Cable Testers used in Network

by Fiber-MART.COM

What is a Cable Tester? A cable tester is an electronic device used to verify the electrical connections in a cable or other wired assembly. Sometimes we also call it Network Cable Tester, because it is usually used in LAN Network.

 

There are many different types of cable testers, each able to test a specific type of cable or wire (some may be able to test several different types of cables or wires). The cable tester can test whether a cable or wire is set up properly, connected to the appropriate source points, and if the communication strength between the source and destination is strong enough to serve its intended purpose. Here is an example of a cable tester made in fiber-mart.

 

Its model is PN-8108, a Multifunction Network Cable Tester. This tester is very easy to operate for prevent and solve cable installation problem. It can widely be used for a number of applications such as cable connection sequence, length, user jumper and cable connection continuity and determine any open circuit, short circuit, jumper or cross-talk interference.

 

For computers, one of the most common types of cable testers used is for testing Cat5, Cat5e, and Cat6 network cables. Because so many different types of data can be transmitted over a network cable, it is important that the network cable connects properly between the computer and server. It is also important to ensure the signal strength between computers and servers is adequate for transmitting data and that there is no interference from outside sources that could cause a loss of data or decrease in signal strength. A cable tester can test for these factors and help to ensure the network cables connections are correct and will work for the intended purpose.

 

fiber-mart supplies many kinds of LAN Network Cable Testers, which are a kind of convenient and comprehensive tools for network professionals. Network Cable Tester is always being used to test LAN Datacom and Telecom cables. Network Cable Line Tester can find all problems associated with testing such faults as opens, shorts, cable integrity and it also find cable length of individual cables or distance to a fault, and its powerful and user-friendly features enable network installers to accurately check pin configurations of various voice and data communication cables.

 

Except Network Cable Testers, fiber-mart also offers many kinds of fiber optic tester. There are OTDR Testers, ADSL Testers, CCTV Security Testers, and Telephone Line Testers here.

 

Telephone Line Tester is a new kind of line fault tester with safety and multi-functions capabilities. Besides the functions as a common Telephone Line Tester, it also has the functions of high voltage protection and dangerous voltage warning. Such a phone line tester is used for detecting either digital or analog phone systems as well as the line polarity. Telephone line testers are good for both personal and professional use. fiber-mart supplies some mini phone line testers and other general telephone line testers. The importance that you should know is they are the cheapest and best performance products in fiber optic network.

Fiber Patch Cable Selection Guide for 40G QSFP+ Transceivers

by Fiber-MART.COM

Numerous things need to be planned and designed for 40G migration. Whether the switches can support such a high speed Ethernet? Which kind of optical transceiver work best on the switches? Which optical transceiver is more cost-saving? Although most servers provided today can support 40G and 40G QSFP+ transceiver (Quad Small Form-factor Pluggable transceiver) are considered to be the most economic and effective transceivers for 40G migration, new problem still arises.

 

Patch Cords Matters to 40G

No matter how advanced the switches are, they all need to be connected together to form the whole 40G transmission network. To accomplish the connections between these switches, patch cords are usually linked to fiber optic transceivers which are plugged in Ethernet switches (as shown in the following picture). 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.

 

Selecting Patch Cords for 40G QSFP+ Transceivers

Patch cords selection is a big issue to 40G 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 should be taken into account when selecting patch cords for 40G QSFP+ transceivers, which are cable type, connector type and switch port.

 

Cable Type

 

Performances of optical signals with different wavelengths are often quite different. Even optical signals with the same wavelength perform totally different when they run through different fiber optic cables. Thus, the selection of the cable type is essential.

 

A typical question our customer asked when buying a fiber optical patch cords for 40G QSFP+ transceiver can illustrate this point clearly. Can a 40GBASE universal QSFP+ transceiver working on wavelength of 850nm be used with OM1 patch cords? The answer is yes, but not suggested. Why? As the optical signal transmission distance gets shorter as 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-SR4 and 40GBASE-LR4. (SR stands for short-reach and LR stands for long reach). The latter is suggested for 40G transmission over single-mode fiber in long distance up to 10km. The former is for 40G transmission in short distance over multimode fiber—OM3 (up to 100 meters) and OM4 (up to 150 meters). OM3 and OM4, which are usually aqua-colored, are accepted economic solutions for 40G in short distance with lower insertion loss and higher bandwidth.

 

Connector Type

 

The connector type of the patch cords should depend on the interface of 40G QSFP+ transceiver. Currently there are two interfaces commonly adopted by 40G QSFP+ transceiver which 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.

 

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 to achieve the 40G transmission, thus 4 pairs of fibers are used and the 12-fiber MTP connectors can provide a time-save and stable solution for 40G QSFP+ transceivers. However, for multi-fiber connection, polarity should be considered for the selection of the patch cord. Here provide another article named “Understanding Polarity in MPO System” specifically explained MTP patch cords polarity for your reference.

 

However, to meet the market needs, 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. When it comes to 40G, network flexibility becomes an urgent issue which is closely related with applications. Right selection of patch cords for 40G QSFP+ transceiver can increase the network flexibility largely and effectively. Here offer two most common examples in 40G applications. One is 40G QSFP+ to 40G QSFP+ cabling, the other one is 40G QSFP+ to SFP+ cabling.

 

For distance up to 100m, the 40GBASE-SR4 QSFP+ transceiver can be used with OM3 fiber patch cable attached with a MPO one each end.

For distance up to 150m, the 40GBASE-SR4 QSFP+ transceiver can be used with OM4 fiber patch cable attached with a MPO one each end.

For distance up to 10km, the 40GBASE-LR4 QSFP+ transceiver can be used with single-mode fiber with LC connectors. The picture above shows the transmission of 40GBASE-LR4 QSFP+ transceiver with LC connector over single-mode fiber.

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.

 

Conclusion

Cable type, connector type and switch port in selecting the right patch cords for 40G QSFP+ transceivers are necessary and important. 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, these three factors are far from enough. Planning and designing takes a lot of time and may not achieve results good enough. However, fiber-mart can solve your problems with professional one-stop service including the cost-effective and reliable network designing and 40G products.

What's fiber to the x (FTTx)

Fiber to the x (FTTx) is a collective term for various optical fiber delivery topologies that are categorized according to where the fiber terminates.

 

Optical fiber is already used for long-distance parts of the network, but metal cabling has traditionally been used for the stretches from the telecom facilities to the customer. FTTx deployments cover varying amounts of that last distance.

 

In an FTTN (fiber to the node or fiber to the neighbourhood) deployment, the optical fiber terminates in a cabinet which may be as much as a few miles from the customer premises. The cabling from the street cabinet to customer premises is usually copper.

 

 

In an FTTC (fiber to the curb or fiber to the cabinet) deployment, optical cabling usually terminates within 300 yards of the customer premises.

 

 

In an FTTB (fiber to the building or fiber to the basement) deployment, optical cabling terminates at the building, which is typically multi-unit. Delivery of service to individual units from the terminus may be through any of a number of methods.

 

 

In an FTTH (fiber to the home) deployment, optical cabling terminates at the individual home or business.

 

 

FTTP (fiber to the premises) is used to encompass both FTTH and FTTB deployments or is sometimes used to indicate that a particular fiber network includes both homes and businesses.

The FTTH Councils of Europe, North America and Asia-Pacific have agreed upon definitions for FTTH and FTTB. Standard definitions of the other terms have not yet been established.

 

The table below provides a graphical comparison of the most common FTTx topologies:

 

 

The table above was created by Wikipedia user Riick and is published under the terms of a Creative Commons Attribution-Share Alike license.

Multimode Fiber Optic Cable

Today, multimode fiber optic systems are lagging behind singlemode systems in terms of growth. In addition to supporting high data throughput, singlemode systems are attractive because they are easy to upgrade and help to "future proof" installations.  Nonetheless, multimode fiber still gets plenty of coverage in any fiber optic cable guide.  Why? Because multimode is still the fiber of choice for many applications.

 

For example, multimode fiber optic cable is well suited for systems that have short fiber optic links, such as Local Area Networks (LANs) and Storage Area Networks (SANs).

 

Multimode Advantages

Multimode fiber optic cable and components are less expensive and easier to work with than their singlemode counterparts. This is due largely to the fact that the multimode fiber core is larger, and alignment tolerances are much less critical than they are for singlemode fiber. 

 

Like singlemode, multimode fiber provides high bandwidth at high speeds, but transmission is limited to shorter distances than singlemode. (In longer cable runs, the multiple paths of light in a multimode fiber tend to create signal distortion).

 

Standard multimode cable is made of glass fibers, usually 50-to-100 micron in diameter (most common is 62.5).  Multimode cable is also available as low-cost Plastic Optical Fiber (POF), which offers performance similar to glass cable for very short runs.

 

Singlemode Advantages

Generally, singlemode cable provides less signal attenuation, higher transmissions speeds, and up to 50 times greater transmission distance than multimode cable.  Singlemode cable can transmit data at terabits per second over 100km without requiring re-amplification of the signal.

 

Singlemode fiber typically has a diameter of only 8.3 to 10 microns, which is much narrower than multimode fiber which is usually 50 to 100 microns in diameter. The small core of a singlemode fiber allows for the propagation of only one light wave, so there is no possibility of distortion due to overlapping light pulses. Also, singlemode is more stable than multimode for systems that have branching devices, such as couplers.

 

Which to Choose?

When deciding whether to use multimode or singlemode fiber, a lot depends on a system's current and future bandwidth requirements. As a general guide, think of multimode bit rate as being limited to 100Mbps over distances up to 40km, with shorter links allowing for bit rates up to 10Gbps.

 

If your system is comprised of relatively short fiber links and bandwidth requirements are not expected to exceed multimode capacity over the system's lifetime, then multimode may be the logical choice. It is less expensive to purchase, install and maintain.

FIBER-MART(Fiber-MART.COM), based in HongKong & U.S., a worldwide leading supplier in fiber optic network, fttx, fiber cabling & connectivity, fiber testing, fiber splicing, fiber polishing & integrated network solutions. Devoting on the research & development, design, manufacture, and fiber connectivity network solutions for carriers, ISPs, content providers and networks, has always engaged in high-performance and innovation.