure the loss of the connectors, you must mate them with similar connectors, or you are likely to experience different losses. Also, a high quality connector is required when testing matted pairs.

  • Fiber Optic Splicing—EIA/TIA 568 max loss is 0.3 dB per splice

According to the Fiber Optic Association (FOA), multimode splices are commonly made using mechanical splices. Best construction practices dictate that even with multimode fiber fusion splicing is ideal. Both forms of splicing generally result in satisfactory results, however fusion splicing proves to be more reliable in adverse surroundings. Single mode fibers that have been fusion spliced will typically have less than 0.10 dB loss. A good average for a skilled installer is generally around 0.05 dB loss.

  • Fiber Optic Cable

EIA/TIA 568 spec for multimode fiber is 3.5 dB/ km at 850 nm and 1 .5 dB/km at 1310 nm. This specification translates into a loss of approximately 0.1 dB per 100 feet for 850 nm, 0.046. dB per 100 feet for 1300 nm. For example, 300 ft multimode fiber optic cable at 850 nm would approximately equal 0.3 dB loss. While for single mode fiber, the loss is 0.5 dB per km at 1310 nm, 0.4 dB per km for 1550 nm.

  • Other Loss—Passive Components and Margin

Don’t forget to count any other passive components you are using in your network. For example, if you are using splitters or filters, add the insertion loss for those components. In addition, it is recommended to add margin to your link loss calculation to adjust for any unforeseen losses. The amount may vary by designer or application but typically 2-3 dB will allow for sufficient headroom in you network link loss calculation.


The fiber optic link loss calculation and analysis are vital in cable plant. After the cable plant is installed, the calculated loss values are compared with the test results to ensure the link can operate properly. Besides, to reduce the link loss, high quality components are required. Quality is everything when gigabit and higher speeds are required. FS.COM provides high quality fiber optic connector, fiber optic cable and fiber optic transceiver at reasonable price. Also, test tools can be found here, such as light source and power meter. For more details, you can visit our site.


A Closer Look at HP ProCurve 2910al-24G Switch (J9145A)

Today, big data centers are upgraded from 10G to 40G or 100G, and some small homelabs migrate from 1G to 10G. For some small business data center, 24 port switch is enough. The switches produced by HP are popular with many data center designers for the high quality and low price. The HP ProCurve 2910al-24G Switch (J9145A) is highly recommended in many forums. This article will guide you to have a closer look at HP ProCurve 2910al-24G Switch (J9145A) switch.


The HP ProCurve 2910al-24G switch (J9145A) is a 24 port switch that can be used to build high-performance switched network. It offers low latency for high-speed networking. For port configuration, it has twenty 10/100/1000 ports, four dual-personality ports, one RJ45 serial console port and four 10G ports. The HP ProCurve 2910al-24G switch can provide the most flexible and easy-to-deploy uplinks in its class. It can be deployed at enterprise edge and remote branch offices, converged networks, and data center top of rack.

HP ProCurve 2910al-24G Switch (J9145A)

Applications of HP ProCurve 2910al-24G Switch

This part will give a detailed introduction to the network ports on HP ProCurve 2910al-24G switch and cabling solutions for the switch.

Ports on HP ProCurve 2910al-24G Switch
  • Twenty 10/100/1000 ports: All these ports have the “Auto MDIX” feature, which means you can use either straight-through or crossover twisted-pair cables to connect any network devices to the switch.
  • Four dual-personality ports: Each port can be used as either an RJ45 10/100/1000 port or as a mini-GBIC slot for use with mini-GBIC transceivers. By default, the RJ45 connectors are enabled. If a mini-GBIC is installed in a slot, it is enabled and the associated RJ45 connector is disabled and cannot be used. If the mini-GBIC is removed, the associated RJ45 port is automatically re-enabled.
  • Four 10G ports: These ports provide connectivity for 10G speed though either copper or fiber optic media.
Cabling Solution

Since HP ProCurve 2910al-24G switch has 10/100/1000 ports, it can be used for 1G to 1G connection. As shown in the following figure, two 1000BASE-SX SFP transceiver modules are respectively plugged into 1G ports on two HP ProCurve 2910al-24G switches. Then these two 1000BASE-SX SFP transceiver modules are connected via a LC multimode fiber optic cable.

HP ProCurve 2910al-24G Switch (J9145A) for 1G connection

Designed with 10G ports, HP ProCurve 2910al-24G switch can realize 10G to 10G connection just like the above 1G connection. Just replace the 1000BASE-SX SFP transceiver module with 10GBASE-SR SFP+ transceiver. Besides, you can also accomplish 10G to 10 connection by using a 10G SFP+ to SFP+ DAC twinax cable. The following figure shows the cabling solution for you.

HP ProCurve 2910al-24G Switch (J9145A) for 10G connection


The HP ProCurve 2910al-24G switch (J9145A) is a high-performance Gigabit Ethernet switch. It is a good selection for small business network deployment. If you need compatible fiber optic transceiver and fiber optic cable for HP ProCurve 2910al-24G switch, you can have a look at FS.COM. The following table shows some compatible optical components. For more details, you can visit our site.

FS Compatible Optical Components

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Set Up 10G Home Network

Nowadays, nobody would deny the importance of the network. It has become an inseparable part of our daily life. As it developed, people’s demand for bandwidth is increasing. And 10G network is widely applied in small and middle sized business. In addition, 10G home network can be also commonly found. This article will share some tips to set up 10G home network.

Consideration Before Setting Up 10G Home Network

Why do you need 10G network? It is not difficult to find that almost everything nowadays rely on a fast and reliable network, which leads to tremendous traffic and applications running on the network. It is necessary to upgrade your home network to support the growing of your business. Setting up 10G home network avoids network congestion at busy times while improves your productivity.

What do you want from 10G home network? Before you start to set up the network, better planning is needed. You should ask yourself a few questions, such as how many computers, printers and other peripherals will connect to your network? How much wireless coverage will you need at your location? What type of mobile devices will need access to your network?

Needs for 10G Home Network
10G Switch

To build a 10G home network, several components are required: 10G core switch, access switch with 10G uplink, and 10G network interface cards for servers and storage devices. The past few years had witness the price dropping of 10G network switch. For example, the cost of Ubiquiti Unifi and Edgeswitch switch are only $200. You can also find many 10G switch under $550, such as FS.COM 10G network switch S3800-48T4S only costs $480 by offering 48 100/1000Base-T and 4 10GE SFP+ ports.

10G switch
10G Cabling

There are two cabling ways for 10G home network—10GBASE-T and 10G SFP+.

If you choose 10GBASE-T, then upgrading the existing 1G network to 10G can be simple. If 10G switch is designed with RJ45 ports, you can use the same RJ45 network cable to connect the 10G switch with your server, storage and some other switches. The only difference is to use Cat6a network cable instead of Cat5e and Cat6 cable, because Cat6a can support 10G data rate over 100 meters; or you can choose SFP+ 10GBASE-T module with 2.5W power consumption and a maximum distance of 30 meters.

10G cabling

For 10G network switch that supports 10G SFP+, you can use it with devices that come with 10G SFP+ ports, too. For server or storage devices with 10G SFP+ port, the most cost efficient way to connect them with 10G network switch is to use 10G DAC cable (direct attach cable). It is basically copper cable with SFP+ connector on both sides. But this cabling way is only suitable for short connectivity. For data link over 100 meters, a pair of SFP+ modules and the matching fiber optic cable are needed. Depending on the length required in home network, you can use 10G optics such as 10GBASE SR SFP module and multimode fiber to reach 300 meters.


For home network set up, 10G is a trend. But before you migrate your network to 10G, you still have to think about what you want or what you need. After that, the choice for components and cabling procedure can be easy. FS.COM provides comprehensive 10G solutions: all the components mentioned to build a 10G home network are available at FS.COM, including 10G switches, network cables, 10G SFP+ transceivers, fiber patch cables and DAC cables. For more details, please visit

How Much Do You Know About PoE?

People’s increasing demand for more data traffic and higher data speed promotes the evolution of communication technology. The size of data center becomes larger and cabling system becomes more complicated. Recently, home network deployment springs up and a new network technology becomes a hot spot topic—PoE (Power over Ethernet). How much do you know about it? Do you use PoE devices? This article will focus on things related to PoE.


PoE technology allows network switches to transmit both power and data through an Ethernet cable at the same time. Take digital security camera for example. A digital security camera normally requires two connections to be made when it is installed: a network connection and a power connection. The former one makes the camera communicate with video recording and display equipment, while the latter one delivers the electrical power for the camera. However, if the camera is POE-enabled, only the network connection needs to be made, as it will receive its electrical power from this cable as well. Some equipment in home network usually use PoE, such as VoIP phone, IP camera and wireless access point.

POE applications


If you use PoE devices, you must have noticed that there are PoE+ devices on the market. What is the difference between them? PoE devices utilize the original PoE standard, IEEE 802.3af, which provides up to 15.4W of DC power to each device. While PoE+, also known as PoE class 4, is the latest standard, IEEE 802.3at, which provides up to 30W of power to each device. That’s to say PoE+ can provide almost twice as much power as PoE over a single Ethernet cable. High-powered IP devices such as PTZ cameras use PoE+. In addition, compatible NVRs use integrated PoE+ ports to provide power and PTZ commands to the camera, as well as video connection to the NVR.

PoE Switch

A PoE switch is a network switch that has Power over Ethernet injection built-in. It is straightforward to add PoE to your network. Simply connect other network devices to the PoE switch as normal, and the switch will detect whether they are POE-compatible and enable power automatically. PoE switches are available to suit all applications, from low-cost unmanaged edge switches with a few ports, up to complex multi-port rack-mounted units with sophisticated management.

PoE Switch

Advantages of PoE

PoE technology brings several advantages to home network deployment:

Time and Cost Savings: A single Ethernet cable can support both data and power transmission. Besides, running Ethernet cable does not require a qualified electrician, it can be done by yourself.

Flexibility: Without being tethered to fixed power outlet, there are more placement options for devices such as IP cameras and wireless access points, and they can be repositioned easily if required.

Safety: PoE delivery is intelligent, and designed to protect network equipment from overload, underpowering, or incorrect installation.

Reliability: PoE power comes from a central and universally compatible source, rather than a collection of distributed wall adapters. It can be backed-up by an uninterruptible power supply, or controlled to easily disable or reset devices.

Scalability: Having power available on the network means that installation and distribution of network connections is simple and effective.


PoE technology realizes the power and data transmission over the same Ethernet cable at the same time, which makes home network deployment more convenient. FS.COM provides high quality PoE switches and all of them come with a one-year limited warranty, including any quality problems during the free maintenance. For more details, you can visit our site.

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How Far Can 25G Ethernet Go?

Seeing from the evolution of data transmission speed and size of data centers, it is not difficult to find that the pressure on the data centers to manage data quality and transmission speed continues to grow, which leads to the need for faster data transmission over the network. Ethernet industry has laid a path to higher networking speeds like 100GbE, and 25G Ethernet has been developed to provide a simpler path to future Ethernet speeds of 50 Gbps, 100 Gbps and beyond. The release of the 25GbE specification provides cost-effective solution for server-to-switch connectivity. However, network will not stop the pace of development. How far can 25G Ethernet go? This article is going to focus on the question.

Overview of 25G Ethernet

25G Ethernet is a standard for Ethernet connectivity in a datacenter environment, developed by IEEE 802.3 task force P802.3by. The IEEE 802.3by standard uses technology defined for 100 Gigabit Ethernet implemented as four 25 Gbps lanes (IEEE 802.3bj). In 2016, 25G Ethernet equipment was available on the market, such as 25G SFP28 transceiver and DAC cable. In addition, 25G Ethernet supports for 100G using QSFP ports that can be converted to 4 lanes of 25 Gbps, like 100G QSFP28 transceiver. Here is a table of 25G Ethernet specification for you.

25G Ethernet specification

Advantages of 25G Ethernet

For 10G ToR to 10G Server connectivity, the simplest cabling solution is to use two 10G SFP+ transceivers and one fiber optic cable. When the network has to be upgraded to 25G Ethernet, the data center manager only needs to replace 10G SFP+ transceivers with 25G SFP28 transceivers. In the same way, we know that in 40G ToR to 10G Server connectivity, one 40G QSFP+ transceiver, four 10G SFP+ transceivers and one MTP to LC breakout cable are utilized. When this network deployment is upgraded to 100G ToR to 25G Server connectivity, the work can be quickly finished by replacing 40G QSFP+ transceiver with 100G QSFP28 transceiver, four 10G SFP+ transceivers with four 25G SFP28 transceivers. It can be easily found that there are some advantages when upgrading from 10G to 25G or 40G to 100G:

  • It can offer both CapEx and OpEx savings through backward compatibility, for investment protection and seamless migrations with consistent rack-design and reuse of the existing cabling infrastructure, avoiding costly and complex changes.
  • The technology utilized in 100G to 25G connectivity is similar to that in 40G to 10G connectivity, but the performance is increased by 2.5 times, thus reducing the power and cost per gigabit significantly.
  • 25G Ethernet provides higher port and system density than a comparable 40G solution.
  • Both power savings and higher density results in lower cooling requirements and operational expenditure for data center operators.

advantages of 25G Ethernet

How Far Can 25G Ethernet Go?

Considering the significant benefits and compelling economics of 25G Ethernet, it is no surprise that the move to 25GbE is accelerating—a recent five-year forecast by industry analysts at the Dell’Oro Group predicts 25G Ethernet will be the dominant Server port speed for new systems by 2018. You can learn about it from the following figure.

forecast for 25G Ethernet

However, never underestimate the need for industry consensus building. At present, 25GbE is mainly used for switch-to-server applications. If it can realize switch-to-switch application, 25G Ethernet may go further.


To be frank, 25G Ethernet indeed gains ground in some aspects compared to 10G and 40G Ethernet. If you plan to deploy 25GbE network, you can visit FS.COM which provides quality 25G SFP28 transceiver and various fiber optic cables.

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Choose A Right Fiber Switch for Your Network

As an important part of the whole network deployment, switch can be divided into many types according to different requirements, such as managed switch, 8 port PoE switch, lay2 switch, core switch and son on. Also, there are various band manufacturers on the market. How to choose a right fiber switch from a broad range of switches for your network deployment? This article will share some tips with you.

Case Analysis

Before we come to the useful tips, let’s have a look at a case.

Case description: I’m planning a large network deployment and I need a 10Gb fibre switch as the core switch to connect the distribution switches in a Metropolitan Area Network to the Datacenter. The scenario is a campus type setup. Ten separate buildings, between 50 and 600 meters away, connecting centrally to a Datacenter and NOC. At least 12 ports are need. The goal is to have high-speed connections to all buildings, preferably 10GbE, using fiber optic cable for the distance. So far I’m hoping for an lay3 core switch with SFP+ ports.

Case analysis: At first, you have to make a decision on singlemode or multimode fiber. If you choose singlemode fiber, you can use SFP-10G-LR-S transceiver for up to 10km. If you plan to to use multimode fiber, you are limited to 400m (on OM4) when using SFP-10G-SR-S transceiver. As for switch, any modern Cisco switch with SFP+ slots will support those transceivers, such as Catalyst 2960X, 3560X, 3650, 3850 etc. For the main site where you are bringing in connection from 10 buildings, you will need a switch with more than a couple of SFP+ ports. You can choose from Catalyst 3850 (WS-C3850-12XS for example or -24XS or -48XS versions for more ports), Catalyst 4500X (WS-C4500X-16SFP+, also available in 32 port version and either model can add an 8 port expansion module).

Catalyst 3850 10G SFP+ Switches

Figure 1. Catalyst 3850 10G SFP+ Switches

Catalyst 4500X 10G SFP+ Switches

Figure 2. Catalyst 4500X 10G SFP+ Switches

In addition, the 3850 switches can be stacked (except the 48 port all-SFP model), making adding in redundancy quite simple. The 4500X requires configuration of a Virtual Switching System (VSS) pair across two switches for redundancy. Either way ends up presenting a single control plane for configuration. (i.e., one configuration to manage). If you’re not well-versed enough in Cisco to be familiar with the basic switching offerings, I would not advise the Nexus switches. NX-OS is a bit different than IOS operating system and the features of the Nexus switches are aligned more with data center use cases than enterprise core. That said, they are perfectly capable for most uses—they just require a bit different configuration.

Tips for Choosing A Right Fiber Switch

From the above case, we can summarize some tips:

First, you have to make sure what type of fiber optic cable you want to use. For long distance, singlemode fiber is recommended; for short distance, multimode fiber can do well.

Second, according to your choice of fiber optic cable, you have to make a decision on data rate fiber optic transceiver. You have to know that which level you want your network to perform at? 10G, 40G or 100G? As for transceiver, usually, SR transceiver is used for short link and LR transceiver is applied for long distance transmission.

Third, you must figure out how many ports you need. If you want 12 port 10G SFP+, then you can buy Catalyst 3850 WS-C3850-12XS. If you want both SFP and 10G SFP+ ports, then you can try MikroTik CRS226-24G-2S+IN.

Fourth, you have to know that the operating system in switch varies from each other, for example, Cisco Nexus Series switches use NX-OS operating system.


This article shows a case which can overall illustrate the steps when choosing a right switch. What’s more, compatible issues of transceiver is also a critical question that you have to notice. FS.COM can provide quality transceiver for your network deployment. Like Cisco 2960x switch and Cisco Catalyst 3850 switch mentioned above, we have Cisco 2960 x SFP compatibility transceiver and Cisco 3850 SFP compatibility transceiver. For more details, you can visit our site.

10Gb Switches Under $550

Though many enterprise networks and big data centers have been upgraded to 40G or 100G Ethernet network, 10G Ethernet network still has its place in small homelab deployment. As an important component, 10Gb switch has been a hot topic among many engineers. If you are familiar with fiber optic networking, you must know the following brands: MikroTik, Dell, Ubiquiti and so on. They all provide 10G switches. And this article want to share some 10Gb switches under $550 with you.

MikroTik CRS226-24G-2S+IN

It belongs to MikroTik Cloud Router Switch series and it is powered by RouterOS. It is designed with 24 1GbE ports and 2 10G SFP+ ports. The price of MikroTik CRS226-24G-2S+IN on ebay is about $260. The datasheet of MikroTik CRS226-24G-2S+IN is shown as below:

the datasheet of MikroTik CRS226-24G-2S+IN
MikroTik CRS226-24G-2S+RM

The CRS226-24G-2S+RM is available in a 1U rackmount case. It is a fully functional Layer 3 switch powered by RouterOS. It has 24 Gigabit ports and 2 SFP+ cages for 10G connectivity (first SFP port supports 1.25G/10G modules, second port only 10G modules). The price of MikroTik CRS226-24G-2S+RM on ebay is about $280. The datasheet of MikroTik CRS226-24G-2S+RM is shown as below:

the data sheet of MikroTik CRS226-24G-2S+RM
MikroTik CRS210-8G-2S+IN

MikroTik CRS210-8G-2S+IN is a “small size low cost” switch. It comes with 8 Gigabit Ethernet ports and 2 SFP+ cages for 10G connectivity (first port supports 1.25G/10G modules, second port only 10G modules). The price of MikroTik CRS210-8G-2S+IN on ebay is about $187. The datasheet of MikroTik CRS210-8G-2S+IN is shown as below:

the datasheet of MikroTik CRS210-8G-2S+IN
Dell N2024

Dell Networking N2000 is a series of energy-efficient and cost-effective 1GbE and 10GbE switches designed for modernizing and scaling network infrastructure. N2000 switches utilize a comprehensive enterprise-class Layer 2+ feature set, deliver consistent, simplified management and offer high-availability device and network design. Dell N2024 is designed with 24 1GbE ports and 2 10G SFP+ ports. The price of it on ebay is about $400. The datasheet of Dell N2024 is shown as below:

the datasheet of Dell N2024
Ubiquiti ES-48-Lite EdgeSwitch

The Ubiquiti EdgeSwitch Lite simultaneously processes traffic on all ports at line rate without any packet loss. It can provide total non-blocking throughput up to 70 Gbps for the 48-port model. Ubiquiti ES-48-Lite EdgeSwitch has 48 Gigabit RJ-45 ports, 2 SFP ports and 2 10G SFP+ ports. The price of it on Amazon is about $420. The datasheet of Ubiquiti ES-48-Lite EdgeSwitch is shown as below:

the datasheet of Ubiquiti ES-48-Lite EdgeSwitch
TP-Link T1700G-28TQ

TP-Link T1700G-28TQ is designed to build a network that is highly accessible, scalable, and robust. It supports L2 and L2+ features. The switch is equipped with 24 10/100/100Mbps RJ-45 ports and 4 dedicated 10G SFP+ slots. The price of TP-Link T1700G-28TQ is about $400. The datasheet of TP-Link T1700G-28TQ is shown as below:

the datasheet of TP-Link T1700G-28TQ
D-Link DGS-1510-28X

D-Link DGS-1510-28X is a 1U rackmount switch that can be either mounted using ears or used in desktop mode. The front of the switch has the majority of the unit’s functionality present. It has 24 1GbE ports and 4 10G SFP+ ports. The price of D-Link DGS-1510-28X is about $520 on Amazon. The datasheet of it is shown as below:

the datasheet of D-Link DGS-1510-28X
D-Link DGS-1510-20

D-Link DGS-1510-20 has 16 1G ports, 2 SFP ports and 2 10G SFP+ ports. It can provide a reliable, scalable, and modular interconnection between core switch and edge switch with rich capabilities and simplified flexibility. The price of D-Link DGS-1510-20 is about $319 on Amazon. The datasheet of D-Link DGS-1510-20is shown as below:

the datasheet of D-Link DGS-1510-20

10Gb switch is still popular with small data center managers. I hope this article can help you choose a cost-effective 10Gb switch. FS.COM can provide quality components for your fiber optic cabling, such as SFP transceiver, fiber optic cable, cable management accessory and so on. For more details, please visit our site.