Archive | November 2016

The Truth About OS1 and OS2 Optical Fiber

Several years ago, OS1 fiber optic cable was the only one standard for single-mode fiber with the maximum link length for campus cabling around 10km, but 10km can no longer satisfy people’s increasing needs nowadays. Therefore, OS2 fiber that can support much longer distance than 10km has been widely utilized in telecommunication industry. But there has been some debate and confusion as to the differences between OS1 and OS2 fiber types and what the terminology actually means. Thus, the following article is provided to assist the users in understanding the differences between OS1 and OS2 fiber types. The following image shows the LC to LC fiber patch cable single mode plugging in a switch.


OS1 and OS2 Single-mode Fibers

Firstly, OS in the term OS1 and OS2 specifications refers to the Optical Single-mode fiber. Single-mode OS1 is indoor tight buffered fiber. An OS1 cable could be a micro-core LSZH indoor cable that consists of 250 micron fibers, with the fibers being tightly enclosed in a cable with aramid strengthening yarn and a LSZH jacket. The attenuation of a OS1 fiber is higher than an OS2 fiber. From the above table, the maximum attenuation allowed per km of installed cable is 1.0 dB for OS1 for 1310nm and 1550nm, while the maximum attenuation allowed per km of installed cable is 0.4 dB for OS2 for 1310nm and 1550nm.


Single-mode OS2 is an outdoor loose tube optical fiber cable, which is suitable for outdoor applications where the cabling process applies no stress to the optical fibers. For instance, a 250 micron coated multi-fiber, which is loose inside an enclosure or tube and/or is free to move, is classified as OS2.

OS1 or OS2 performance cables are constructed from B1.3 optical fibers (or ITU specification G.652D). Furthermore, OS1 and OS2 cable types can also include cables manufactured from B6_A fiber, which is commonly known as bend insensitive single-mode optical fiber, or ITU specification G657A2 (compatible with B1.3 optical fiber). OS1 or OS2 single mode fiber performance, does not relate to ITU specification G.655 (Non-dispersion shifted single mode optical fibers.

Why Should We Use OS2 Over OS1 Fiber?

Single-mode fiber was mainly used for long-hual applications but not marked as a cost-effective investment for future application in building. One reason is that the single-mode related products like cables and optical transceivers are offered with high price. The other is that with the price decrease of the VCSEL or laser power source, the performance gap (namely link length) between multimode or single-mode fiber is smaller everyday.

Considering this, why not use the best single-mode fiber (OS2) to create better performance and ready for high speed data networks? Besides the difference in link distance, OS1 and OS2 fibers have different attenuation—OS2 has two times less losses than OS1 fibers.  And in CWDM or DWDM network, OS1 has poor result in the wavelength range called E-band or water peak band, which makes it not suitable for the WDM-based network.


Figure 3: CWDM wavelength allocation and fiber loss. The solid line represents OS2 fibers. The dotted line represents the water peak.

Another good news is that if you use OS2 fiber, it will be more suitable for you to support the IEEE 802.3 multiplexed series (40G BASE-LR4 and 100G BASE-ER4). You even don’t need to change your existing OS1 fibers, as the OS2 can be mixed with OS1 in the same link. What’s more, active or passive component for OS1 like connectors, adapters also works with OS2.


To sum up, OS1 optical fiber is appropriate for indoor and universal tight buffered cable constructions, which are mainly deployed in internal building/campus networks, as well as internal cabling within telecommunication exchanges and data centers. While OS2 optical fiber is appropriate for outdoor and universal loose tube solutions, which would include external plant and most back-haul networks. Therefore, when deciding which single-mode optical fiber type to specify, consider the application as well as how and where the cable will be installed. For further information on optical fiber products, please contact FS.COM. Our fiber optic cable price is the cheapest with great feedback.

FS.COM SFPs for UniFi and Ubiquiti EdgeSwitch

There are a number of different switch options from Ubiquiti to power your devices. Ubiquiti EdgeSwitch and UniFi switch are the two commonly used type. Some users say that they are pretty much identical. But some said the differences appear very minor, I can definitely see that I would use each of the different models in distinctively different places to achieve the least headaches. Thus, today’s article have put together a comparison detailing the differences between each model to help you form the basic understanding of them.

UniFi Switch vs. Ubiquiti EdgeSwitch

According to the Ubiquiti, the Ubiquiti EdgeSwitch delivers forwarding capacity that simultaneously processes traffic on all ports at line rate without any packet loss. Ubiquiti EdgeSwitch targets the Broadband / ISP / Carrier market, which offers an extensive suite of advanced layer-2 switching features and protocols, and also provides layer-3 routing capability.

While The Ubiquiti UniFi Switch is available with either 24 or 48 RJ45 Gigabit ports. The UniFi Switch delivers robust performance, PoE+ support, and intelligent switching for growing networks. The UniFi switch targets the Enterprise / SMB market, which is designed for a wider IT audience, and therefore, tend to be simpler, and easier to use.

In short, both of them have four models and can support 1G SFP connectivity. The following part will go on to talk about these two switches and the compliant SFPs.

Introduction to Ubiquiti UniFi Switches

The UniFi Switch range has 4 models, offering either 24 or 48 ports at either 250 or 750 watts, which offers the forwarding capacity to simultaneously process traffic on all ports at line rate without any packet loss. The table below lists the comparison between the UniFi switches. For its total, non-blocking throughput, the 24port model supports up to 26 Gbps, while the 48-port model supports up to 70 Gbps. You can just pick the one that meet your current needs.


Cmpatible SFPs From FS.COM

From the above table, we know that each model includes two SFP ports for uplinks of up to 1 Gbps. The 48-port model adds two SFP+ ports for high-capacity uplinks of up to 10 Gbps, so you can directly connect to a high-performance storage server or deploy a long-distance uplink to another switch. For instance, the final model in the UniFi Switch series is the Ubiquiti UniFi US-48-750W. The US-48-750W is a 750W switch supporting 48 Gigabit RJ45 ports, 2 SFP ports and 2 SFP+ ports. For SFP ports, we can use SFP modules and fiber cable.

Available Ubiquiti EdgeSwitch

The Ubiquiti EdgeSwitch is a fully managed, PoE+ Gigabit switch, delivering robust performance and intelligent switching for growing networks. The EdgeSwitch offers an extensive suite of advanced Layer-2 switching features and protocols, and also provides Layer-3 routing capability. Just like the UniFi switch, the EdgeSwitch provides total, non-blocking throughput. Among 8-Port model up to 10 Gbps, 16-Port model up to 18 Gbps, 24-Port model up to 26 Gbps and 48-Port model up to 70 Gbps. The following table lists the comparison between EdgeSwitch modules.


Compatible SFPs With EdgeSwitch

The ubnt edgeswitch provides fiber connectivity options for your growing networks. The 8, 16, and 24-port models include two SFP ports, providing up to 1 Gbps uplinks. For high-capacity uplinks, the 48-port models include two SFP and two SFP+ ports, providing uplinks of up to 10 Gbps. Let’s take the ES-24-500W as an example, it is a powerful enterprise switch that offers an extensive suite of advanced Layer-2 switching features and protocols, and also provides Layer-3 routing capability. It also has 24 Gigabit RJ45 ports and 2 Gigabit SFP ports for 1G applications.

If you have purchased the Ubiquiti EdgeSwitch and want to buy some compatible modules and fiber optic cables. Then an article entitled “Which SFPs are compatible with the EdgeSwitch?” in Ubiquiti Help Center may help you out. Or you can directly come to FS.COM, we offer the following SFP transceivers that are tested to be fully compatible with EdgeSwitch switch. We also have a full range of fiber optics for sale.



The EdgeSwitches only support static routing, there are no routing protocols implemented. While UniFi Switches don’t support routing at all. Always ask your manufacturers first before buying the switches. FS.COM offers a series of Ubiquiti compatible SFP transceivers that can be used with EdgeSwitch and UniFi switch. In Ubiquiti Networks Community SFP modules compatibility section, some people tested Fiberstore SFP modules in their EdgeSwitch. The SFP1G-SX-85, SFP1G-SX-31 and SFP-10GSR-85 SFPs are working.

How to Set Up a LAN Network

Local area network (LAN) is the smaller network, usually within an office base or inside one building, which is used to connect computing resources including the computers, printers, servers, IP phones, or gateways. Connections within the LAN network are physical with cables, and all the office resources are shared and distributed between the network workstations. The most common type of LAN is the Ethernet—a family of frame-based computer networking technologies. But do you know how to set up a LAN system? What do you need while setting up the LAN network?

It is not a simple project to set up a LAN network (seen in the below image), especially for a beginners in telecom field. Thus it is advisable to make a comprehensive plan before making the next move. Network components like cable router, Ethernet cables, Ethernet switch and Network interfaces are the basics of a LAN network. Computers are connected to a switch with Ethernet cables. Make sure cable lengths do not exceed 100 meters, or about 300 feet. Each device are supposed to have a unique IP address. Besides that, you must first identify which services you need to provide locally on the LAN. The next part will move on to give you some detailed instruction about setting up a LAN network.


Six Instructions to Set Up LAN Network

Step 1. Identify the local services that you want available on the network. Identify network-attached printers, network disk drives, any server that will share printers or disks. Identify how many devices will have to connect to the network. Each device, server or workstation will require a unique address.

Step 2. Do not run cables in air ducts unless they are fire rated. A wired LAN will always get better performance and be more secure than a wireless LAN. Wherever possible, run a cable to servers, printers, IP phones or work locations. Run a cable to any area where you are likely to work. Use standard Ethernet cables like the cat6a cable or building wiring as installed according to the TIA-568 standard. The accessories like fiber optic wall plates, fiber patch cables, optical connectors are small but indispensable for a high performance LAN network just as seen in the below image.


Step 3. Use a switch or router with wireless capacity gives you more flexibility. The simple secure way to connect to the Internet is to use a cable router. Many types and models are available. If the model you choose does not have enough ports to connect all of your computers, then you will need to purchase a switch as well. Also a wireless router is needed in a modern LAN network.

Step 4. Configure the LAN ports of your cable router. Most cable routers will act as a Dynamic Host Configuration Server, or DHCP server. This means that the router will give addresses to workstations automatically. Be certain that the address pool has enough addresses for all of the workstations. Make certain that there are enough addresses outside of the range for any hosts that need static addresses. For example, a network address with a mask of has a total of 254 hosts. If the dynamic pool has 200 addresses available, that means the remaining 54 addresses are available to give printers or servers static addresses.

Step 5. Connect the wires for the network. Workstations and servers can be connected with standard Ethernet cables. Connect the switch to the cable router LAN ports by using the up-link or straight port on the switch. If the switch does not have an up-link port, connect any standard port of the switch to a LAN port on the cable router with an Ethernet crossover cable. Ethernet crossover cables can be purchased at any electronics store.

Step 6. Test the services and Internet connectivity. The actual performance of LAN network depends upon numerous factors including the cable specification, the quality of the installation and the connected devices. For this reason it is not sufficient to assume an installation will perform at the desired speed; its actual performance should be checked. It is advisable to test each of the workstations to ensure they can connect to the Internet and test any local servers and printers. Print test pages on the shared printers. Tests read and write permissions on shared file servers by copying files to the servers and copying files from the server to a workstation.



Although the above practices are a good starting point, there are no real one-size fitting all solutions as every small office is unique and has it own features. What matters when building a LAN network is how well you can assess your needs and pair them with the networking hardware that is available within your budget. FS.COM offers a series of optical devices including the Ethernet cables (Cat 5e cable, cat6a cable, cat 7 cable), fiber optic wall plate, optical connectors and cable testers. Our best buy ethernet cable is provided with high quality and great feedback. If you have any needs, you can have a look at our website.

How to Choose Between Coaxial Cable, Twisted Pair and Fiber Optic Cables?

As enterprises are striving for high reliability and performance as well as seamless data access and reporting, industrial networks are becoming more sophisticated. In terms of cabling solutions, it is essential to use the industrial Ethernet cable to achieve reliable performance. However, with so many fiber optics for sale, to select a right cable for broadband connection services is challenging. Coaxial cables and twisted pair or fiber optic cables are available for network connectivity. So which one is an ideal choice, coaxial cable or twisted pair cable? Is the fiber optic cable that fits your needs most? This article outlines the coaxial cable, twisted cable and fiber optic cables to help you select the right cable for your network.

Describing Coaxial Cable

Coaxial cable, or coax cable, is a single wire usually copper wrapped in a foam insulation. Because of its insulating property, coaxial cable can carry analogy signals with a wide range of frequencies. Thus it is widely used in feedlines connecting radio transmitters and receivers with their antennas, computer network connections, digital audio (S/PDIF), and distributing cable television signals. Over time, the industry settled on two characteristic coaxial cable impedances for the vast majority of applications: 50 Ohm and 75 Ohm.


The above figure shows the internal structure of the coaxial cables. In the middle of the coaxial cable is what is known as the center conductor. It can be made of either solid or stranded wire and is typically a mix of Aluminum and Copper. Surrounding the center conductor is something called the dielectric. The dielectric acts as a buffer of sorts to keep the center conductor isolated and straight. It usually is comprised of some blend of plastic and/or foam. Finally, on the outside of the dielectric is the coaxial cable’s shield, which is usually a combination of Copper and Aluminum foil and/or wire braid. The shield is then coated by something like PVC to insulate it from the environment.

Twisted Pair Cable Overview

Twisted pair cable is a type of copper wiring in which two conductors of a single circuit are twisted together. The twisting feature can avoid noise from outside sources and crosstalk on multi-pair cables, so this cable is best suited for carrying signals. Generally it comes in two versions: Shielded Twisted Pair (STP) and Unshielded Twisted Pair (UTP). STP is commonly used in Token Ring networks and UTP in Ethernet networks. Besides STP and UTP cables, twisted pair cables can be alao found in Categories cable. For instance, Cat 6 twisted pair cables are used for 1000BASE-T and 10GBASE-T networks. The image below displays the STP and UTP cables.


Finally Comes to Fiber Optic Cable

A fiber optic cable is a cable containing one or more optical fibers. Fiber optic cables often contain several silica cores, and each fiber can accommodate many wavelengths (or channels), allowing fiber to meet ever-increasing data capacity requirements. When terminated with LC/SC/ST/FC/MTRJ/MU/SMA connectors on both ends, fiber optic cables can achieve fiber link connection between equipment during fiber cabling. Nowadays, two types of fiber optic cables are widely adopted in the field of data transfer—single mode fiber optic cables and multimode fiber optic cables. Take LC to ST fiber cable for example, the LC to ST 10G OM4 multimode fiber cable (seen in the below image) is utilized for 10G short-reach applications, while the LC to ST single-mode fiber cable can be used for long-reach application.


Comparison Between These Cables

When considering which kind of fiber cable is appropriate for network services, one thing you should keep in mind that each type of cable has its unique advantages and disadvantages concerning about these factors—cost, speed, security, reliability, bandwidth, data carrying-capacity, and so on.

Coaxial Cable can be installed easily, relatively resistant to interference. However, it is bulky and just ideal for short length because of its high attenuation. It would be expensive over long-distance data transmission. While Twisted Pair Cable is most flexible and cheapest among three kinds of cables, easy to install and operate. But it also encounters attenuation problem and offers relatively low bandwidth. In addition, it is susceptible to interference and noises.

As for fiber optic cables, it is treated as the most popular mediums for both new cabling installations and upgrades, including backbone, horizontal, and even desktop applications. Compared with the other two cables, fiber optic cable is small in size and light in weight, and the conductor is glass which means that no electricity can flow through. In addition, fiber cable is immune to electromagnetic interference. The biggest advantage of fiber optic cable is that it can transmit a big amount of data with low loss at high speeds over long distance. Nevertheless, it needs complicated installing skills, difficult to work with and expensive in the short run.


With all the features and disadvantages of the cables listed above, it is time for for you to make your won choice. Note that the cost of the cable is compared to the high costs of network failure, which can be thousands of dollars per minute. Therefore it is make sense to choose and install the right cable for your LAN network. FS.COM provides a full range of fiber optics including the cables, optical transceivers, patch panels, and fiber enclosures, etc. Other cables such as Cat 5e, Cat 6, Cat 6A are also available for your copper networks. Welcome to visit FS.COM for more detailed information.

Cisco SFP Transceivers Overview

Cisco Small Form-Factor Pluggable (SFP) transceiver can be defined as a device that comprises of both a transmitter and a receiver of analog or digital signals. It is a compact, hot swappable, input/output device based on the available fiber cable type (copper cable or multimode/single-mode optical fiber). In addition, SFP transceivers can be leveraged both at 100Base and 1000Base rates in the following standards:


SFP transceivers are mainly used to link equipment in telecommunication and data communications like switches and routers. They support applications like 2G/4G Fiber Channel, SONET/SDH Network, Gigabit Ethernet, High-speed computer links, and with CWDM and DWDM interfaces. Today’s article will generally introduce the Cisco SFP transceivers including the Cisco 100M SFP, Cisco 1000BASE SFP, CWDM/DWDM SFP, SONET/SDH SFP as well as Cisco BiDi SFP to you.

Cisco 100Mbqs SFP

Cisco offers two different types of 100BASE SFP—100BASE SFP for Fast Ethernet (FE) SFP Port and 1000BASE SFP for Gigabit Ethernet (GE) port. Besides the above standards, the Cisco 100BASE SFP portfolio includes 100BASE-FX, 100BASE-LX, and 100BASE-BX SFPs.

Cisco 100BASE-FX SFP operates on MMF for link spans of up to 2km. 100BASE-LX SFP operates on SMF up to 10km. 100BASE-BX SFP operates on SMF for a link length of up to 10km. A pair of a 100BASE-BX-D and a 100BASE-BX-U SFP is needed for the single strand deployment. The following table displays the compatible Cisco 100M and 1G SFPs from FS.COM.


Cisco 1000BASE SFP

Cisco 1G SFP transceivers offer a convenient and cost-effective solution for the adoption of Gigabit Ethernet and Fibre Channel in data center, campus, metropolitan area access and ring networks, and storage area networks. They are available in several Gigabit standards—1000BASE-T, 1000BASE-SX, 1000BASE-LH, 1000BASE-EX, etc. Take Cisco GLC-LH-SM as an example, it operates over standard single-mode fiber spanning distances of up to 10 km and up to 550 m over any multimode fiber (OM3/OM4). If 1000BASE-LX/LH SFP transceiver transmits in the 1300nm wavelength over OM1/OM2 fiber, it requires mode conditioning patch cables.

Cisco CWDM/DWDM SFP Modules

Cisco Coarse Wave Division Multiplexing (CWDM) solution allows scalable and easy-to-deploy Gigabit Ethernet and Fibre Channel services. Similar with traditional SFP module, the Cisco CWDM SFP is a hot-swappable input/output device that plugs into a SFP port or slot of a switch or router. CWDM SFP transceiver modules make use of the SFP interface for connecting the equipment and use dual LC/PC fiber connector interface for connecting the optical network with a link distance of up to 80km. It usually comes in 8 wavelengths covering from 1470 nm to 1610 nm. Color markings on the devices identify the wavelength to which the Gigabit Ethernet channel is mapped. The following picture lists the FS.COM compatible Cisco CWDM SFPs with their wavelengths and color codes.


DWDM (Dense Wavelength-Division Multiplexing) SFP transceivers, however, are used as part of a DWDM optical network to provide high-capacity bandwidth across an optical fiber network. Cisco DWDM SFP is a high performance, cost effective module for serial optical data communication applications up to 4.25Gb/s. There are 32 fixed-wavelength DWDM SFPs that support the International Telecommunications Union (ITU) 100-GHz wavelength grid.

Cisco SONET/SDH SFP Modules

This Cisco SONET/SDH SFP is compatible with the SONET/SDH standards, and support the digital diagnostic functions specified in the SFF-8742 Multi-Source Agreement (MSA). Cisco SONET/SDH SFP can be directly plugged into a variety of ports on Cisco router interfaces. These SFP optics support OC-3, OC-12, and OC-48 data rates for multimode, short-reach, intermediate-reach, and long-reach (up to 80 km) applications just as seen in the below chart.


Cisco BiDi SFPs

Bidirectional (BiDi) SFP transceivers can transmit and receive data to/from interconnected equipment through a single optical fiber. BiDi transceivers are fitted with wavelength division multiplexing (WDM) diplexers, which combine and separate data transmitted over a single fiber based on the wavelengths of the light. BiDi transceivers must be deployed in matched pairs, with their diplexers tuned to match the expected wavelength of the transmitter and receiver that they will be transmitting data from or to. These transceivers offer bi-directional data links over single-mode fiber up to 120 km.

Take 1000BASE-BX SFP BiDi transceiver as an example, 1000BASE-BX SFP modules are compliant with SFP Multi-Source Agreement (MSA) specification and SFF-8472, and conform to the IEEE 802.3ah 1000BASE-BX10 standard. 1000BASE-BX SFP modules include 1000BASE-BX-U SFP module and 1000BASE-BX-D SFP module. The 1000BASE-BX-D SFP operates at wavelengths of 1490nm TX/1310nm RX, and the 1000BASE-BX-U SFP operates at wavelengths of 1310nm TX/1490nm RX. These transceivers use standard simplex LC connectors for fiber cable connection and provide a long transmission distance of up to 10 km.


It is necessary to select the suitable SFP transceivers for your network. This article has concluded several types of Cisco SFP transceivers, which might be a great help for those who are looking for Cisco SFPs. FS.COM, a leading and professional fiber optic SFP transceiver module provider, has a large inventory of 1000BASE SFP, 100BASE SFP, CWDM/DWDM SFP, BiDi SFP, etc. If you have any needs of our transceivers, please send your request to us.

Guide to QSFP28 Transceivers for 100G Data Center Connectivity

Using standard transceivers and cables is the most straightforward way to upgrade to 100G traffic. However, there are several types of 100G optics (transceivers and cables) available on the market like the CFP, CFP2, CFP4 and QSFP28 fiber optic assemblies. QSFP28 transceivers offer the cost-optimized solutions for connecting 100G switches together in a rack or data center, which become very popular in the 100G connectivity. Today, we are going to introduce this smallest 100G form factor transceiver—QSFP28 to you.

QSFP28 Optical Transceivers

It is notable that QSFP28 transceiver not only have the same physical size as the QSFP+ used for 40G traffic, but the lowest power consumption among those that are capable of handling 100G traffic. The QSFP28 interconnect offers four channels of high-speed differential signals with data rates ranging from 25 Gbps up to potentially 40 Gbps, and will meet 100 Gbps Ethernet and 100 Gbps 4X InfiniBand Enhanced Data Rate (EDR) requirements. There are basically two types of QSFP28 transceivers seen in the below image.


QSFP28-SR4 transceivers is specially designed to support connections of up to 100 meters over multimode fiber. This approach is similar to using AOC cables, but here it is possible to use structured cabling. They use more expensive non-standard MPO (multi push-on/pull-off cable) connectors which cancel out some of the cost savings of the transceiver. QSFP28-LR4 versions support connections up to 10km over single-mode fiber. They use standard LC connectors and the existing structured LC cabling.

For distances longer than 10km, there have also been some recent breakthroughs in transceivers with DWDM capabilities, most significantly the PAM4. To be effective, however, the DWDM QSFP28 PAM4 requires amplification for even very short distances, and for any distance over 5 or 6km, needs dispersion compensation. With this, it can handle data traffic up to 80km.

QSFP28 Cable Assemblies

Compared to the QSFP28 transceivers, QSFP28 cable (DAC or AOC cables) is the more convenient, low-cost method of connecting 100G equipment. And most importantly, using a single cable assembly removes many of the problems associated with dirty connectors. DAC is suitable for applications within 15m and AOC up to 70m. AOC cable assemblies provide similar performance to discrete transceivers and fiber cables. The following image shows a QSFP28 AOC (left) and QSFP28 DAC cables (right).


QSFP28 Application

No matter you choose to use the QSFP28 transceivers or cables, they are indeed the ideal solution for switch vendors who need to handle data that stays within the rack and the data center. QSFP28 offers the perfect fit for these scenarios. However, for the 100G longer distance, the CFP and CFP2 offer DWDM Coherent technology and enable multi-channel long distance connectivity of more than 1000km. One thing we can’t miss is that the CFP is too big to be used in an Ethernet switch in volume.

Even though a vendor chooses the smaller CFP2 or CFP4, the size and power are often unrealistically high. One solution is to offer CFP DWDM support for those few links where it’s required, but even there, the increase in power consumption and the decrease in available ports have an impact on the overall cost-effectiveness of the switch.


The QSFP28 fiber optic solution that offers the best of both worlds allows the user to get the full benefits of QSFP28 transceivers and cables in the datacom equipment, but also gets the advantages of high-speed traffic transportation between sites. FS.COM offers a variety of 100G modules, DACs and AOCs, as well as the cable assemblies and management hardware which can satisfy short or long reach applications. For more detailed information, please contact us directly.