How to Understand PoE and PoE+ Switches

by www.fiber-mart.com

Power-over-Ethernet (PoE) is the technology that allows network switches to transmit power and data through an Ethernet cable at the same time. PoE switch streamlines both of the processes of powering and providing data to the device, which makes it a straightforward and reliable device for home network and small enterprise application. This article describes two types of PoE (PoE and PoE+) that are commonly used and provides information on what types of PoE can be used according to different applications.

 

PoE Versus non-PoE Technology

 

Power over Ethernet technology facilitates powering a device (such as an IP phone, IP Surveillance Camera, or NVR recorder) over the same Ethernet cable as the data traffic. Figure 1 shows an Ethernet Network with IP camera, PoE Switch, NVR recorder and Wireless router. Compared to non-PoE devices, PoE devices feature with flexibility that allow you to easily place endpoints anywhere in the business, even places where it might be difficult to run a power outlet.

 

PoE Versus PoE+ Technology

 

PoE was first defined in the IEEE 802.3af standard. PoE devices utilize PoE standard, which can provide up to 15.4W of DC power to each port. A later standard, IEEE 802.3at, known as PoE+, increases the amount of power to 30 W. The major difference between 802.3af (PoE) and 802.3at (PoE+) is that PoE+ PSEs can provide almost twice as much power over a single Ethernet cable.

 

Can PoE+ devices work over PoE Ports, Or vice versa? The PoE+ standard provides support for legacy PoE devices, meaning that an IEEE 802.3af powered device (PD) can operate normally when connected to IEEE 802.3at (PoE+) power sourcing equipment (PSE). PoE+ PSEs can supply power to both PoE and PoE+ PDs. However, as PoE+ PDs require more power than PoE PSEs can provide, PoE PSEs can only supply power to PoE PDs.

 

PoE Switch Or PoE+ Switch

 

Whether to use PoE or PoE+ switch for your network, you need to calculate your required power budget carefully for all of the PDs you plan to connect. PoE+ IEEE 802.3at devices can supply a maximum of 30 watts per port, while PoE IEEE 802.3af devices can supply a maximum of 15.4 watts per port. However, some power is always lost over the length of the cable, and more power is lost over longer cable runs. The minimum guaranteed power available at the PD is 12.95 watts per port for PoE and 25.5 watts per port for PoE+.

 

For most endpoints, 802.3af is sufficient but there are devices, such as Video phones or Access Points with multiple radios, which have higher power needs. It’s important to point out that there are other PoE standards currently being developed that will deliver even high levels of power for future applications. Optical switches have a power budget set aside for running the switch itself, and also an amount of power dedicated for PoE endpoints.

 

 

fiber-mart PoE Switches

 

fiber-mart POE switches can supply power to network equipment such as weather-proof IP cameras, AP and IP telephones. They are featured with high flexibility, high stability and high resistance to electromagnetic interference. All fiber-mart PoE switches come with a one-year limited warranty, including any quality problems during the free maintenance. The following above shows 1G PoE Switch with 24 1000BASE-T and 4 SFP ports.

Introduction to Semiconductor Optical Amplifier

by www.fiber-mart.com

Optical amplifier, with the introduction in 1990s, conquered the regenerator technology and opened doors to the WDM technology. It is mainly used to amplify an optical signal directly, without the need to first convert it to an electrical signal. There are many types of optical amplifiers, namely Raman amplifiers, erbium doped-fiber amplifiers (EDFAs), and semiconductor optical amplifier (SOA). This article will make a clearer introduction to SOA amplifier, and analyze its advantages and disadvantages.

 

The Basics of Semiconductor Optical Amplifier (SOA)

 

SOA optical amplifiers use the semiconductor as the gain medium, which are designed to be used in general applications to increase optical launch power to compensate for loss of other optical devices. Semiconductor optical amplifiers are often adopted in telecommunication systems in the form of fiber-pigtailed components, operating at signal wavelengths between 0.85 µm and 1.6 µm and generating gains of up to 30 dB. Semiconductor optical amplifier, available in 1310nm, 1400nm, 1500nm, 1600nm wavelength, can be used with singlemode or polarization maintaining fiber input/output.

 

Key Points of SOA Amplifier

 

1310 nm, 1400 nm, 1550 nm and 1610 nm wavelength selectable

High fiber-to-fiber gain of 20 dB

Up to 16 dBm output

1 MHz with 10 ns pulse width (optional)

PM Panda fiber input/output (optional)

Similar to lasers, but with non-reflecting ends and broad wavelength emission

Incoming optical signal stimulates emission of light at its own wavelength

Process continues through cavity to amplify signal

Working principle of SOA amplifier

 

The basic working principle of a SOA is the same as a semiconductor laser but without feedback. SOAs amplify incident light through simulated emission. When the light traveling through the active region, it causes these electrons to lose energy in the form of photons and get back to the ground state. Those stimulated photons have the same wavelength as the optical signal, thus amplifying the optical signal.

 

SOA Over EFDA in DWDM Networks

 

As the solution below, 120km Metro Networks by Using an SOA amplifier. You may wonder why not use EDFA in the above networks.

 

Theoretically, SOA optical amplifiers are not comparable with EDFA in the terms of performance. The noise figure of SOA optical amplifier is typically higher, the gain bandwidth can be similar, SOAs exhibit much stronger nonlinear distortions in the form of self-phase modulation and four-wave mixing. Yet, the semiconductor optical amplifier is of small size and electrical pumped, which is often less expensive than EDFA. Additionally, SOA can be run with a low power laser.

 

How to Choose SOA Optical Amplifier?

 

When selecting SOA amplifier, you have to check the every detailed parameter in the product data sheet. But, seriously, do you understand it? No, please read the following part.

 

The key parameters used to characterize a SOA amplifier are gain, gain bandwidth, saturation output power and noise.

 

Gain is the factor by which the input signal is amplified and is measured as the ratio of output power to input power (in dB). A higher gain results in higher output optical signal.

 

Gain bandwidth defines the range of bandwidth where the amplification functions. A wide gain bandwidth is desirable to amplify a wide range of signal wavelengths.

 

Saturation output power is the maximum output power attainable after amplification beyond which no amplification is reached. It is important that the SOA has a high power saturation level to remain in the linear working region and to have higher dynamic range.

 

Noise defines the undesired signal within the signal bandwidth which arises due to physical processing in the amplifier. A parameter called noise figure is used to measure the impact of noise which is typically around 5dB.

 

Conclusion

 

SOA amplifier is the economic, high-performance solution for long-hual WDM networks. SOA amplifier, due to its features, can be used in Booster and in-line amplification, optical network, general purpose test and measurement and fiber sensing. However, it also has its limit. In semiconductor optical amplifiers, electron-hole recombination occurs which will affect the performance of the whole line. fiber-mart offers EDFA, SOA, Raman optical amplifiers of excellent quality and price. 

400G CFP8 PAM4 & 400GBASE-SR16 NRZ Transceiver Modules

by www.fiber-mart.com

With the price of 100G QSFP28 optics and CFP form factors (CFP module/CFP2/CFP4) dropping down in 2017, 100G technology is becoming more and more popular among data center managers and IT pros in order to cope with the ever-lasting bandwidth needs. However, 100G is not the finish line. CFP multimode source agreement (MSA) demonstrated CFP8 (16X 25 Gb/s) form factor for 400 Gigabit Ethernet at OFC 2017. Although CFP8 module is still in development, it is assured to be popular in the near future. Therefore, this article will have a clearer introduction to 400G CFP8 PAM4 and NRZ modules, and compare with the former CFP modules and 400G CDFP.

 

Introduction to 400GbE CFP8 Modules

 

CFP8 module is the latest developing CFP from factor version, which supports eight times and four times the bandwidth density of CFP and CFP2 form factors, respectively. The CFP8 interface supports up to 16 different lanes in each direction with nominal signaling rates of 25Gb/s or 26Gb/s per lane, and either NRZ or PAM4 signaling. As the above image shows, CFP8 is approximately the size of a CFP2 optics. This interface has been generally specified to allow for 16 x 25 Gb/s and 8 x 50 Gb/s mode.

 

400G CFP8 FR8 and LR8 Transceivers with PAM4 Technology

 

CFP8 PAM4 optics, compliant with IEEE 802.3bs 400GBASE-FR8 & LR8 electrical interface specifications, offers higher receiver bandwidth capacity for reach up to 2km and 10km. The 400GBASE-FR8 & LR8 consumes less than half the power per GB compared to a 100G CFP4 msa solution. CFP8 optics uses LC duplex fiber cables.

 

The PAM4 stands for pulse amplitude modulation with four levels. Instead of driving the laser to generate one of the two output amplitudes, like NRZ, PAM4 technology generates four different amplitude levels, meaning a network based on PAM-4 can send twice as much data as an NRZ version.

 

CFP8 400GBASE-SR16 with NRZ Technology

 

CFP8 400GBASE-SR16 modules focus on non-return to zero (NRZ) signal modulation Scheme. To use an analogy, it means you’re sending signals in the most simple format: “light on” and “light off.” A ‘1” is transmitted as pulse of light whereas ‘0” is no light output. Based on the currently available fast VCSEL light sources only achieving data rates of 25G, sixteen channels must transmit in parallel to create a 400G data stream.

 

Due to the design simplicity NRZ, the modulation format of choice for all data rates up to 25Gb/s. 400GBASE-SR16 CFP8 transceivers requires 16 fiber pairs to support a total of 400Gb/s with MPO multimode cables.

 

What’s New With CFP8 Module?

 

A CFP8 module is a hot pluggable module. Compared with the former modules, the control and status reporting functions between a host and a CFP8 module use non-data control and status reporting pins on the 124-pin connector. There are three Hardware Control pins, two Hardware Alarm pins, and four pins dedicated to the MDIO interface.

 

Compared to CFP2/CFP4 MSA Optics

 

CFP8 is the proposed CFP8 from factor by MSA member companies. It maintains the large size of CFP form factor (nearly the size of CFP2, larger than CFP4 MSA modules), but supports 4x100G i.e. 4x the CFP2. Besides this, CFP8 uses less power than the former CFP form factor modules. There are 400GBASE-SR16 for parallel MMF 16x25G NRZ, and 400GBase-FR8/LR8 duplex SMF 8x50G PAM4 WDM.

 

CFP8 Vs. CDFP

 

CFP8 is not the first released 16x25G= 400G modules, but CDFP. 400G CDFP module (CD=400 in Latin), is the four generation CFP form factor. Providing a high level of integration, performance and long-term reliability, the CDFP 400 Gbps interface is available in short- and long-body versions. The specifications are compatible for use with direct attach cables, active optical cables, and connectorized optical modules. The CDFP module will support:

 

5 meter direct attach cables

100 meter multimode fiber

500 meter parallel single‐mode fiber

2 kilometers of duplex single‐mode fiber

The compact modules are well suited for low power applications using copper, VCSEL or silicon photonics based technology. They also targeted InfiniBand EDR hydra cables and 128GFC applications but so far little market segment pick up. Though relatively new with 2014 and 2015 rev releases, CDFP may be short lived due to the smaller more efficient developing set of CFP8 solutions.

 

Latest Trend With 400 Gb/s in the Industry

 

While 400 GbE standard is still a few years away, the need for 400 Gb/s interfaces is here today. The CDFP form factor is already being used in proprietary interfaces to interconnect high performance servers and will soon be used to interconnect switch and router chassis. 400G CFP8 FR8/LR8 PAM4 and 400GBASE-SR16 modules had been displayed at OFC 2017. Finisar, Fujitsu, and oclaro, etc MSA member enterprises will introduce low profile 400G modules in a short period.

 

These proprietary chassis interconnects have always been massively parallel and will continue because they provide the massive bandwidth needed to interconnect equipment so that multiple chassis perform as one big chassis. While 16 lanes is a fairly wide interface, multiple applications need the maximum amount of bandwidth that can only be provided by many parallel lanes running at the fastest speed available. It seem that CFP8 with the same 16 MPO connectors has much potential than CDFP modules. fiber-mart.COM offers a large stock MSA-compliant optical transceivers, including 100G CFP/CFP2/CFP4 MSA, CXP, and QSFP28 transceiver modules. We will keep in path with the informative world, and provide the best services & telecom products to all of our customers.

WHY FIBER OPTIC NETWORK IS HIGH SPEED INTERNET CONNECTION

by www.fiber-mart.com

Broadband connection has gained a lot of popularity over the last few years in both urban and rural areas. There is a massive rise in this service amongst businesses where entrepreneurs want to promote their services and products over the web in quick and convenient manner. Due to high speed internet connection, downloading the files, uploading the video or images and chatting has become quite easy. Users don’t find any issue of slow speed nowadays due to latest technology and connection. In last couple of year, fiber optic network has emerged as one of the best connections to provide high speed access to the web world.

 

Dial-up, Wireless, Cable and Fiber Optics are some of the techniques to allow users to access the web world. But when it comes to access web world in high speed manner then fiber optics is the best connection which has also changed the way people using internet in the past. This connection has very thin fibers built of glass that transmit the data and files through a fiber optic network. As the glass fibers go via low level of reduction and hindrance, the connection becomes highly effective for telecommunication. Now let’s discuss why it is seen as the high speed connection for residents and commercial places:

 

Fastest Speed: It is a fastest broadband connection that provides ultra fast speed up to 10,000 Mbps. With the use of innovative methods and latest technologies, the connection promises to give users high speed round the clock allowing them to send emails and files in ultra fast speed. When it comes to compare fiber optics to cable connection & Digital subscriber line (DSL), then one will find that sending data or files is much quicker with fiber network even during peak hours. From live streaming to downloading video, everything becomes faster and easier with this fiber connection.

 

More Reliability: Fiber Optics Network is also quite reliable as compared to cable connection & Digital subscriber line (DSL). Even during the power outrage, the connection remains intact as it is made of glass that required no electricity. It is also difficult for others to hack the network as mostly the system installed in the home of users.

 

Temperature Fluctuation: The best thing with fiber connection is that it resists more temperature fluctuations as compared to cable and Digital subscriber line (DSL). On the hand, fiber optics network can be submerged in water as well without facing any network issue.

 

Cost: It is obvious that when you are getting better services then you have to pay little more. Fiber Optics network is also little expensive as compared to other ordinary connections. But when users are getting high speed then paying little more can’t be a bad decision. Today businesses are running over the internet and it is only successful when they have high speed and better connectivity round the clock.  

 

So keeping in mind all the points, it is not wrong to say that Fiber Optics Network is best for those who want high speed connection with safe and strong connectivity.

WHY IS FIBER OPTIC CONNECTION BENEFICIAL FOR BUSINESS?

by www.fiber-mart.com

There is no doubt that internet has become a necessity of a successful business. You can’t think life without the web world. From institution to entertainment, people of all age group spend their maximum time on internet. With change of time, demands of users have also increased significantly. Earlier most of the users thought to get an economical connection with manageable speed. People did not think too much about speed earlier but nowadays, speed has become the first preference of the users. They want a connection having ultra fast speed and strong connectivity. No matter in which part of the world you are living, if you are an internet freaky then you will surely want a high speed internet connection.

 

Running a successful business needs a reliable broadband connection in the present competitive world. It is important for a smooth workflow at the workplace. It has noticed that a number of time users need to upload a heavy file which takes a lot of time making them frustrated. It not just makes users annoying but also hampers the productivity of the business. That’s the reason many technologies have introduced to booth the speed for a smooth web access. Among all the available technologies, fiber optic is one of the most advanced technologies in broadband industry. Fiber has changed the way business was dealt the earlier.'

'

Advantages of Fiber Optic Connection

 

Lighting fast speed

Excellent connectivity

More reliability

Bigger and larger bandwidth

Symmetric speed

BOON OF USING FIBER OPTIC CABLES OVER COPPER CABLES

by www.fiber-mart.com

Everyone knows that approx.. an year ago we use copper cables while using the internet connection of any brand. The service providers come up with copper cable to install the internet connection and provide the required service to them. But at present time, fiber optic cable is in demand. The users are quite happy with its performance as it rarely gets out of connection. On the other hand, it also gives a good speed to the user in comparison to the copper cables. Let’s discuss some other best advantages of fiber optic cable over the copper cables.

 

Greater BandwidthThe 

 

copper cable has the capacity to handle greater bandwidth as originally it was designed for voice transmission and have a limited bandwidth. So, now it is used as a greater bandwidth device. It carries more data than copper cables at the same diameter. Within the fiber cable group, only single mode fiber can delivers up to twice the multimode fiber. So, users are fine with what they are availing.

 

Faster SpeedsThe 

 

fiber cables carry light to transmit data. This enables the cable to carry diverse signals at speeds that are slower than the speed of light which is faster than cat5 and cat6 copper cables. Therefore the speed this cable is higher than the copper cable.

 

Longer Distances

 

When it comes to long distance, this cable never disappoints as cables generally works on the basis of wavelength, network, distance and it performs well in each of these areas. It carries signals much faster than the traditional foot limitations upto 328ft. It carries data upto 25 miles.

 

Better ReliabilityBe 

 

it any weather, fiber cable is immune to temperature changes. Weather doesn’t hamper the connectivity of this cable as like other traditional cables. And it does not even carry electric current so user must be stressed free with electromagnetic interference (EMI) that can interrupt data transmission.

 

Thinner and Sturdier

 

In comparison to any other cable, this cable is thinner, sturdier and light in weight. It is less prone to damage and breakage.

 

More Flexibility for the Future

 

According to the demand and usage, the media converters enable the user to incorporate fiber into existing networks. The converters enhance the Ethernet connection over fiber optic by extending the UTP. Modern panels are designed to meet the current needs and provide the flexibility for future needs. The panels are comprises of variety of cassettes for different types of fiber patch cables.

 

Low Cost

 

If the user gets its ownership, then he or she will realize that in initial days the rate of fiber optic cable is a bit expensive, but its reliability, durability and speed makes it worth it. And after some days of use, it automatically becomes affordable as there are a number of packages are given to the user to choose the most affordable one.

 

Each of these advantages of fiber optic cable makes it best among all other traditional internet connections. 

WHY FIBER OPTIC NETWORK IS HIGH SPEED INTERNET CONNECTION

Broadband connection has gained a lot of popularity over the last few years in both urban and rural areas. There is a massive rise in this service amongst businesses where entrepreneurs want to promote their services and products over the web in quick and convenient manner. Due to high speed internet connection, downloading the files, uploading the video or images and chatting has become quite easy. Users don’t find any issue of slow speed nowadays due to latest technology and connection. In last couple of year, fiber optic network has emerged as one of the best connections to provide high speed access to the web world.

 

Dial-up, Wireless, Cable and Fiber Optics are some of the techniques to allow users to access the web world. But when it comes to access web world in high speed manner then fiber optics is the best connection which has also changed the way people using internet in the past. This connection has very thin fibers built of glass that transmit the data and files through a fiber optic network. As the glass fibers go via low level of reduction and hindrance, the connection becomes highly effective for telecommunication. Now let’s discuss why it is seen as the high speed connection for residents and commercial places:

 

Fastest Speed: It is a fastest broadband connection that provides ultra fast speed up to 10,000 Mbps. With the use of innovative methods and latest technologies, the connection promises to give users high speed round the clock allowing them to send emails and files in ultra fast speed. When it comes to compare fiber optics to cable connection & Digital subscriber line (DSL), then one will find that sending data or files is much quicker with fiber network even during peak hours. From live streaming to downloading video, everything becomes faster and easier with this fiber connection.

 

More Reliability: Fiber Optics Network is also quite reliable as compared to cable connection & Digital subscriber line (DSL). Even during the power outrage, the connection remains intact as it is made of glass that required no electricity. It is also difficult for others to hack the network as mostly the system installed in the home of users.

 

Temperature Fluctuation: The best thing with fiber connection is that it resists more temperature fluctuations as compared to cable and Digital subscriber line (DSL). On the hand, fiber optics network can be submerged in water as well without facing any network issue.

 

Cost: It is obvious that when you are getting better services then you have to pay little more. Fiber Optics network is also little expensive as compared to other ordinary connections. But when users are getting high speed then paying little more can’t be a bad decision. Today businesses are running over the internet and it is only successful when they have high speed and better connectivity round the clock.  

 

So keeping in mind all the points, it is not wrong to say that Fiber Optics Network is best for those who want high speed connection with safe and strong connectivity.

WHY IS FIBER OPTIC CONNECTION BENEFICIAL FOR BUSINESS?

There is no doubt that internet has become a necessity of a successful business. You can’t think life without the web world. From institution to entertainment, people of all age group spend their maximum time on internet. With change of time, demands of users have also increased significantly. Earlier most of the users thought to get an economical connection with manageable speed. People did not think too much about speed earlier but nowadays, speed has become the first preference of the users. They want a connection having ultra fast speed and strong connectivity. No matter in which part of the world you are living, if you are an internet freaky then you will surely want a high speed internet connection.

 

Running a successful business needs a reliable broadband connection in the present competitive world. It is important for a smooth workflow at the workplace. It has noticed that a number of time users need to upload a heavy file which takes a lot of time making them frustrated. It not just makes users annoying but also hampers the productivity of the business. That’s the reason many technologies have introduced to booth the speed for a smooth web access. Among all the available technologies, fiber optic is one of the most advanced technologies in broadband industry. Fiber has changed the way business was dealt the earlier.'

'

Advantages of Fiber Optic Connection

 

Lighting fast speed

Excellent connectivity

More reliability

Bigger and larger bandwidth

Symmetric speed

BOON OF USING FIBER OPTIC CABLES OVER COPPER CABLES

Everyone knows that approx.. an year ago we use copper cables while using the internet connection of any brand. The service providers come up with copper cable to install the internet connection and provide the required service to them. But at present time, fiber optic cable is in demand. The users are quite happy with its performance as it rarely gets out of connection. On the other hand, it also gives a good speed to the user in comparison to the copper cables. Let’s discuss some other best advantages of fiber optic cable over the copper cables.

 

Greater BandwidthThe 

 

copper cable has the capacity to handle greater bandwidth as originally it was designed for voice transmission and have a limited bandwidth. So, now it is used as a greater bandwidth device. It carries more data than copper cables at the same diameter. Within the fiber cable group, only single mode fiber can delivers up to twice the multimode fiber. So, users are fine with what they are availing.

 

Faster SpeedsThe 

 

fiber cables carry light to transmit data. This enables the cable to carry diverse signals at speeds that are slower than the speed of light which is faster than cat5 and cat6 copper cables. Therefore the speed this cable is higher than the copper cable.

 

Longer Distances

 

When it comes to long distance, this cable never disappoints as cables generally works on the basis of wavelength, network, distance and it performs well in each of these areas. It carries signals much faster than the traditional foot limitations upto 328ft. It carries data upto 25 miles.

 

Better ReliabilityBe 

 

it any weather, fiber cable is immune to temperature changes. Weather doesn’t hamper the connectivity of this cable as like other traditional cables. And it does not even carry electric current so user must be stressed free with electromagnetic interference (EMI) that can interrupt data transmission.

 

Thinner and Sturdier

 

In comparison to any other cable, this cable is thinner, sturdier and light in weight. It is less prone to damage and breakage.

 

More Flexibility for the Future

 

According to the demand and usage, the media converters enable the user to incorporate fiber into existing networks. The converters enhance the Ethernet connection over fiber optic by extending the UTP. Modern panels are designed to meet the current needs and provide the flexibility for future needs. The panels are comprises of variety of cassettes for different types of fiber patch cables.

 

Low Cost

 

If the user gets its ownership, then he or she will realize that in initial days the rate of fiber optic cable is a bit expensive, but its reliability, durability and speed makes it worth it. And after some days of use, it automatically becomes affordable as there are a number of packages are given to the user to choose the most affordable one.

 

Each of these advantages of fiber optic cable makes it best among all other traditional internet connections. 

Can I Use QSFP+ Optics on the QSFP28 Port?

100G Ethernet will have a larger share of network equipment market in 2017, according to Infonetics Research. But we can’t neglect the fact that 100G technology and relevant optics are still under development. Users who plan to layout 100G network for long-hual infrastructures usually met some problems. For example, currently, the qsfp28 optics on the market can only support up to 10 km (QSFP28 100GBASE-LR4) with WDM technology, which means you have to buy the extra expensive WDM devices. For applications beyond 10km, QSFP28 optical transceivers cannot reach it. Therefore, users have to use 40G QSFP+ optics on 100G switches. But here comes a problem, can I use the QSFP+ optics on the QSFP28 port of the 100G switch? If this is okay, can I use the QSFP28 modules on the QSFP+ port? This article discusses the feasibility of this solution and provides a foundational guidance of how to configure the 100G switches.

 

For Most Switches, QSFP+ Can Be Used on QSFP28 Port

 

As we all know that QSFP28 transceivers have the same form factor as the QSFP optical modules. The former has just 4 electrical lanes that can be used as a 4x10GbE, 4x25GbE, while the latter supports 40G ( 4x10G). So from all of this information, a QSFP28 module breaks out into either 4x25G or 4x10G lanes, which depends on the transceiver used. This is the same case with the SFP28 transceivers that accept SFP+ transceivers and run at the lower 10G speed.

 

A 100G QSFP28 port can generally take either a QSFP+ or QSFP28 optics. If the QSFP28 optics support 25G lanes, then it can operate 4x25G breakout, 2x50G breakout or 1x100G (no breakout). The QSFP+ optic supports 10G lanes, so it can run 4x10GE or 1x40GE. If you use the QSFP transceivers in QSFP28 port, keep in mind that you have both single-mode and multimode (SR/LR) optical transceivers and twinax/AOC options that are available.

 

In all Cases, QSFP28 Optics Cannot Be Used on QSFP+ Port

 

SFP+ can’t auto-negotiate to support SFP module, similarly QSFP28 modules can not be used on the QSFP port, either. There is the rule about mixing optical transceivers with different speed—it basically comes down to the optic and the port, vice versa. Both ends of the two modules have to match and form factor needs to match as well. Additionally, port speed needs to be equal or greater than the optic used.

 

How to Configure 100G Switch

 

For those who are not familiar with how to do the port configuration, you can have a look at the following part.

 

How do you change 100G QSFP ports to support QSFP+ 40GbE transceivers?

Configure the desired speed as 40G:

(config)# interface Ethernet1/1

(config-if-Et1/1)# speed forced 40gfull

 

How do you change 100G QSFP ports to support 4x10GbE mode using a QSFP+ transceiver?

Configure the desired speed as 10G:

(config)# interface Ethernet1/1 – 4

(config-if-Et1/1-4)# speed forced 10000full

 

How do you change 100G QSFP ports from 100GbE mode to 4x25G mode?

Configure the desired speed as 25G:

(config)# interface Ethernet1/1 – 4

(config-if-Et1/1-4)# speed forced 25gfull

 

How do you change 100G QSFP ports back to the default mode?

Configure the port to default mode:

(config)# interface Ethernet1/1-4

(config-if-Et1/1)# no speed

 

Note that if you have no experience in port configuration, it is advisable for you to consult your switch vendor in advance.

 

Conclusion

 

To sum up, QSFP+ modules can be used on the QSFP28 ports, but QSFP28 transceivers cannot transmit 100Gbps on the QSFP+ port. When using the QSFP optics on the QSFP28 port, don’t forget to configure your switch (follow the above instructions). To make sure the smooth network transmission, you need to ensure the connectors on both ends are the same and no manufacturer compatibility issue exists.

Das ABC des PON-Netzwerks: OLTs, ONUs, ONTs und ODNs

In den vergangenen Jahren legen Telekommunikationsunternehmen ihren Fokus immer stärker auf das Konzept des „Fiber to the Home“ (FTTH), wodurch sich die Technologien schnell und stetig weiterentwickeln. Es gibt zwei wichtige Arten von Systemen, die FTTH-Breitbandverbindungen ermöglichen: aktive optische Netzwerke (AON) und passive optische Netzwerke (PON). In diesem Beitrag stellen wir das ABC des PON-Netzwerks vor. Dieses umfasst die grundlegenden Komponenten und die zugehörige Technologie, einschließlich OLT, ONT, ONU und ODN.

 

Was ist ein passives optisches Netzwerk (PON)?

Ein passives optisches Netzwerk (PON) ist ein System, in dem Glasfaserkabel und Signale auf dem gesamten Weg oder dem Großteil des Weges zum Endnutzer zur Verfügung stehen. Je nachdem, wo das PON endet, kann das System als „Fiber to the Curb“ (FTTC), „Fiber to the Building“ (FTTB) oder „Fiber to the Home“ (FTTH) beschrieben werden. Der Unterschied zwischen WDM-PON vs GPON vs XG-PON.

 

Komponenten eines PON-Netzwerks

Ein PON besteht aus einem Optical Line Terminal (OLT) in einer lokalen Vermittlungsstelle und mehreren Optical Network Units (ONUs) in der Nähe der Endnutzer. Es gibt aktuell zwei große PON-Standards: Gigabit Passive Optical Network (GPON) und Ethernet Passive Optical Network (EPON). Aber egal um welche Art von PON-Netzwerk es sich handelt, besteht die gleiche grundlegende Topologiestruktur. Ein Gigabit Ethernet Passive Optical Network (GEPON) System besteht im Allgemeinen aus einem Optical Line Terminal (OLT) in der Vermittlungsstelle des Service Providers und mehreren Optical Network Units (ONUs) oder Optical Network Terminals (ONTs) in der Nähe der Endnutzer. Zusätzlich wird ein Optical Distribution Network (ODN) bei der Übertragung zwischen OLT und ONU/ONT verwendet.

 

Optical Line Terminal (OLT)

Der OLT ist eine Apparatur, die die L2/L3-Schalterfunktion im GEPON-System integriert. OLT-Geräte enthalten im Allgemeinen ein Rack, das Steuerungs- und Schaltermodul (CSM), das EPON Link-Modul und die PON-Card (ELM), Redundanzschutz, 48V-DC-Stromversorgungsmodule oder ein 110/220V-AC-Stromversorgungsmodul sowie einen Lüfter. PON-Card und Netzteil unterstützen meißt Hot-Swaps, während andere Module fest verbaut sind. Die Hauptfunktion von OLTs besteht darin, den Informationsfluss über das ODN von einer zentralen Vermittlungsstelle aus in beide Richtungen zu steuern. Die maximale Entfernung, die für die Übertragung über das ODN unterstützt wird, beträgt 20 km. OLT hat zwei Floating-Richtungen: Upstream (Abrufen und Verteilen verschiedener Arten von Daten- und Sprachverkehr von Nutzern) und Downstream (Abrufen von Daten-, Sprach- und Videoverkehr vom Metro-Netzwerk oder von einem Langstrecken-Netzwerk und Senden an alle ONT-Module innerhalb des ODN).

 

Optical Network Unit (ONU)

ONUs wandeln optische Signale, die über Glasfaser übertragen werden, in elektrische Signale um. Diese elektrischen Signale werden dann an einzelne Teilnehmer gesendet. Im Allgemeinen gibt es eine gewisse Entfernung oder ein separates Zugangsnetz zwischen ONU und den Räumlichkeiten des Endnutzers. Darüber hinaus können ONUs verschiedene Arten von Daten, die vom Kunden kommen, senden, aggregieren und pflegen („grooming“) und sie an den OLT senden. Grooming ist ein Prozess, in dem der Datenstrom optimiert und neu organisiert wird um effizienter bereitgestellt werden zu können. OLT unterstützt Bandbreitenzuweisung, die eine reibungslose Übertragung der Daten an das OLT ermöglicht, die normalerweise in Form von Paketen vom Kunden ankommen. ONU kann mit verschiedenen Methoden und Kabeltypen wie Twisted-Pair-Kupferdraht, Koaxialkabel, Glasfaser oder Wi-Fi verbunden werden.

 

Optical Network Terminal (ONT)

Im Wesentlichen sind ONTs dasselbe wie ONUs. ONT ist ein Begriff der ITU-T (International Telecommunication Union), während ONU ein Begriff der IEEE (Institute of Electrical and Electronics Engineers) ist. Sie beziehen sich beide auf die Anwenderseite im GEPON-System. In der Praxis gibt es je nach ihrem Standort jedoch gewisse Unterschiede zwischen ONTs und ONUs. ONTs sind in der Regel direkt vor Ort beim Kunden.

 

Optical Distribution Network (ODN)

Das ODN stellt das optische Übertragungsmedium für die physikalische Verbindung der ONUs zu den OLTs bereit. Die Reichweite beträgt 20 km oder mehr. Innerhalb des ODN arbeiten Glasfaserkabel, faseroptische Stecker, passive optische PON Splitter und Hilfiber-martkomponenten eng miteinander zusammen. Die ODN beinhaltet insbesondere fünf Segmente: die Zuführfaser (Feeder Fiber), den optischen Verteilerpunkt (Optical Distribution Point), die Verteilungsfaser (Distribution Fiber), den optischen Zugangspunkt (Optical Access Point) sowie Glasfaserendkabel (Drop Fiber). Die Zuführfaser verläuft vom optischen Verteiler-Rahmen (Optical Distribution Frame, ODF) in der Leitstelle (Central Office, CO) bis zu den Verteilerpunkten für die Fernabdeckung. Die Verteilungsfaser verläuft vom optischen Verteilerpunkt zum optischen Zugangspunkt und verteilt optische Faserverbindungen auf daneben liegende Bereiche. Glasfaserendkabel verbinden den optischen Zugangspunkt mit Nutzeranschlüssen (ONTs) und schließen somit die Glasfaserverbindung bis in den Benutzerhaushalt ab. Darüber hinaus ist das ODN der eigentliche Pfad für die PON-Datenübertragung und seine Qualität wirkt sich direkt auf die Leistung, Zuverlässigkeit und Skalierbarkeit des PON-Systems aus.

 

Die Vorteile und Nachteile der Glasfaserkabel

Aufgrund der unübertroffenen Vorteile von Lichtwellenleitern in der Telekommunikations- und Datenkommunikation steigt die Geschwindigkeit, da sie weniger Dämpfung, weniger anfällig für elektromagnetische Störungen (EMI), geringere Größe und größere Informationsübertragungskapazität sind. Die unaufhörliche Bandbreite erfordert andererseits auch ein signifikantes Wachstum der Glasfaseranforderungen. Lassen Sie uns einen Überblick über gängige Glasfaserkabeltypen geben, die Vorteile und Nachteile von Glasfaser erforschen und Tipps zur Auswahl von Glasfaserkabeln geben.

 

Was ist Lichtwellenleiter(LWL)-Kabel?

LWL-Kabel verwenden Lichtimpulse anstelle von elektrischen Impulsen, um Informationen zu übertragen, und liefern somit eine hundertmal höhere Bandbreite als herkömmliche elektrische Systeme. Glasfaserkabel können durch Ummantelung und Panzerung geschützt werden, um sie resistent gegen raue Umgebungsbedingungen zu machen. Daher ist es weit verbreitet in kommerziellen Unternehmen, Regierungen, Militär und vielen anderen Industrien für Sprach-, Video- und Datenübertragung. Im Allgemeinen gibt es drei Arten von Glasfaserkabeln: Singlemode-Glasfaserkabel, Multimode-Glasfasern und Kunststoff-Glasfasern (POF).

 

Gemeinsame Arten der Glasfaserkabel

In der Regel gibt es drei Arten der Glasfaserkabel: Singlemode, optische multimode und optische Faser aus Kunststoff (plastic optical fiber).

 

Glasfaserkabel Singlemode

Der “Modus” in Lichtwellenleitern bezieht sich auf den Weg, auf dem sich Licht bewegt. Fasern mit Singlemode haben einen kleineren Kerndurchmesser von 9 Mikron (8,3 Mikron, um genau zu sein) und erlauben nur eine einzige Wellenlänge und Weg für das Licht, was Lichtreflexionen stark verringert und die Dämpfung verringert. Singlemode-Glasfaserkabel ist etwas teurer als seine Multimode-Pendants, die oft in Netzwerkverbindungen über große Längen verwendet wird.

 

Glasfaserkabel Multimode

 

Lichtwellenleiter Multimode Kabel haben einen größeren Kerndurchmesser als Glasfaserkabel mit Singlemode, wodurch mehrere Wege und mehrere Lichtwellenlängen übertragen werden können. Optische Faser mit Multimode ist in zwei Größen erhältlich, 50 Mikron und 62,5 Mikron. Es wird häufig für kurze Entfernungen verwendet, einschließlich Patchkabelanwendungen wie Glasfaserverbindungen zum Desktop oder Patchpanel zu Geräte-, Daten- und Audio- / Videoanwendungen in LANs.

 

Optische Faser aus Kunststoff (POF)

 

POF ist eine optische Faser mit großem Stufenindex mit einem typischen Durchmesser von 1 mm. Die große Größe ermöglicht es, viel Licht von Quellen und Anschlüssen zu koppeln, die keine hohe Präzision erfordern. Typische Verbinderkosten betragen 10-20% so viel wie für Glasfasern und die Terminierung ist einfach. Da es aus Kunststoff ist, ist es haltbarer und kann in wenigen Minuten mit minimalen Werkzeugen und Schulungen installiert werden. Der Preis für optische Kunststoffkabel ist wettbewerbsfähiger und damit eine praktikable Option für Desktop-LAN-Verbindungen und kurze Verbindungen mit niedriger Geschwindigkeit.

 

Vorteile und Nachteile von Lichtleitkabel

Im Angesicht der Geschwindigkeits- und Bandbreitenvorteile ist die optische Faser über Kupferkabel. Näturlich enthält sie auch einige Nachteile. Hier sind Vor- und Nachteile von Glasfaserkabel.

 

Vorteile von LWL-Kabel

Größere Bandbreite & Schnellere Geschwindigkeit—LWL-Kabel unterstützt extrem hohe Bandbreite und Geschwindigkeit. Die Menge an Information, die pro Einheit von optischen Faserkabeln übertragen werden kann, ist der wichtigste Vorteil.

 

Billig—Mehrere Kilometer der Glasfaserkabel können billiger als äquivalente Kupferdrahtlängen hergestellt werden. Um den Marktanteil zu konkurrieren, würde der Preis mit zahlreichen Anbietern für optische Kabel sicher fallen.

 

Dünner und leichter—Die Glasfaser Patchkabel ist dünner und kann auf kleinere Durchmesser als Kupferdraht gezogen werden. Sie sind kleiner und leichter als ein vergleichbares Kupferkabel und eignen sich besser für Orte, an denen Platz eine Rolle spielt.

 

Höhere Tragfähigkeit—Da Glasfaser Patchkabel viel dünner als Kupferdrähte sind, können mehr Fasern zu einem Kabel mit gegebenem Durchmesser gebündelt werden. Dadurch können mehr Telefonleitungen über dasselbe Kabel oder mehrere Kanäle geleitet werden, um über das Kabel in Ihre Kabel-TV-Box zu gelangen.

 

Geringere Signalverschlechterung—Der Signalverlust in LWL-Patchkabel ist geringer als der in Kupferdraht.

 

Lichtsignale—Im Gegensatz zu elektrischen Signalen, die in Kupferdrähten übertragen werden, stören Lichtsignale von einer Faser nicht die von anderen Fasern im selben Faserkabel. Dies bedeutet klarere Telefongespräche oder TV-Empfang.

 

Lange Lebensspanne—Optische Fasern haben normalerweise eine längere Lebensdauer für mehr als 100 Jahre.

 

Nachteile der Glasfaser-Patchkabel

Eingeschränkte Anwendung—LWL-Kabel können nur auf dem Boden verwendet werden und es kann nicht den Boden verlassen oder mit der mobilen Kommunikation arbeiten.

 

Geringer Strom—Emittierende Lichtquellen sind auf geringe Leistung beschränkt. Obwohl Hochleistungssender zur Verfügung stehen, um die Stromversorgung zu verbessern, würde dies zusätzliche Kosten verursachen.

 

Zerbrechlichkeit—LWL-Patchkabel sind im Vergleich zu Kupferdrähten eher empfindlich und anfälliger für Beschädigungen. Sie sollten Lichtleiterkabel nicht verdrehen oder biegen.

 

Entfernung—Der Abstand zwischen Sender und Empfänger sollte kurz sein oder Repeater sind notwendig, um das Signal zu verstärken.

How to Understand PoE and PoE+ Switches

Power-over-Ethernet (PoE) is the technology that allows network switches to transmit power and data through an Ethernet cable at the same time. PoE switch streamlines both of the processes of powering and providing data to the device, which makes it a straightforward and reliable device for home network and small enterprise application. This article describes two types of PoE (PoE and PoE+) that are commonly used and provides information on what types of PoE can be used according to different applications.

 

PoE Versus non-PoE Technology

 

Power over Ethernet technology facilitates powering a device (such as an IP phone, IP Surveillance Camera, or NVR recorder) over the same Ethernet cable as the data traffic. Figure 1 shows an Ethernet Network with IP camera, PoE Switch, NVR recorder and Wireless router. Compared to non-PoE devices, PoE devices feature with flexibility that allow you to easily place endpoints anywhere in the business, even places where it might be difficult to run a power outlet.

 

PoE Versus PoE+ Technology

 

PoE was first defined in the IEEE 802.3af standard. PoE devices utilize PoE standard, which can provide up to 15.4W of DC power to each port. A later standard, IEEE 802.3at, known as PoE+, increases the amount of power to 30 W. The major difference between 802.3af (PoE) and 802.3at (PoE+) is that PoE+ PSEs can provide almost twice as much power over a single Ethernet cable.

 

Can PoE+ devices work over PoE Ports, Or vice versa? The PoE+ standard provides support for legacy PoE devices, meaning that an IEEE 802.3af powered device (PD) can operate normally when connected to IEEE 802.3at (PoE+) power sourcing equipment (PSE). PoE+ PSEs can supply power to both PoE and PoE+ PDs. However, as PoE+ PDs require more power than PoE PSEs can provide, PoE PSEs can only supply power to PoE PDs.

 

PoE Switch Or PoE+ Switch

 

Whether to use PoE or PoE+ switch for your network, you need to calculate your required power budget carefully for all of the PDs you plan to connect. PoE+ IEEE 802.3at devices can supply a maximum of 30 watts per port, while PoE IEEE 802.3af devices can supply a maximum of 15.4 watts per port. However, some power is always lost over the length of the cable, and more power is lost over longer cable runs. The minimum guaranteed power available at the PD is 12.95 watts per port for PoE and 25.5 watts per port for PoE+.

 

For most endpoints, 802.3af is sufficient but there are devices, such as Video phones or Access Points with multiple radios, which have higher power needs. It’s important to point out that there are other PoE standards currently being developed that will deliver even high levels of power for future applications. Optical switches have a power budget set aside for running the switch itself, and also an amount of power dedicated for PoE endpoints.

 

 

fiber-mart PoE Switches

 

fiber-mart POE switches can supply power to network equipment such as weather-proof IP cameras, AP and IP telephones. They are featured with high flexibility, high stability and high resistance to electromagnetic interference. All fiber-mart PoE switches come with a one-year limited warranty, including any quality problems during the free maintenance. The following above shows 1G PoE Switch with 24 1000BASE-T and 4 SFP ports.