Know More About Router for Computer Networks

It is undeniable that the Internet narrows the distance between each other, making the world smaller. Benefiting from high speed information network, we are able to know what’s happening around the world without going out, as long as you have a computer which can get access to the Internet. How can your computer get access to the Internet? Just plug one end of Ethernet cable into the network port. But where is the other end of Ethernet cable plugged into? The answer is router, which is the topic of this article. Keeping reading, and you will know more about it.

Overview of Router

From the external appearance, router is a small plastic or metal box-shaped electronic device. It features a number of physical ports on the front or back of the unit, such as WAN (wide area network) port, LAN (local area network) port and power input port. Also, there are some LED lights to display device status. As the WAN port and LAN port are rj45 interface, they are often connected with ri45 patch cable, such as cat5e ethernet cable, cat6 ethernet cable, Cat7 ethernet cable. Traditional routers are designed to join together multiple local area networks (LANs) with a wide area network (WAN), so there are four LAN ports (LAN1-4) and one WAN port on router. In addition, the WAN port is connected with modem or switch while the LAN port is connected with computer. To have a better understanding of router’s outer structure, Here is figure for you.

router
Working Principle of Router

In technical terms, a router is a Layer 3 network gateway device, meaning that it connects two or more networks and that the router operates at the network layer of the OSI model. Routers contain a processor (CPU), several kinds of digital memory, and input-output (I/O) interfaces. They function as special-purpose computers, one that does not require a keyboard or display. The router’s memory stores an embedded operating system (O/S). Compared to general-purpose OS products like Microsoft Windows or Apple Mac OS, router operating systems limit what kind of applications can be run on them and also need much smaller amounts of storage space. Examples of popular router operating systems include Cisco Internetwork Operating System (IOS) and DD-WRT. These operating systems are manufactured into a binary firmware image and are commonly called router firmware. By maintaining configuration information in a part of memory called the routing table, routers also can filter both incoming or outgoing traffic based on the addresses of senders and receivers. In simple terms, router serves as intermediate destinations for network traffic. It receives incoming network packets, looks inside each packet to identify the source and target network addresses, then forwards these packets where needed to ensure the data reaches its final destination.

Conclusion

In our daily life, router can be seen everywhere. In fact, there are different kinds of routers for specific applications, such as home broadband router for home network, edge router for an ISP network, subscriber edge router for subscriber’s network and so on. Learning about some basic knowledge about router helps to understand different functions of different router and this will save time on solving problem especially when we come across the situation where router break down. Here I recommend two of the top router seller: TP-LINK and NETGEAR. Though FS.COM does not provide router, you can find high quality ethernet cable here at low price, such as 1m cat5e ethernet cable is US$ 0.91, 1m cat6 ethernet cable is US$ 1.00 and 1m Cat7 ethernet cable is US$ 12.00. For more details, please visit our site.

All About Cat7

Network has become an indispensable part of our daily life. Many homes and businesses today deploy network with either a wired network connection or a wireless connection, and these two network connection methods have their own advantages: wired connection is typically faster than wireless connection and has lower latency; while wireless connection makes it easier to get access to the network from nearly any convenient location. As network technology has kept stepping forward, these two types of network hardware also continue to advance, satisfying the requirements of users. Take wired connection for example, now a newer cable category is Cat7 ethernet cable. This article will focus on Cat7 and share the advantages and disadvantages of Cat7 cabling.

Overview of Cat7

Cat7 ethernet cable is not currently recognized by TIA/EIA, but it is designed to support 10G Ethernet with distance up to 100 meters. It can offer transmission frequencies of up to 600 MHz, which is 6 times larger than Cat5e and 2.4 times larger than Cat6. The Cat7 ethernet cable contains four twisted copper wire pairs, just like the earlier standards, and shielding has been added for individual wire pairs and the cable as a whole. In addition, Cat7 ethernet cable is terminated with GG45 (GigaGate45) connector, which is still compatible cat5e cable and cat6 cable with RJ45 connector.

Cat7 ethernet cable

Advantages And Disadvantages of Cat7 Cabling

Though Cat7 ethernet cable is a newer cable category, it is not the best choice for all network deployment. Why? Keeping reading and you will find the answer in the following part.

Advantages
  • Cat7 has higher bandwidth of up to 600 MHz, which is 6 times larger than Cat5e (100 MHz) and 2.4 times larger than Cat6 (250 MHz).
  • Cat 7 has an overall shield as well as individual shielding of every pair. It performs better to protect against outside interference. Therefore, it is suitable for installing in strong RFI & EMI environment.
  • Cat7 is thicker, more bulky, and more difficult to bend.
  • Cat7 is regarded as the most durable cable and has a longer lifespan of fifteen years than cat5e cable and cat6 cable.
  • Cat7 is compatible with preceding Ethernet cable standards like Cat5e and Cat6. as a result, users can move Cat5e cable or Cat6 cable from existing copper based LAN and install Cat7 without having to change the existing electronics.
Disadvantages
  • Cat7 ethernet cable is not currently recognized by TIA/EIA. It is not a solid, established industry standard.
  • Cat7 is very heavy. Individual pair and overall shielding increases the overall weight and size of Cat7, which makes it not an job for Cat7 cabling. Larger & stronger pathway and more stringent bend radius (100 mm or 4 inch) are required.
  • Cat7 is more expensive. Individual pair and overall shielding also means higher labor costs and more work towards cable termination.
  • Cat7 cabling may cause ground loop problems. If both ends of the cable are connected to ground, it will lead to ground loops which are a major cause of noise, hum, and interference in audio, video, and computer systems. They can also create an electric shock hazard, since ostensibly “grounded” parts of the equipment, which are often accessible to users, are not at ground potential.
Conclusion

For home network deployment, it is not a great option, because it is more expensive and Cat7 cabling is complicated. However, Cat7 is suitable for the place where needs high speed data transmission and is high EMI environment. Therefore, in order to get a successful network deployment, you have to make a careful plan, be familiar with environment, confirm the requirement of network deployment and choose the right transmission media. FS.COM offers the best and most versatile copper cables including Cat5e, Cat6 and Cat7 products. For more details, please visit our site.

Originally published at: http://www.fiber-optical-networking.com/all-about-cat7.html

Introduction to Server Power Cord

The power cord is an indispensable unit to support the work of power supply. Connecting the servers and PDU (power distribution unit), server power cord plays an important role in ensuring good electricity supply. However, the standard for the connector type and voltage level of power cord are different in different countries. To make the network system work with high performance level, it is necessary to choose a suitable power cord. This article will give an introduction to server power cord to help you make the choice.

Overview of Power Cord

Although there are many different types of power cords used around the word, the structures of them are similar. In general, power cord consists of three parts: plug, cord and receptacle. The IEC60320 power cord and NEMA power cord are the most commonly seen types. The former one is commonly seen in US, while the latter one is widely used in North America and other countries that use the standards set by the NEMA. The following figure shows c13 to c14 power cord, nema 5 15p to c13 power cord, c14 to c15 power cord and nema 5 15p to c15 power cord, which are the most popular one power cable manufacturers like Dell, HP and IBM.

power cord
Low Density System

For low density system, it is very easy to install the power cord. The server needs to use a country-specific power cord for direct connection to a facility AC feed. However, server availability goals can require providing redundant AC power to the server in the form of a redundant AC bus or a UPS. As the following figure shows, server in figure A uses c13 to c14 power cord, and server in figure B uses nema 5 15p to c13 power cord.

power cord in low density system
Medium Density System

For medium density system, the installation of power cord is a little complex than that of low density system. To achieve an effective power connection, different types and other accessories are may be needed. As the following figure shows, power connections are achieved using modular PDH, extension bars and c13 to c14 power cord assemblies. For server which contains hot-pluggable fans accessible by sliding the chassis out on rails, the power cord connecting to the server must have adequate length and slack to allow chassis movement while staying connected and powered up.

power cord in medium density system
High Density System

For high density system, the length of power cord can be short since cable movement is less frequent. The following figure shows three kinds of methods to connect enclosures to AC power. The first one in the upper area shows that the c13 to c14 power cord is used to connect a single-supply server to a vertical mount PDU, which is suitable for lower-density installations. The second one in the central area shows the use of C13 x4-to-C20 fixed cord extension bars, which is a recommended method for extreme-density installations using redundant power supplies. The last one shows the use of a C13 x2-to-C20 Y-cable assembly, which is recommended for connecting a server with dual 1200-watt power supplies directly to a PDU core with C19 outlets.

power cord in high density system
Conclusion

Power cord serves as an important bridge in the network device power supply system. I hope after reading this article, you can have a better understanding of server power cord. FS.COM offers different types of IEC power cords, NEMA power cords, and jumper cords for server rack equipment with different colors and different lengths. If you want to know more details, please visit our website.

Comparison Between Singlemode QSFP28 and Multimode QSFP28

Fiber optic transceiver, as an important optical component, is widely used for transmitting and receiving optical signals to facilitate communication. To meet the increasing demand for higher speed and bandwidth, fiber optic transceiver has continued to evolve, from SFP, 10G SFP+, 40G QSFP+ to 100G CFP and QSFP28. Among them, 100G QSFP28 transceiver is now very popular on the market. We know that fiber optic transceiver can be divided into singlemode transceiver and multimode transceiver, so this article will make a comparison between singlemode QSFP28 and multimode QSFP28.

Singlemode QSFP28

Singlemode QSFP28 is usually used with singlemode fiber. We know that the core of singlemode fiber is smaller and the laser wavelength is narrower. Therefore, singlemode fiber permits the transmission of signals at higher bandwidth thus facilitating the data transmission at a longer distance. Singlemode QSFP28 mainly works at 1310nm wavelength and is commonly used for long distance data transmission. There are different types of singlemode QSFP28 which can achieve different data transmission distance, such as 100GBASE-PSM4 QSFP28 can support 500 meters, 100GBASE-CWDM4 QSFP28 can support 2 kilometers and 100GBASE-LR4 QSFP28 can support 10 kilometers. And there are some other differences among them. The 100GBASE-PSM4 QSFP28 is designed with 12-fiber MTP connector interface, so it is used with MTP cable; while 100GBASE-CWDM4 QSFP28 and 100GBASE-LR4 QSFP28 are structured with duplex LC connector interface, so they are used with duplex LC patch cable.

singlemode QSFP28 and singlemode fiber

Multimode QSFP28

Multimode QSFP28 is usually used with multimode fiber. The core of multimode fiber is much bigger and multimode fiber usually uses a wider wavelength of light. In addition, it permits the use of inexpensive LED light sources and alignment of the connectors with a coupling that is less critical than that of singlemode fiber. As a result, fiber optics used over multimode fiber have a higher capability to gather light from the laser and are cheaper. Multimode QSFP28 mostly works at 850nm wavelength and is used for short optical link length, like 70 meters over OM3 and 100 meters over OM4. There is only one type of multimode QSFP28—100GBASE-SR4 QSFP28. It has 12-fiber MTP connector interface, so it has to be used with MTP cable.

100GBASE-SR4 QSFP28

Comparison Between Singlemode QSFP28 and Multimode QSFP28

From the above, we can clearly see some differences between singlemode QSFP28 and multimode QSFP28. This part will make a summary from several aspects.

Transmission media: Singlemode QSFP28 works with singlemode fiber while multimode QSFP28 works with multimode fiber. It is noted that 100GBASE-PSM4 QSFP28 is used with singleomde MTP cable and 100GBASE-SR4 QSFP28 is used with multimode MTP cable; while 100GBASE-CWDM4 QSFP28 and 100GBASE-LR4 QSFP28 are used with singlemode duplex LC patch cable.

Transmission distance: Singlemode QSFP28 can reach 500 meters, 2 kilometers and 10 kilometers while multimode QSFP28 is able to support 100 meters optical link.

Power consumption: Multimode QSFP28 consumes less power than singlemode QSFP28, which is an important consideration especially when assessing the cost of powering and cooling a data center.

Cost: Singlemode QSFP28 are nearly two or three times higher in price when compared to multimode QSFP28. Because singlemode fiber requires more expensive laser sources and costs more to make as it is more “fragile”.

Compatibility issue: When it comes to issues dealing with compatibility, the two types of QSFP28 transceivers are not compatible due to the differences in fiber core size and wavelengths.

Conclusion

This article makes a comparison between singlemode QSFP28 and multimode QSFP28. Both of them have their own advantages in data center applications. As for which one to choose, it all depends on your specific requirement of deployment. FS.COM, as a professional optical products supplier, offers various QSFP28 optics to meet customers’ diverse needs. If you have any need, please visit www.fs.com for more detailed information.

Cabling Solutions for 100G CFP/120G CXP

The step for higher capacity and throughput in data centers has never stopped and the 100G/120G Ethernet network has been widely applied. However, it is not an easy job to upgrade existing 10G/40G equipment to meet the requirement of 100G/120G Ethernet network. Is there any cabling solution for smooth migration from 10G/40G to 100G/120G? Of course, there is. This article will take multimode 100G CFP/120G CXP transceiver for example and introduce some cabling solutions to you.

100G/120G to 100G/120G

We know that 100G CFP/120G CXP transceiver is designed with 24 fiber MTP/MPO connector interface (10 Tx and 10 Rx with each lane providing 10Gbps, leaving 4 channels unused). Therefore, it is usually used with 24 fiber MTP/MPO cable. The following figure shows that two 100G CFP/120G CXP transceivers are separately plugged into 100G port on two 100G switches. And then the two 100G CFP/120G CXP transceivers can be directly connected by a 24 fiber MTP/MPO trunk cable. This the simplest cabling solution for 100G/120G to 100G/120G connectivity.

100G 120G to 100G 120G

100G/120G to 10G

By using the 24 fiber MPO to 12 LC duplex harness cable, the 100G/120G to 10G connection can be achieved. However, for the optical link completed by 100G CFP transceiver and ten SFP+ transceivers, there are two LC duplex legs are not used; for 120G to 10G connection, one 120G CXP transceiver and twelve 10G SFP+ transceivers are connected which realize 100% fiber utilization. In this cabling solution, three 10G switch may be needed to satisfied the requirement of at least twelve 10G SFP+ ports. As the following figures shows, 100G CFP/120G CXP transceiver is plugged into 100G port on 100G switch on one side, while ten or twelve 10G SFP+ transceivers are plugged into 10G ports on 10G switches on the other side. Then the 100G CFP/120G CXP transceiver and ten or twelve 10G SFP+ transceivers can be connected by the 24 fiber MPO to 12 LC duplex harness cable. This is also the simplest cabling solution for 100G/120G to 10G connectivity.

100G 120G to 10G

With the use of MTP/MPO fiber optic patch panel, 100G to 10G connection can also be reachable. From the figure below we can see that one end of 24 fiber MTP/MPO trunk cable is plugged into 100G CFP transceiver on the 100G switch, while the other end is plugged into MTP ports on the rear of the MTP/MPO fiber optic patch panel. Then the one end of ten LC duplex patch cables are plugged into the LC ports on the front of the MTP/MPO fiber optic patch panel and the other end of cables are connected with ten 10G SFP+ transceivers which are plugged into 10G ports on 10G switches. This cabling solution offers ultimate flexibility in allowing connectivity to any row, rack or shelf. In addition, the MTP/MPO fiber optic patch panel can support up to eight groups of this 100G to 10x10G transmission.

100G to 10G

There is a hybrid link for 120G CXP transceiver, 40G QSFP+ transceiver and 10G SFP+ transceiver. We can use the 1×3 MTP/MPO conversion harness cable to connect 120G CXP transceiver on 100G switch and three 40G QSFP+ transceivers on 40G switches. Then another three 40G QSFP+ transceivers on the 40G switches can be connected with the twelve 10G SFP+ transceivers on 10G switches by three 12fiber MTP-LC fanout cables.

120G to 40G to 10G

Conclusion

As 100G/120G Ethernet network has becomes more and more popular, various types of 100G CFP/120G CXP transceivers are available on the market. This article has illustrated some cabling solutions for migration from 10G/40G to 100G/120G and it is not difficult to find that MTP components are commonly used in these cabling solutions. I hope after reading this article, you can learn something useful.

A Closer Look at 40G QSFP+ SR4 Transceiver

As 40G network has been widely applied in today’s data center cabling system, 40G QSFP+ transceivers gain great popularity among data center managers. And for short data transmission distance, 40G QSFP+ SR4 transceiver is preferred. This article is going to focus on 40G QSFP+ SR4 transceiver and share several cabling solutions for 40G QSFP+ SR4 with you.

Overview of 40G QSFP+ SR4 Transceiver

40G QSFP+ SR4 transceiver is a parallel fiber optic transceiver which means it uses four fibers for transmitting and four fibers for receiving at the same time. Designed with MTP/MPO interface, 40G QSFP+ SR4 transceiver is used together with multimode fiber, such as OM3 and OM4. Working on wavelength of 850 nm, 40G QSFP+ SR4 transceiver can support 40G fiber optic transmission with the link length up to 100 meters over OM3 fiber and 150 meters over OM4 fiber. For application, 40G QSFP+ SR4 transceiver can be used for 10G to 40G and 40G to 40G connections. Here is a figure of 40G QSFP+ SR4 transceiver for you.

40G QSFP+ SR4 transceiver

10G to 40G Connection

Since 40G QSFP+ SR4 transceiver uses four independent full-duplex transmit and receiver channels, the 40G optical signal can be split into four 10G optic signals. Therefore, we can increase the fiber count at the 10G distribution end to realize 10G to 40G connection. As the following figure shows, we can use 12f MPO trunk cable and fiber enclosure. Four 10G SFP+ SR transceivers are inserted into 10G ports on one side, while one 40G QSFP+ SR4 transceiver is inserted into 40G port on the other side. Then the four 10G SFP+ SR transceivers are connected with four duplex LC patch cables which are plugged into LC ports on the front side of MPO fiber cassette inside the fiber enclosure, and the 40G QSFP+ SR4 transceiver is connected with 12f MPO trunk cable which is plugged into MTP/MPO port on the rear of MPO fiber cassette. Finally, the whole optical link is completed.

40G QSFP+ SR4 transceiver for 10G to 40G connectionA

We can also use MPO to LC fanout and MTP fiber patch enclosure which includes MTP fiber adapter panels. This cabling solution is similar to the previous one, but the difference is that the four 10G SFP+ SR transceivers are connected with MPO to LC fanout which is plugged into MTP/MPO port on the MTP fiber patch enclosure. The scenario is shown in the following figure.

40G QSFP+ SR4 transceiver for 10G to 40G connectionB

40G to 40G Connection

The following figure shows the simplest scenario for 40G to 40G connection. Two 40G QSFP+ SR4 transceivers are separately inserted into two 40G switches. Then the two 40G QSFP+ SR4 transceivers are connected by 12f MPO trunk cable.

40G QSFP+ SR4 transceiver for 40G to 40G connectionA

We can also use MTP fiber patch enclosure to achieve better cable management and higher density cabling. The scenario is shown in the following figure. With the use of MTP fiber enclosure, cable management for 40G to 40G connection could be easier. A 48-port 1U rack mount MTP fiber patch enclosure includes up to four 12-port MTP fiber adapter panels with MPO MTP fiber optical adapters on it, here is a figure for you.

40G QSFP+ SR4 transceiver for 40G to 40G connectionB

Conclusion

Designed with parallel transmission mode, 40G QSFP+ SR4 transceiver has a wide range of cabling applications with great flexibility. The cabling solutions mentioned above are just several commonly used ones. As for detailed cabling solutions for 40QSFP+ SR4 transceiver, it is suggested to depend on the practical applications and cabling environments. I hope after reading this article, you can learn more about 40G QSFP+ SR4 transceiver.

Do Not Forget to Clean the Fiber Optic Connector

We know that fiber optic connector plays an important role in connecting optical cable with other optical components. As an indispensable component in cable installation, the cleanliness of fiber optic connector needs attention. Since it is impossible to guarantee that fiber optic connector does not get dirty, do not forget to clean the fiber optic connector. This article is going to introduce two tools for your fiber optic connector cleaning—one-click cleaner and cassette cleaner.

Overview of One-Click Cleaner And Cassette Cleaner

Both of one-click cleaner and cassette cleaner utilize dry cleaning without any alcohol and other harsh chemicals. However, the one-click cleaner is applicable for cleaning both connector in adapter and exposed connector with one-push action, while the cassette cleaner is only applicable for exposed connector. In addition, one-click cleaner has three types for LC/MU, SC/ST/FC and MTP/MPO connector respectively, while cassette cleaner is used for MTP apc connector or MPO apc connector. In the following part, the cleaning procedures of them will be shown.

Cleaning Procedures

1.25mm LC/MU And 2.5mm SC/ST/FC One-click Cleaner

structure of 1.25mm LC MU one-click cleaner

The structure and procedures of these two types of one-click cleaner are similar, so take 1.25mm one-click cleaner for example.

For Connector in Adapter

  1. Remove the guide cap and cover from the cleaner tip.
  2. Insert cleaner tip into the adapter.
  3. Push the cleaner body to start cleaning the connector end face until you hear an audible “click” sound which indicates the cleaning process is finished.

For Exposed Connector

  1. Open the cover of the guide cap.
  2. Insert cleaner tip into the connector.
  3. Push the cleaner body to start cleaning the connector end face until you hear an audible “click” sound which indicates the cleaning process is finished.
MTP/MPO One-click Cleaner
MTP MPO one-click cleaner

For Connector in Adapter

  1. Pull off the guide cap.
  2. Insert the cleaning tool into the bulkhead and turn the cleaning wheel backwards until click two times.

For Exposed Connector

  1. Carefully pull out the guide cap cover.
  2. Insert the patch cord into the cleaning tool, apply slight pressure and turn the cleaning wheel backward until click two times.
Cassette Cleaner
cassette cleaner
  1. Remove connector dust cover.
  2. Select the appropriate cleaner for male/female.
  3. For MTP female connector or MPO female connector, use the cleaning brush and fluid to remove any debris from the pin holes.
  4. Depress the lever so that a fresh area of cleaning cloth is exposed.
  5. Position the ferrule against the cloth so that the fibers are in contact with the cleaning material. In the case of angled connectors, the ferrule will need to be adjusted accordingly.
  6. Wipe the connector in the direction shown on the cassette.
  7. Release the grip to seal off the cleaning cloth.
  8. Let the ferrule air-dry before inspecting with a 200xmicroscope.
  9. If still contaminated repeat all steps once again.
  10. Ensure that the connector does not touch any hard surfaces.

Note: Do not move connector back and forth. Connector is to be moved in only the direction of the arrows on the cleaner.

Conclusion

To ensure high level optical performance, it is critical to keep fiber optic connector clean and free of contaminants. One-click cleaner and cassette cleaner are being highly recommended as practical tools for cleaning optical fiber end-face without the use of alcohol. FS.COM provides various fiber optic cleaning tools. If you want to know more details, please visit our site.