What Distance Can 100G QSFP28 Transceiver Support?

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

100G QSFP28–Supported Distance Below 1km

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

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

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

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

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

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

qsfp28-lr4

100G QSFP28–Supported Distance Over 10km

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

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

Conclusion

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

 

Does Multimode SFP Work Over Single-mode Fiber Cable?

When you prepare to connect some SFPs with fiber patch cords, you may find SFPs are multimode modules while your fiber cables are single-mode. Try to connect those optics to fiber cable, but no green light and the link fails. So multimode SFPs can’t work over single-mode fiber cables. To avoid the wasting of time and money, you should better know well about single-mode and multimode SFPs and fiber patch cords.

Single-mode and Multimode SFP

SFP, small form factor pluggable transceiver, can support the data rate up to 1Gbps. SFPs can be divided into single-mode and multimode modules.

For single-mode SFPs, there are “LX” for 1310 nm and “EX” “EZX” for 1550 nm. Single-mode SFPs are designed to transmit signals over long distances. For example, Cisco GLC-LH-SM-15 compatible 1000BASE-LX/LH SFP 1310nm 15km DOM transceiver, main product information is shown as follows:

  • Wavelength: 1310 nm
  • Interface: LC duplex
  • Max Cable Distance: 15 km
  • Max Data Rate: 1000Mbps
  • Cable Type: SMF

Comparatively, multimode SFPs are identified with “SX”. This kind of optics is specially for short distance data transmission. For instance, Cisco GLC-SX-MM compatible 1000BASE-SX SFP 850nm 550m transceiver, this is a typical multimode SFP.

  • Wavelength: 850 nm
  • Interface: LC duplex
  • Max Cable Distance: 550m over OM2 MMF
  • Max Data Rate: 1000Mbps
  • Cable Type: MMF

SFP-LX and SFP-SX

Single-mode Fiber Cable and Multimode Fiber Cable

Fiber patch cables are used to connect transceivers on your switch/device. You have to buy the right fiber cable type for your optics. Fiber cable has two different categories: single-mode and multimode.

Generally, single-mode fiber cable can support further distance because of lower attenuation, but the price is higher. While multimode fiber cable has a larger core, usually multimode fiber cable is constructed in 50/125 and 62.5/125. It allows multiple modes of light to propagate. When the light passes through the core, the light reflections increases and more data can be transmitted at given time. As the high dispersion during signal transmission, the link distance gets reduced. So multimode fiber cable is for short distance application. Multimode fiber cable is a little more complex than single-mode fiber cable since it includes four different types of OM1, OM2, OM3, OM4. OM1 and OM2 fiber patch cable can support the data rate up to 10Gbps. OM3 and OM4 are laser optimized so that they can be used in high density data center to support the data rate of 40Gbps and 100Gbps. The following table shows how long each kind of fiber cable can reach running at different data rate.

Fiber Mode Cable Type 1GbE 10GbE 40GbE 100GbE
Single-mode OS2 100km 40km 40km 40km
Multimode OM1 275m(SX) 33m(SR) / /
OM2 550m(SX) 82m(SR) / /
OM3 550m(SX) 300m(SR) 100m 100m
OM4 1000m(SX) 400m(SR) 150m 150m

Note: “SR” implies multimode 10Gpbs SFP+.

For more information about single-mode and multimode fiber cable, you can refer to my previous articles:
What Is Single Mode Fiber?
What Are OM1, OM2, OM3 and OM4?

Solutions for Multimode SFP

If you have Cisco Catalyst 3650 WS-C3650-48PS switches with 4x1G uplink ports, to build a 300m-network link, you are gonna purchase fiber patch cable and SFP modules. What kind of optical equipment should you choose?

As to the SFP module, you need Cisco GLC-SX-MM 1000BASE-SX SFP. Or you can spend less money on third-party SFPs with 100% compatibility. Next step, you need to find suitable fiber patch cable to match this type of SFP. Since 1000BASE-SX SFP is multimode, of course you need multimode fiber cable. Considering the distance of 300 meters, OM1 can only reach 275 meters. So OM2 is the best choice for it’s the cheapest and can reach 550 meters.

1000BASE-SX SFP connection

Conclusion

It’s obvious that multimode SFPs can’t work over single-mode fiber cables. When buying SFPs, watch the standards on the label carefully and find if it’s “SX” or “LX”, “EX”. If it shows “SX”, then find multimode fiber patch cable. It’s not very difficult to choose right cable for your SFP modules.

How to Select Fiber Patch Cable for 40G QSFP+ Modules?

As the speed changes from 1 to 10 Gbps and now increases from 10 to 40 Gbps and even 100 Gbps, data centers develop into more complex systems. So different optical technologies and cabling infrastructure are required. For 40G data rates, the special transceiver module is QSFP+ (Quad Small Form-Factor Pluggable Plus). To build 40G data centers, you need to select suitable fiber patch cable for 40G QSFP+ Modules. But how?

40G transmission network needs advanced switch, matched patch cords and transceiver modules. The quality of these connections can largely affect the reliability and stability of the whole 40G network. However, connectivity of 40G is much more complex than ever. Thus, selecting the proper fiber patch cables for 40G network is more difficult and becomes a big issue in 40G migration. As mentioned, QSFP+ transceivers are suggested for 40G, this article will provide as detailed as possible about fiber patch cable selection for 40G QSFP+ transceivers.

40G QSFP+ transceivers

Patch cable is very important to 40G network not only because the switch connections necessity, but also because of the transmission principle of the fiber optic signals and the high density trend of 40G transmission. Several important factors like cable, connector and switch port should be taken into account when selecting patch cords for 40G QSFP+ transceivers.

Single-mode or Multimode Fiber Patch Cable

Fiber Patch Cable able is essential for the network performance. Optical signals perform differently when information transforms through the cables with different wavelengths. When people buy fiber optical patch cords for 40G QSFP+ transceiver, they often ask if a 40GBASE universal QSFP+ transceiver working on wavelength of 850nm can be used with OM1 patch cords. The answer is yes, but not suggested. Why? As the optical signal transmission distance gets shorter, the data rate increases. The transmission distance and quality would be limited by using OM1 optical cable with 40G QSFP+ transceiver. OM1 cable is only suggested for 100 Mb/s and 1000Mb/s transmission. Two upgraded cables—OM3 and OM4 are suggested for 40G QSFP+ transceivers in short distance.

IEEE has announced standards for 40G transmission in both long distance and short distance, which are 40GBASE-LR4 and 40GBASE-SR4. (LR stands for long reach and SR stands for short-reach and). For long reach, single-mode fiber is suggested for 40G transmission with the distance up to 10 km. For short reach, multimode fiber—OM3 (up to 100 meters) and OM4 (up to 150 meters) is suggested for 40G transmission. OM3 and OM4, which are usually aqua-colored, are accepted economic solutions for 40G in short distance with lower insertion loss and higher bandwidth.

MTP or LC Fiber Patch Cable 

The connector type of the patch cords should depend on the interface of 40G QSFP+ transceiver. Now there are two interfaces commonly adopted by 40G QSFP+ transceiver and they are MTP and LC. Usually 40G QSFP+ transceiver with MPO interface is designed for short transmission distance and LC for long transmission distance. However, several 40G QSFP+ transceivers like 40GBASE-PLR4 and 40GBASE-PLRL4 have MPO interfaces to support long transmission distance.

mtp and lc connectors for qsfp+

High density is the most obvious characteristic of 40G transmission, which is largely reflected in the MTP connectors on patch cords used with 40G QSFP+ transceiver. As QSFP+ transceiver uses four 10G channels, MTP cable which uses 4 pairs of fibers with can provide a time-save and stable solution for 40G QSFP+ transceivers.

Besides, 40G QSFP+ transceiver with LC interface is also available. This type of QSFP transceiver uses four lanes with each carrying 10G in 1310nm window multiplexed to achieve 40G transmission. For this type, patch cable with duplex LC connector should be used.

Switch Port

The importance of network flexibility gradually reveals as the speed of Ethernet increases. Cabling options for 40G network are 40G QSFP+ to 40G QSFP+, 40G QSFP+ to SFP+. It’s very common that 40G ports is needed to be connected with 10G port. In this case, fan out patch cable with MTP connector on one end and four LC duplex connectors on the other end is suggested (as shown in picture below).

Factors like single-mode or multimode fiber jumpers, fiber patch cable connector and switch port are important in selecting the right patch cords for 40G QSFP+ transceivers. They are closely related to the transmission distance, network flexibility and reliability of the whole 40G network. But in practical cabling for 40G QSFP+ transceivers, there are more need to be considered. Planning and designing takes a lot of time and may not achieve results good enough. However, Fiberstore can solve your problems with professional one-stop service including the cost-effective and reliable network designing and 40G products.

Originally published at http://www.articlesfactory.com/articles/communication/how-to-select-fiber-patch-cable-for-40g-qsfp-modules.html

Tips for Fiber Cable Installation You Should Know

Fiber cable installation is not an easy task for most of us. It’s thought as the job of professional engineers since special training is needed during the complicated process. But it would be better if you know knowledge of fiber cable installation in case that you need to run fiber cable in your home or business. This article is going to offer you some tips for fiber cable installation.

fiber-cable-installation

Before Fiber Cable Installation

Before starting fiber cable installation, please make sure there is fiber optic service in your area. If it’s available, find the nearest distribution box. What you need to do is to run fiber cable from the box to your house.

A considerate plan is the first step of successful fiber cable installation. Carefully design the cabling route. It would be better if you mark where the cable goes, into the walls, or underground, or through conduit… Point out all the termination points and splice points. At the same time, write down any potential problems you may come across during the installation. A good plan is also beneficial to avoid fiber cable waste.

Once finish the plan, you’re going to buy fiber optic cable for your applications. Except fiber optic cable, you need tools for cable management & installation, fiber splicing and fiber testing. So make a shopping list for your fiber cable installation. Then select a reliable fiber cable supplier who can meet the requirements of both high quality and low cost.

During Fiber Cable Installation
What You Should Do

Leave spare cable length—Each fiber cable for installation should be a few inches longer than the plan says. Because you can’t make sure everything goes as you wish. So you should leave plenty of spare fiber cables when beginning cable installation work.

Avoid electrical interference—Though fiber cable is not as vulnerable to electrical noise as copper cables, some devices, such as the boxes for fluorescent lights, may cause interference. So keep your fiber cable three or more feet from those devices.

Avoid end face contamination—The tip of fiber optic connector can be easily contaminated or damaged. So leave protective caps on until you are ready to plug into the equipment. Don’t forget to inspecting the end face before plugging in. If there is any contaminate, clean it.

Fiber network testing—Test each section of your fiber optic network. That’s easy to discover the problem and troubleshoot it. Don’t do this work until you finish the entire cable installation. In that situation, it’s hard to find out the trouble if the network fails.

What You Should Not Do

Don’t bend fiber cables. Fiber optic cables perform the best when it is running straight. But during installation in reality, sometimes bending can’t be avoided. Cables from different vendors may have different standards of bend radius. Or you can buy bend insensitive fiber cable for better performance.

Don’t pull too hard on the cable. Properly pull the fiber cable to avoid bending or snagging through the conduit or underground. However, don’t pull it too hard especially when the fiber cable is too short. Otherwise, it would ruin the cable or fiber optic connector.

Don’t mix and match different core sizes. Fiber optic cables are typically color coded. From the outside cable jacket, you can get information about fiber core sizes. To know more about fiber cable jacket, you can visit my last blog What Can We Get From Fiber Cable Jacket?

Don’t pinch the fiber cable. Pinch the fiber cable can squeeze the fiber and affect link performance. When use zip-ties, pay attention to this point.

Conclusion

Once you finish fiber cable installation, you can enjoy fiber optic network. See, fiber cable installation is not as tough as you think. Follow these tips mentioned above when you run cables for your house, you can keep away from most bothering issues.

What Can We Get From Fiber Cable Jacket?

Fiber optic cable is applied as the most advanced communication medium by more and more users. Compared with copper cable, it can support more and better optical signal transmission of voice, data, video, etc. and offer many other advantages. When purchasing fiber optic cables, you must see the cable jacket at first. So what information does the outside jacket tell? What type of cable jacket should you select? Come with me to find the secrets of fiber cable jacket.

Fiber Cable Jacket Introduction

Fiber optic cable is constructed very complicated from the inside core, cladding, coating, strengthen fibers to the outside cable jacket. The core made of plastic or glass is the physical medium for optical signal transmission. As bare fiber can be easily broken, cable outer jacket is needed for fiber protection. The cable jacket is the first line of moisture, mechanical, flame and chemical defense for a cable. Without the jacket, fiber optic cables are very likely to be damaged during and after installation.

fiber-cable-jacket

Fiber Cable Jacket Characteristics

In most situations, robust cable jacket is better because the environment above or underground may be harsh. For better applications, you’d better take cable jacket seriously. Cable jacket is not as easy as you think. There are many characteristics you need to consider. Except the flexibility, it should withstand very low and high temperature. Whether the cable jacket has the good features of chemical and flame resistance. All these characteristics depend on cable jacket materials.

Fiber Cable Jacket Materials

Cable jacket is made of various types of materials. As mentioned above, the cable jacket should stand the test of different environmental conditions, including the harsh temperature, the sun & the rain, chemicals, abrasion, and so on. The following shows several common cable jacket materials for your reference.

PE (Polyethylene)—PE is the standard jacket material for outdoor fiber optic cables. It has excellent properties of moisture and weather resistance. It also has the good electrical properties over a wide temperature range. Besides, it’s abrasion resistant.

PVC (Polyvinyl Chloride )—PVC is flexible and fire-retardant. It can be used as the jacket materials for both indoor and outdoor cables. PVC is more expensive than PE.

LSZH (Low Smoke Zero Halogen)—LSZH jacket is free of halogenated materials which can be transformed into toxic and corrosive matte during combustion. LSZH materials are used to make a special cable called LSZH cable. LSZH cables produce little smoke and no toxic halogen compounds when these cables catch fire. Based on the benefits, LSZH cable is a good choice for inner installations.

Fiber Cable Jacket Color

Fiber cable jacket color depends on the fiber cable type. Fiber cable includes single-mode and multimode types. For single-mode fiber cable (Blog about single-mode fiber cable please read my blog What Are OM1, OM2, OM3 and OM4?), the jacket color is typically yellow. While for multimode cable ( more details on multimode fiber cable ), the jacket color can be orange (OM1&OM2 cable), aqua (OM3 cable) and purple (OM4 cable). For outside plant cables, the jacket color is black.

How to Choose Fiber Cables?

To choose a fiber optic cable depends on your own applications. I’ll talk about this from two sides of jacket color and jacket material. The cable jacket color is not just for good looking. Different color means different fiber mode. Which one suits you the most, the yellow or orange fiber cable? You should know well about the color codes before buying your fiber cables. What’s more, you should also consider the installation requirements and environmental or long-term requirements. Where will be your fiber cables installed, inside or outside the building? Will your cables be exposed to hash environment very long? This can help you decide which jacket material is the best.

Summary

As a popular data transmission medium, fiber cable plays an important role in communication field. To some degree, the success of fiber connectivity lies in a right fiber cable. How to buy suitable fiber optic cables? This article describes the method from cable jacket. When selecting fiber cable, many other factors still need to be considered. Hope you can get your own fiber cable.

Selection Guide on PoE Switch

Currently IP cameras are widely used for video surveillance due to the high requirements for security. Typically, the IP cameras are with PoE functions, then PoE switch is needed for the connection. But some users feel confused about the PoE switch and don’t know how to choose a suitable PoE switch. This article is going to introduce you some guides on PoE switch selection.

What Is PoE and PoE Switch?

PoE is short for power over Ethernet. With PoE technology, data and power can be transmitted over a single Cat5e cable. A PoE switch is a device that contains multiple Ethernet ports to provide power and network communications to IP cameras. PoE switch is an economical and reliable solution for small business networks to deploy wireless access points and IP surveillance cameras.

Fiberstore poe switch

Considerations for PoE Switch Selection
Numbers of Ports

The most important is to check whether the numbers of ports on PoE switch are enough to connect all your devices. Fiberstore offers PoE switches including 8 ports, 24 ports, and 48 ports. PoE ports are flexible to connect with Cat5e cable without additional settings. All of our PoE switches have 2 Gigabit uplink SFP ports or 4 SFP+ ports. Uplink ports allow long distance data transmission between switches. With these ports, you can easily expand your networks. (Check news about PoE switch from FS.COM: Build and Expand Your Network with FS.COM New Introduced PoE Switches) So if you need to link multiple switches, you need to select switches with enough Gigabit ports.

Power Supplies for Powered Device

PoE switch applies two standards: IEEE802.3af and 802.3at. Each one can offer power for IP cameras. Due to the different standards, the output power of PoE switch is also different. IEEE802.3af can provide 15.4watts DC power on each port. As some power dissipates in the cable, only 12.95watts power at most can be supplied to powered devices. This standard is enough to power VoIP phones, wireless access points and some cameras over standard Ethernet cabling. While, IEEE802.3at is updated PoE standard known as PoE+. It can provide up to 25.5watts power available for powered device which is nearly twice as many as that 802.3af supplies. The updated standard can support more devices with high-power functionality such as door controllers, cameras with zoom capacity, or wireless access points supporting 802.11n.

Total Power

PoE switch has a total power. As described before, under IEEE802.3af standard, each port on the PoE switch can get 15.4watts power. Thus, the total power of a 24-port switch must reach 370watts so that it can make sure each port get sufficient power. And make sure there is additional power beyond that required for PoE for its switching functions. As to the IEE802.3at standard, each port supports 30watts. Under this condition, the PoE switch with total power of 370watts can only provide power supply to 12 ports.

Cable Requirements

The DC power of IEEE 802.3af standard is 15.4watts. It can support 10BASE-T and 100BASE-T. Two of four twisted pairs of Cat3 cable or higher can support the power and data transmission. The PoE+ standard delivers power up to 30watts and supports 1000BASE-T. Cat5e or Cat6 cable is able to support the power transmission. Connecting PoE switch to the router or cameras with Cat5e or Cat6 cable, the maximum transmission length is up to 100 meters.

When buying Ethernet cables, find a reliable vendor who provides standard network cable meeting the strict requirement. PoE power supply must use oxygen-free copper material—standard network cable. Non-standard cable utilizes other materials such as copper clad steel, copper clad aluminum, copper coated iron, etc. These cables are not suitable for PoE power supply because of the big resistance.

Conclusion

PoE switch is a cost-effective solution to increase the reliability and security of networks by providing centralized backup power to all connected IP surveillance devices. Before purchasing PoE switches, try to know as more details about the switch specifications as possible and also your own needs. To get good quality PoE switches, please come to FS.COM.

How to Choose a Wireless Access Point?

Nowadays, wireless LAN (local area network) becomes an independent part in our daily life. As waiting for your dishes in a restaurant, you may take out your phone and connect the Wi-Fi. I guess most of you have a wireless LAN. But if you have no or intend to upgrade your network, you’d better read this article on how to choose a wireless access point (AP).

fs-wifi-ap

Wireless AP Standards: 802.11n and 802.11ac

There are two newest IEEE wirelesss network standards including 802.11n (debuting in 2009) and 802.11ac (in 2014). The earlier 802.11n standard can support up to 540 Mbps, while the optimized 802.11ac products can provide the speed up to 1.3Gbps. 802.11ac is faster and more scalable than 802.11n. Except the improved speed, 802.11ac access points also optimize in the areas of range and reliability. Considering these factors, many enterprises may use 802.11ac technology.

However, though 802.11ac is better than 802.11n, it doesn’t mean it suits for everyone. First, 802.11ac needs big room for super wide channels. Second, you need to buy devices matching 802.11ac technology. At last, those devices should be close (20 or 30 feet) to the access point.

Dual Band Wireless AP or Single Band Wireless AP

Before discussing about dual band and single band, we need to know 2.4 GHz and 5 GHz. 2.4 GHz is a lower frequency than 5 GHz. It can penetrate most obstructions better. The signal can reach further. Wireless access point is one of the devices which use 2.4 GHz. While 5 GHz has a higher frequency, signals can’t penetrate solid obstructions like walls as easily as 2.4 GHz. 5 GHz provides us with more usable channels.

dual-band-wireless-ap

In the past, some 802.11n wireless AP is single band and can only support 2.4 GHz. It fails to meet the demands for 5GHz devices. Thus, the trend urges the appearance of new dual-band access point. Dual-band means that the access point can transmit and receive in two separate bands. Dual-band access points can support 2.4 GHz speeds and leverage wide channels, high data rates for connecting 5GHz devices. When you buy access points, make sure the one you choose can support both 2.4 GHz and 5 GHz.

Spatial Streams of Wireless AP

The number of spatial streams is one of the influencing factors on wireless speed. 802.11n stopped at four spatial streams, but 802.11ac goes all the way to eight. 802.11n introduced MIMO (more multiple input, multiple output). MIMO means that we can get multiple radio chains and antennas to transmit and receive. The more radio chains, the faster the wireless network speed. With 802.11n, a device can transmit multiple spatial streams at once, but only directed to a single address. It means only one user can get data at a time. That’s called single-user MIMO (SU-MIMO). While with 802.11ac, multi users can get data at the same time. And that’s called multiuser MIMO (MU-MIMO). As you can see, the more spatial streams, the better.

Get Wireless APs From Fiberstore

We provide three types of wireless APs which can be applied to enterprises, schools, hotels, etc. Our wireless APs contain the good features of easy plug & play installation and intuitive management, which is beneficial for reducing the need for dedicated IT personnel resources. And the unique watchdog technology makes AP work more stable and ensure the wireless network operate properly. Repeater mode makes wireless coverage more flexible. Both 802.11n and 802.11ac APs (as shown in the table below) can be found in Fiberstore.

Image 2.4GHz Speed 5.8GHz Speed CPU Antenna Gain
AP-S300 ap-s300 300 Mbps No 533 MHz 2x3dBi
AP-D1200 ap-d1200 300 Mbps 867 Mbps 650 MHz 4x3dBi
AP-D1750 ap-d1750 450 Mbps 1300 Mbps 720 MHz 6x3dBi
Conclusion

This article is to give you some advice on how to choose a wireless access point. Well, when you decide to buy one, remember the tips mentioned above including standards, dual band or single band, spatial streams. The most suitable is the best. A reliable vendor is also important. Hope this article can help you find your desirable wireless AP.

Fiber Splitter for FTTH Applications

Passive optical network (PON) has been widely applied in the construction of FTTH (fiber to the home). With PON architecture, network service providers can send the signal to multiple users through a single optical fiber, which can help them save great costs. To build the PON architecture, optical fiber splitter is necessary.

What Is Fiber Splitter?

The fiber splitter is a passive component specially designed for PON networks. Fiber splitter is generally a two-way passive equipment with one or two input ports and several output ports (from 2 to 64). Fiber splitter is used to split the optical signal into several outputs by a certain ratio. If the ratio of a splitter is 1×8 , then the signal will be divided into 8 fiber optic lights by equal ratio and each beam is 1/8 of the original source. The splitter can be designed for a specific wavelength, or works with wavelengths (from 1260 nm to 1620 nm) commonly used in optical transmission. Since fiber splitter is a passive device, it can provide high reliability for FTTH network. Based on the production principle, fiber splitters include Planar Lightwave Circuit (PLC) and Fused Bionic Taper (FBT).

PLC splitters are produced by planar technology. PLC splitters use silica optical waveguide technology to distribute optical signals from central office to multiple premise locations. The output ports of PLC splitters can be at most 64. This type of splitters is mainly used for network with more users.

The Structure of PLC splitters

Internal Structure

The following figure shows a PLC splitter. The optical fiber is splitted into 32 outputs. PLC chip is made of silica glass embedded with optical waveguide. The waveguide has three branches of optical channels. When the light guided through the channels, it is equally divided into multiple lights (up to 64) and transmitted via output ports.

1x32-plc-splitter

Outside Configuration

Bare splitter is the basic component of PLC fiber splitter. For better protection of the fragile fiber and optimized use, PLC splitters are often equipped with loose tube, connector and covering box. PLC splitters are made in several different configurations, including ABS, LGX box, Mini Plug-in type, Tray type, 1U Rack mount, etc. For example, 1RU rack mount PLC splitter (as shown in the figure below) is designed for high density fiber optical distribution networks. It can provide super optical performance and fast installation. This splitter is preassembled and fibers are terminated with SC connectors. It’s ready for immediate installation.

rack-mount-plc-spllitter

FBT splitters are made by connecting the optical fibers at high temperature and pressure. When the fiber coats are melted and connected, fiber cores get close to each other. Then two or more optical fibers are bound together and put on a fused taper fiber device. Fibers are drawn out according to the output ratio from one single fiber as the input. FBT splitters are mostly used for passive networks where the split configuration is smaller.

PLC Splitters From FS.COM

Fiberstore offers a wide range of PLC splitters that can be configured with 1xN and 2xN. Our splitters are designed for different applications, configurations including LGX, ABS box with pigtail, bare, blockless, rack mount package and so on.

Port Configuration Package Style Fiber Diameter
(Input/output)
Connector (Input/output) Pigtail Length
1×2 Steel tube, bare fiber 250μm None 1.5m
1×4 Mini module 900μm SC APC/UPC 2.0m
1×8 Pigtailed ABS box 2.00mm LC APC/UPC 3.0m
1×16 Mini plugged-in 3.0mm FC APC/UPC Customized
1×32 LGX ST APC/UPC
1×64 Splice Tray Type Customized
2×16 Rack mount
Conclusion

Fiber splitter is an economical solution for PON architecture deployment in FTTH network. It can offer high performance and reliability against the harsh environment conditions. Besides, the small sized splitter is easy for installation and flexible for future network reconfiguration. Therefore, it’s a wise choice to use fiber splitter for building FTTH network.

Save Cost by Using BiDi Transceivers

As usual, optical transceivers such as SFP or SFP+ use two fibers to transmit data between switches. One fiber is used to transmit data to the network equipment and the other fiber is utilized to receive the data. As to the transceiver modules of high speed data rate like QSFP-40G-SR4 and QSFP-40G-ESR4, they need more fibers. Is there any technology allowing transceivers to transmit and receive through one single optical fiber or two fibers for QSFP+?

What Is BiDi Transceiver?

The answer is yes. And that kind of transceiver is called BiDi transceiver. Bidi (Bi–Directional) transceiver is also known as WDM transceiver, because it applies wavelength division multiplexing (WDM) couplers, also called diplexers, which combine and separate data transmitted over a single fiber based on the wavelengths of the light.

BiDi Transceiver Advantage

Compared with traditional transceiver modules, BiDi transceivers can cut your cost on fiber cabling infrastructure by requiring fewer fiber cables, reducing the number of fiber patch panel ports and saving fiber cable management space. Based on the obvious advantages, you should deploy BiDi transceivers in your network. Here will recommend you several kinds of BiDi transceivers of 1Gbps, 10Gbps and 40Gbps.

BiDi Transceiver Categories

BiDi SFP transceivers transmit and receive optical signal through a single fiber on the wavelengths of 1310 nm & 1490 nm, 1310 nm & 1550 nm, 1490nm & 1550 nm. BiDi SFPs include the supportable data rate of 100Mbps and 1000Mbps. Take the Cisco GLC-BX-U compatible 1000BASE-BX-U BiDi SFP as an example. The wavelengths of the BiDi SFP are 1310 nm and 1490 nm. It can support the link lengths of 10 km over LC simplex fiber patch cable. As shown in the following figure, a pair of Cisco GLC-BX-U compatible BiDi SFPs are linked via a single LC simplex fiber patch cable to build the direct connection of two Cisco Catalyst 4948E-F switches.

cisco-glc-bx-u

Bidi SFP+ transceiver is enhanced SFP designed to support 10Gbps data rate with link lengths up to 80 km over one fiber. It uses WDM technology sharing 1270 nm & 1330 nm. Take a look at the figure below. It’s about the direct connection for 10G BiDi SFP+ in room wiring. The two Cisco SFP-10G-BXU-I compatible 10GBASE-BX10-U SFP+ transceivers are plugged into Cisco Nexus 9396PX switches. The connection is achieved by using an LC simplex fiber patch cable. It’s a simplest and cost-effective way to build 10 Gigabit Ethernet connectivity for data center.

cisco-sfp-10g-bxu-i

BiDi QSFP+

40G BiDi QSFP+ transceiver is specially designed for high density data center. With QSFP+ BiDi transceivers, you can get 40Gbps network over 10Gbps cable. In this way, you don’t need to replace all 10G two-fiber patch cables with 8-fiber MTP/MPO patch cable if you need network upgrade. In Figure 3, we use Cisco QSFP-40G-SR-BD compatible 40GBASE-SR BiDi transceivers for the direct connection of two switches. Instead of applying 40G MTP patch cable, we can just plug the common LC-LC fiber patch cable into the transceivers to get 40Gbps network. It saves you lots of costs.

cisco-qsfp-40g-sr-bd

Warm Tips: When you buy a BiDi transceiver, you may notice wavelengths are labeled on the BiDi transceivers like 1270nm-TX/1330nm-RX or 1270nm-RX/1330nm-TX. From this perspective, you can see this type of transceivers should be used 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.

Summary

BiDi transceivers may be more expensive than common transceiver modules, but they can save you the cost on fiber cables from the long run. Fiberstore offers BiDi transceivers of various data rates which are highly compatible with some famous brands. If you plan to purchase BiDi transceivers for building or upgrading your network, you can visit our site www.fs.com.

What Should You Know About Fibre Channel?

Before Fibre Channel appears, SCSI (small computer system interface) was used as the transmission interface between servers and clustered storage devices. But as the high speed demands keep increasing, Fibre Channel replaces SCSI inevitably due to its higher transmission data rate, flexibility, and long distance. This article is going to introduce you some details about Fibre Channel.

What Is Fibre Channel?

Fibre Channel, short for FC, is a technology for transmitting data between computer devices at data rate of 1, 2, 4, 8, 16, 128 Gbps. It’s mainly used in storage area networks (SAN) in commercial data centers. It’s useful for connecting computer servers to shared storage devices and for interconnecting storage controllers and drives.

Fibre Channel Transceivers

Except optical fiber cable, Fibre Channel transceiver is the other vital equipment to connect the Fibre Channel network in data centers. It provides the interface between Fibre Channel systems and the optical fibers of the SAN. FS.COM offers SFPs and SFP+s that are compatible with Fibre Channel. Fiberstore Fibre Channel SFPs support the distance up to 80km and the data rate of 2G/4G. As to our Fibre Channel SFP+ transceivers, they can support the data rate up to 8Gbps and 10Gbps. In Fiberstore, you can also find some compatible brands of FC transceivers including Cisco, Juniper, Brocade, HPE, etc. What’s more, all these modules have been tested to assure 100% compatible. For your information, the following table shows some hot FC transceivers for 2G/4G and 8G/10G network applications.

Model Description
37656 2G Fibre Channel SFP 1310nm 10km DOM Transceiver
15376 Cisco DS-SFP-FC8G-ER Compatible 8G Fibre Channel SFP+ 1550nm 40km DOM Transceiver
15231 Cisco DS-SFP-FC8G-SW Compatible 8G Fibre Channel SFP+ 850nm 150m DOM Transceiver
33293 HPE (ex QLogic) AJ718A Compatible 8G Fibre Channel SFP+ 850nm 150m DOM Transceiver
39630 HPE (ex Brocade) AJ716B Compatible 8G Fibre Channel SFP+ 850nm 150m DOM Transceiver
35932 Brocade XBR-000163 Compatible 8G Fibre Channel SFP+ 850nm 150m DOM Transceiver
fibre-channel-sfp-sfp-plus
Transfer to High Speed Fibre Channel

However, as the need for high-bandwidth never stops increasing, the data rate of 2G, 4G or even 8G can’t meet the high speed requirements. So many data centers move to higher Fibre Channel standards, for example, 16G Fibre Channel. 16G FC links increase the network speed twice as 8G FC and 40% faster than 10G FC. The transition to 16G FC makes data transfer smoother, quicker and cost-effective from the good side. But from the other side, the transition still faces some challenges. There might be some data communication error rates that may affect the network performance. And the physics of 16G FC can possibly bring some new restrictions on fiber cabling and transceiver modules. Therefore, before starting to transfer to higher speed Fibre Channel infrastructure, you should better follow the tips listed below.

First, cleaning issue. In fiber optics connection, contamination is thought as a big problem which may lead to link failure. So you should clean all the transceiver modules, connectors and other cable junctions to ensure there is no contamination in the fiber optic connection. Some fiber testers and cleaning tools are necessary for your cleaning work.

Second, analyze the optical power budget between transmit and receiver ports. It requires that the power margin (transmit power minus power loss during the data transmission through the cable) should be more than the receiver power of the optical transceivers. At the same time, it also should meet the FC protocol specification.

Third, measure the light level on the transmitting side and receiving side. You can use suitable fiber optical light source or optical power meter to measure the power level on critical links. If the power level were not in the right station, check whether the cable length is suitable or cable bend radius reaches the maximum. Then you are suggested to purchase customized bend insensitive fiber cable for your special use.

Summary

Fibre Channel is commonly used for the connection of SAN in enterprise storage. You can find 2G/4G FC SFPs, 8G/10G FC SFP+ modules and matching fiber patch cables from FS.COM. If you need to upgrade your Fibre Channel network to 16G or even higher, remember the above tips and make sure the 16G FC are compatible with 4G FC and 8G FC.