How to Choose Fiber Optic Cable for 10G SFP+ Optical Transceiver?

How to choose fiber optic cables for 10G SFP+ transceivers? It seems like a dumb question for most of the fiber optic technicians. However, there are still some people, especially the green-hand network installers, may not know the compatibility between fiber optic cables and optical transceiver modules. Today, I want to make a clear illustration of how to choose the right transmission media (OS2/OM3/OM4/Cat6/Cat6a) for 10G SFP+ optical transceiver modules.

Overview of SFP+ Optical Transceiver Module

Before coming to the main part of this article, let’s first have a brief overview of the SFP+ optical transceiver modules and 10G fiber & copper cables.

• 10GBASE SFP+ optical transceivers

SFP+ optical transceivers, according to the IEEE standards, can be divided into several types, for example, 10GBASE-LRM SFP+, 10GBASE-LR, 10GBASE-ER SFP+, 10GBASE-ZR SFP+, 10GBASE-SR SFP+, 10GBASE-T SFP+. Each SFP+ optical transceiver type has its own specification and usage that are not be listed here. For more, please review the previous articles.

• BiDi SFP+ Modules

Besides the above 10GBASE SFP+ modules, 10GBASE-CWDM SFP+, 10GBASE-DWDM SFP+ and SFP+ BiDi optical transceiver modules are also the most commonly used 10G SFP+ optics. SFP+ BiDi optical transceiver usually uses two different wavelength to achieve 10G transmission over one fiber. The most frequently used wavelength of BiDi optical module is 1310nm/1550nm, 1310nm/1490nm, 1510nm/1590nm.

• CWDM/DWDM SFP+ Modules

The Coarse Wavelength-Division Multiplexing (CWDM) and Dense Wavelength-Division Multiplexing (DWDM) SFP+ optics are the convenient and cost-effective solution for the adoption of 10 Gigabit Ethernet in campus, data-center, and metropolitan-area access networks. This 10G fiber optic transceiver type can support up to eight channels of 10GbE over single-mode fibers for distance over 80km.

10G Fiber & Copper Patch Cables

Fiber optic cables can be categorized into two types: single-mode and multimode fiber optic cables. They have different core size and fiber optic transmission equipment, which makes them suitable in different applications. Single-mode fiber patch cables, or OS1/OS2 (OS1 is now not popular on the market) are normally used for long-distance transmission with laser diode based equipment.

Multimode fiber cables, or OM1/OM2/OM3/OM4, have a relatively large light carrying core, usually utilized for short-distance transmission with LED based equipment. OM1, with a core size of 62.5um, supports 1GB network within 300m. OM2 (50um) can support up to 10GB, with a distance of 600m. OM3 and OM4 are the laser-optimized multimode fibers, which can be used in 10GB network with a link length of 300m, 550m respectively. These types of optical cables can be also used on 40G/100G network utilizing a MTP/MPO connector.

Cat6/Cat6a cables are the Copper Ethernet Network cables used for 10G network. Compared with Cat5e (1 Gigabits of data) and Cat5 cables (10/100 Mbps), Cat6 is the Ethernet cable that can handle up to 10Gbps with the distance limited to 164ft. Cat6a is the advanced version of Cat6 cables that further reduce crosstalk, which makes it can support the full 328 feet of Ethernet cable.

Choosing Fiber Optic Cables for 10G SFP+ Optical Transceivers

As noted before, single-mode patch cables can be used for 10G 10GBASE-LRM SFP+, 10GBASE-LR SFP+, 10GBASE-ER SFP+, 10GBASE-ZR SFP+, 10GBASE-CWDM SFP+, 10GBASE-DWDM SFP+ and SFP+ BiDi modules.

	Cable Type	Connector	Max Distance
10GBASE-LRM SFP+	9/125 SMF	LC Duplex	200m
10GBASE-LR SFP+	9/125 SMF	LC Duplex	10km
10GBASE-ER SFP+	9/125 SMF	LC Duplex	40km
10GBASE-ZR SFP+	9/125 SMF	LC Duplex	80km
CWDM SFP+	9/125 SMF	LC Duplex	80km
DWDM SFP+	9/125 SMF	LC Duplex	80km
SFP+ BiDi	9/125 SMF	LC/SC Simplex	80km

Multimode fibers, especially the OM3 and OM4 cables, are supported for 10GBASE-SR SFP+ transceiver modules. The following chart displays the part No. of customized OM3 and OM4 cables.

Customized Part ID	Connector	Fiber Mode	Polish Types	Jacket	Stock Length
17235	LC Duplex	50/125 OM4	UPC	PVC	1m-30m (3ft-98ft)
17235	LC Duplex	50/125 OM4	UPC	LSZH	1m-15m (3ft-49ft)
17235	LC Duplex	50/125 OM4	UPC	OFNP	1m-15m (3ft-49ft)
12018	LC Duplex	50/125 OM3	UPC	PVC	1m-30m (3ft-98ft)
12018	LC Duplex	50/125 OM3	UPC	LZSH	1m-30m (3ft-98ft)
12018	LC Duplex	50/125 OM3	UPC	OFNP	1m-15m (3ft-49ft)

Cat6 and Cat6a Patch cables can be only used on the 10GBASE-T SFP+ transceivers.

Keep in mind, the newly available SFP+ copper transceiver modules can only support up to 30m.

Conclusion

This article lists all the existing the 10G fiber & copper patch cables and SFP+ transceiver module types, as well as the guidance about how to select the right patch cables for 10G SFP+ optical transceivers. FS.COM offers a full range of SFP+ optical transceiver modules and patch cables. Please contact us if you need any help.

Original article: 10GBASE-T SFP+ COPPER RJ45 TRANSCEIVER MODULE – INNOVATIVE BUT CONTROVERSIAL

How to Choose Fiber Optics for Mellanox ConnectX Ethernet Adapter Cards?

Mellanox ConnectX Ethernet adapter card provides high-performance networking technologies by utilizing IBTA RoCE technology, delivering efficient RDMA services and scaling in ConnectX-3, 4, 5, 6 EN 10/25/40/50/56/100/200GbE connection. The Mellanox ConnectX EN Ethernet card supports a full suite of software drivers like Microsoft Windows (including Windows 10), Linux distributions, VMware and Citrix XenServer. ConnectX Ethernet adapter card comes in several types for 10/25/40/50/56/100/200GbE network, such as ConnectX-3 EN, ConnectX-3 Pro EN, ConnectX-3 Pro EN 10GBASE-T, ConnectX-4, ConnectX-4 Lx EN, ConnectX-5 EN, ConnectX-6 EN adapter cards. In this article, we present an in-depth network-level performance evaluation of the Mellanox ConnectX Ethernet adapter cards and the supported fiber optic cabling.

Mellanox ConnectX Ethernet Adapter Card

Network Interface Card (NIC), also known as Network Interface Controller, Network Adapter, LAN Adapter or Physical Network Interface. All Mellanox 10/25/40/50/100/200 Gigabit Ethernet adapters deliver high-bandwidth and industry-leading Ethernet connectivity in enterprise data centers, high-performance computing, and embedded environments. From ConnectX-2 to ConnectX-6, Mellanox keep upgrading their Ethernet adapter cards to meet customers requirement.

ConnectX-6 EN—200Gb/s Adapter Card

ConnectX-6 EN 200Gb/s Adapter Card, launched last year, was the world-first 200Gb/s Ethernet network adapter card for Ethernet connectivity, sub-600 ns latency and 200 million messages per second. ConnectX-6 EN, seen in the image, provides two ports of 200Gb/s for Ethernet connectivity. As the first adapter to deliver 200Gb/s throughput, ConnectX-6 is the perfect solution to provide machine learning applications with the levels of performance and scalability that they require.

ConnectX-5 EN—Adapter Supporting 100Gb/s Ethernet

ConnectX-5 just as the image shows, supports two ports of 100Gb/s Ethernet connectivity, sub-700 nanosecond latency, and very high message rate, plus PCIe switch and NVMe over Fabric offloads, providing the highest performance and most flexible solution for the most demanding applications and markets.

Table 1 presents the detailed information about Mellanox ConnectX-5 EN Ethernet Adapter Cards

Ordering Part No.	Description	Speed	Ports	Connectors	Dimensions w/o Bracket
MCX515A-CCAT	100GbE single-port QSFP28, PCIe3.0 x16, tall bracket, ROHS R6	100GbE	1	QSFP28	14.2cm x 6.9cm (Low Profile)
MCX516A-CCAT	100GbE dual-port QSFP28, PCIe3.0 x16, tall bracket, ROHS R6	100GbE	2	QSFP28	14.2cm x 6.9cm (Low Profile)
MCX516A-CDAT	100GbE dual-port QSFP28, PCIe4.0 x16, tall bracket, ROHS R6	100GbE	2	QSFP28	14.2cm x 6.9cm (Low Profile)

ConnectX-4 EN—Adapter Supporting 10G/40G/100Gb/s

ConnectX-4 adapter cards have three different types: ConnectX-4 Lx EN Programmable Adapter Card, ConnectX-4 EN, ConnectX-4 Lx EN. ConnectX-4 Lx EN Programmable Adapter Card is listed in the right image. ConnectX-4 EN network is the single or dual port 100 Gigabit Ethernet adapter cards. ConnectX-4 Lx enables data centers to migrate from 10G to 25G and from 40G to 50G speeds at similar power consumption, cost, and infrastructure needs. If you are into this NIC card, you'd better look through their difference.

ConnectX-3 Pro EN—10/40/56 Gigabit Ethernet Network Interface Cards

ConnectX-3 Gigabit Ethernet interface card is one of the mostly used NIC cards nowadays. This kind of NIC card can support 10/40/56Gb/s Ethernet connectivity with hardware offload engines. The long-term goal at Mellanox ConnectX Gigabit Ethernet adapter card is to allow customers to wire once and switch protocols on the server and switch as required by workloads. Mellanox can presumably charge a premium for such capability, and ConnectX-3 silicon allows Mellanox to create fixed adapters and switches at specific speeds to target specific customer needs and lower price points, too. The image on the right display the ConnectX-3 Pro Programmable Adapter Cards.

For detailed information about ConnectX-3 Pro EN adapter cards, please see the Table 2.

Ordering Part No.	Description	Dimensions w/o Bracket
ConnectX-3 Pro EN Adapter Cards
MCX311A-XCAT	Single 10GbE SFP+	10.2cm x 5.4cm
MCX312A-XCBT	Dual 10GbE SFP+	14.2cm x 6.9cm
MCX313A-BCBT	Single 40/56GbE QSFP	14.2cm x 5.2cm
MCX314A-BCBT	Dual 40/56GbE QSFP	14.2cm x 6.9cm

ConnectX-2—Supporting 10G Ethernet Switches

Mellanox ConnectX-2 EN cards are the older cards for Ethernet only. That means that they will not work in Infiniband networks. In fact, there are still a few examples of OSes without ConnectX-2 support. Prime examples are FreeBSD 9.3 based FreeNAS and NAS4Free versions which did not have built-in support for the cards. The bottom line is that in terms of compatibility, one does need to verify these cards will work.

Many customers do use these in their Windows 10 home workstation for a 10Gb SFP+ back-haul network. Speeds are reliable and excellent. Nowadays, Mellanox does not supply this card, but ebay and Amazon do provide ConnectX-2 cards under $19.

How to Choose the Cables and Optical Modules for ConnectX-3 Ethernet Adapter Cards?

According to Mellanox, ConnectX-3 10G/40G/56G Ethernet adapter cards are interoperable with 10/40 Gb Ethernet switches. Passive copper cables with ESD protection are supported in this NIC card. ConnectX-3 cards can support up to 56Gb/s that can accommodate several fiber cables and optical transceiver types. Take the MCX313A-BCBT as an example, it has single 40GbE QSFP+ port. QSFP+ optical transceivers and DAC cables are feasible in this Ethernet Adapter Card. For the 10G SFP+ to 40G QSFP+ migration, Mellanox QSA (QSFP+ to SFP+) modules are required.

A previous article QSFP+ to SFP+ Adapter (QSA) Module Vs. QSFP+ to SFP+ Breakout Cable provides the detailed information about how to use the QSA module.

DAC Twinax or 10GBASE-T Copper Cable For ConnectX-2 NIC Cards

Mellanox ConnectX EN Gigabit Ethernet Cards can support up to 200Gbps data rate. Each ConnectX adapter card, as mentioned above, supports optical transceivers and modules applied for 10G/25G/40G/100G Ethernet network. ConnectX-2 EN Ethernet card, for example, can be used for 10GbE networks. Except the expensive SFP+ optical transceivers, SFP+ DAC Twinax and 10GBASE-T copper cables are the commonly used  transmission media for 10G data center inter-rack and TOR switching. So how to choose between them?

DAC Twinax Cable

DAC SFP+ Twinax cables integrates SFP+ modules and Twinax cables on the same conduit. It uses the SFP+ optical transceiver modules as connectors (not the real transceiver) on both ends so as to provide a cost-effective and low-power consumption solution for data center interconnection. 10G DAC Twinax cables can be divided into two types: active DAC twinax and passive DAC cables. For distances >5m and <10m, pickup the active version. Otherwise passive direct attach copper cables should be fine.

Fiberstore is one of the best vendors for DAC and other fiber optics. Their packaging and after-sale support for even the smallest orders is excellent. For connecting two ConnectX-2 cards together, you can get one of the SFP+ copper cables.

Ethernet Network Cables

Ethernet Network Cables like Cat5, Cat5e, Cat6 do look alike from the outside and they all use the same connectors as well. However, they have significant differences on the inside. One simple method is that you can find out the type of cable you have by looking at the text printed on the side of the cable. There are other cables possible (like Cat7 and Cat8 cables) but Cat5, Cat5e, Cat6 cables are the most common now.

• CAT5

Category 5 cabling is an older type of network cabling compared with Cat5e and Cat6 cables. Cat5 cables support transfer speeds of 10/100 Mbit/s (Fast Ethernet). Nowadays, many installers treat it as old and obsolete and try not to use it. For those who buy cat5 cables,  they tend to use in older devices such as an older router or switch.

• CAT5e

Category 5 enhanced (Cat5e) cables currently are the most commonly used Ethernet network cables owing to its enhanced transmission data rate and reduced crosstalk. Cat5e cabling supports 1000 Mbit/s and cust down on external and internal crosstalk. It basically means that Cat5e is better at keeping signals on different circuits or channels from interfering with each other.

• CAT6

Category 6 cabling (Cat6) supports 10 Gbit/s speeds with additional crosstalk improvements. If you're purchasing a new cable for future proofing,  it should really be CAT6 or above. That doesn't imply Cat6 cables protect your network from the future or anything, it just means it will keep it up to date for longer when the next products comes along.

Note : Your network speed depends on  the slowest part of your setup. If you want to deploy gigabit ports, gigabit routers, switches,  then please make sure you cabling also supports those speeds as well.

 

Summary

Mellanox is the world-class vendor for selling multi-protocol chips and adapter cards for servers. It provides a wide range of high-speed interconnection solutions including Gigabit Ethernet cards and InfiniBand adapter cards. The above mentioned ConnectX Gigabit Ethernet cards can not be used in InfiniBand networks. ConnectX Mellanox Gigabit Ethernet cards are the cost-effective devices for your network applications. If you do have the Mellanox NIC cards, you can buy the cost-effective DAC and optical transceiver modules from FS.COM to further reduce the total cost of your budget.

Do You Know About Cat 8 Cable?

Cat 5e or cat 6 cables now are the mainstream of the copper network solution, but optical technology are progressing to promote higher category copper cables for the increasingly heavy-loaded data center solution. Cat 8 cables lately has been much talked about, especially after the TIA category 8 cabling standard approved. Category 8 is regarded as the next-generation twisted-pair cabling specification for higher data rate, but it is still under development. Here is what we need to know about the basics of Cat 8 cabling.

Main Features of Category 8 Standard

Cat 8 cable is especially designed to support 25G or 40G Ethernet data rate with a link distance of up to 30 meters, which is sufficient for most switch-to-server connections for top-of-rack (ToR), middle-of-row (MoR) or end-of-row (EoR) topologies. In addition, category 8 cabling is fully backward compatible with category 6A cabling, including RJ45 connectivity, and supports all Category 6A applications such as 10GBASE-T for a distance of 100 meters.

Category 8 cabling and components are specified with transmission performance of up to 2 GHz (four times the bandwidth of Category 6 cabling and two times the bandwidth of category 7) with more stringent alien crosstalk requirements. Meeting these requirements requires a shielded cabling system (F/UTP, S/FTP or F/FTP), just as seen in the above picture. What’s more, the cat 8 cables do not need more power to operate over shorter distances for 25GBASE-T/40GBASE-T application. The power needed to transmit a signal 30 meters at 40 Gb/s is approximately the same as the power needed for 10GBASE-T transmission for distances up to 100 meters.

How to Compare Category 8 to Those of Previous-Generation Twisted-pair Cabling Systems—Category 5, 6, 6A, 7, 7A?
The cat 5e cables was introduced in 1999 with the use of 100-meter, 4-connector channel in structure cabling. The primary differences between category systems is the frequency at which the signal is transmitted over the cable. Cat 6 cables are designed to support 10Gbqs with a frequency of 500 MHz. While Category 7/7A as n advanced version of cat 6 cables offers a 100-meter 4-connector channel using shielded cabling, and has been designed to transmit signals at a frequency of 1000 MHz. Even though Category 7/7A operates at the higher frequency, there is no corresponding improvement in data rate over Category 6A because 10GBase-T is still the fastest twisted-pair-based data rate recognized by IEEE 802.3.

Category 8 is a significant departure from previous systems in that it uses a frequency of 2000 MHz, and is limited to a 30-meter 2-connector channel. Unlike Category 5e or Category 6A, which could use either unshielded twisted-pair (UTP) or shielded cable construction, Category 8 will require shielded cabling. The most likely cable construction for Category 8 will be 22-AWG S/FTP cabling. Category 8 is also unique in that the ISO standard will recognize two different classes of product. Class I is based on the traditional RJ45 connector, while Class II will accept non-RJ45 connectors similar to Category 7/7A. While both solutions will offer backward compatibility in terms of transmitting the lower category data rates (1G or 10G), the Class I solution offers a migration path using the RJ45 connector platform. For example, a customer might install a Category 8 jack-to-jack link now, but continue to use Category 6A patch cords until the active equipment is upgraded.

Given Category 8’s Capabilities, Where Is It Most Likely to be Deployed?

Category 8 cabling is designed to support emerging IEEE 25GBase-T and 40GBase-T needed as server-to-access-switch interconnect applications. This need has been identified and available, or under development, over optical fiber links for longer reach (up to 500 meters), or twinax links for short reach (up to 7 meters).

The opportunity for balanced twisted-pair as a cost-effective viable media option for the intermediate distance needs between 5 and 30 meters, sufficient to serve 20 cabinets or racks in a data center, led to the initiation and development of both the IEEE 802.3 application standards and the associated TIA as well as ISO/IEC Category 8 cabling standards.

How to Install Category 8 Cables?

Category 8 will be a shielded, field-terminable, and with a very high bandwidth. Thus there to be at least some improvements made to how jacks are terminated in the field to both meet this new bandwidth and to ensure a good bond with the shield. Additionally, contractors must make sure that the cable is properly grounded. If the connector companies do their job right, grounding the Category 8 cables and connectors will be a seamless process for the installer, which is all based on the RJ45 connector. Any component qualified as a Category 8 component will also meet requirements specified for Category 6A and lower components.

Conclusion

Cat 8 product recently is not available on the market now, but it is believed that in the near future cat 8 related items will be ubiquitous. Cat 8 cabling are meant to support 25GBASE-T and 40GBASE-T specifications, which will greatly propel the development of 25G and 40G network. FS.COM will continue our efforts to stay in close touch with the latest technology and bring you the best products and services. We provide plenty of Cat 5/cat 6/ cat 7 components to meet your special requirement. Besides the copper cables, we also have the fiber optic cables terminated with several connectors like SC fiber patch cord, fiber patch cables LC to LC, LC to LC patch cord and so on. If you want to know more about our products, please sens your request to us.

Using HDMI Cables for High-Quality Transmission

As audio video systems and installations have become more complex over time, it is common for people to use HD TVs, HD media players, and other home theater systems. Additionally there seemed to be a big variance in quality between brands, especially when it came to extending HDMI signals. Therefore, the introduction of HDMI technology is a game changer and highly appreciated by overall users in this days. Just as fiber jumper connecting optical equipment, HDMI cables offer long-distance HD audio and video signals transmission playing an important role in achieving brilliant performance. Today’s article will have a brief introduction to this cable.

HDMI Cable

HDMI ((High-Definition Multimedia Interface) cable is composed of four shielded twisted pairs with several separate conductors for transferring data over video/audio devices. A HDMI cables are defined into two cable categories: one is the Category 1-certified cables, known as standard HDMI cables, the other is Category 2-certified cables, also called high speed HDMI cables. HDMI cables has not been specified the transmission length. A cable of about 5 meters (16 feet) can be manufactured to Category 1 specifications easily and inexpensively by using 28 AWG conductors. With better quality construction and materials, including 24 AWG conductors, an HDMI cable can reach lengths of up to 15 meters (49 feet). HDMI cables are expensive than the regular Cat6/Cat7 cables. Just as anything else, whether you want to use the expensive but high-performance HDMI cables or cheap but low-performance Category copper cables like Cat5e/Cat6, it depends on what inputs you tech has. The below part lists the current usage of HDMI cables, and you can look at the solutions that interest you. The following image shows the image of a HDMI cables connecting box and HDMI socket of TV.

Difference Between an HDMI Cable and a DVI Cable

HDMI cable and DVI cable as two two input-output media interfaces in home network are posing difficulty in distinguishing them. In fact, the biggest difference between these two transmission media lies in their layout. An HDMI cable is more compact and resembles a USB cable, while a DVI cable is usually bigger in size. Another major difference is in capability: the HDMI supports audio and video, whereas the DVI is strictly video-only.

Applications of HDMI Cables

• Boosted HDMI: HDMI cables, with a booster integrated into their structure use the 5v power rail of the HDMI signal to carry the data further without loss of fidelity. This cable, compared with the normal HDMI cable, is intended to make longer cable runs, but it can also be used to make a short cable thinner and much more flexible. HDMI cables with integrated booster chipsets are more expensive than their basic counterparts, and so far only cater to 1080p content due to the loss of bandwidth over the extended length, but they can reach 40 meters.
• HDMI over CAT: It is not a new concept to use Cat5 or Cat6 cables to extend an AV source. HDMI recently make use of this technology for stable extended runs—sometimes even using existing network cabling. Due to bandwidth limitations, most CAT extenders only support 1080p, but some can handle 3D, too. Configuration is more complex than regular cables, and interference can be a big problem in some environments, but with a good HDMI over Cat5/6 Extender, you can run 50 meters.

• HDMI over Fiber Optics: Fiber optics for HDMI, compared with HDMI over CAT, carries the highest price premium, but they have the much better capacity to outstrip copper based cables for distance by a large margin. The added benefit to this cable type is flexibility with a maximum distance of 45 meters. The optical core is much smaller than Boosted HDMI, but can go the same distances. Note that some companies have kits which run much longer, but it of course will cost far more!
• HDMI over Wireless: Wireless technologies vary between models, but one thing they have in common is they don't generally go as far as cables do. Line of sight is 10 to 15 meters, and through walls can be as low as 5 to 8 meters. Unless you can't run a cable at all, a lead will beat Wireless every time. Wireless is also limited by bandwidth to 1080p, and only the best units can handle 3D.

Some Terms Appeared in the Above Part

1080p refers to an HDTV format which has 1080 horizontal lines of resolution. The p stands for progressive scan. The traditional analog video uses an interlaced scan, which draws the odd lines, then even lines of each frame in sequence.

AWG is short for American Wire Gauge, which is a common unit of wire measurement. AWG expressed in a HDMI cable refers to the size of the conductors within the cable. With wire gauges, smaller numbers actually refer to larger wires. This means a 24 AWG cable has a thicker conductor than a 28 AWG cable. The benefit of a thicker conductor is the ability to effectively transmit an HD signal.

Plenum refers to the air-handling spaces in building construction above the ceiling and beneath the floors. Some building codes require Plenum-rated cable, which has a low-smoke jacket that burns slower in the event of a fire and emits less toxic smoke.

Summary

This article isn’t a definitive guide to HDMI cables, but for the sake of simplicity we just provide some basic information about industrial and commercial applications of HDMI cables. If you are on the fence to install a fiber optic network, always use the shortest length of cable you can live with, and ensure they're certified by the industry bodies. What’s more, it is advisable for you to save your money for other home network components and get your HDMI cables as cheaply as possible. FS.COM offers a full range of optical products including fiber optic cables (e.g. SC to LC patch cable), copper cables (like Cat5e, Cat6), optical transceivers and so on. If you want to know more information about our products, please send your request to us.

Color Code Standard of Ethernet Cable – T-568B and T-568A

Ethernet cables are the standard cables used for almost all purposes that are often called patch cables or fiber jumper. In an article “How to Choose Ethernet Cable”, we know that Ethernet cables can be categorized into many types, like straight-through and crossover Ethernet cable, UTP or STP, Cat5 or Cat6, etc. But we know little about the pins and wiring in Ethernet cables and RJ45 plugs.

RJ-45 conductor cable contains 4 pairs of wires, each consisting of a solid colored wire and a strip of the same color. There are typically two wiring standards for RJ-45 wiring: T-568A and T-568B. What do they mean, and why they are important? This post will discuss the color diagram of straight-through and crossover Ethernet cable to help you figure out.

Straight-Through and Crossover Cables

Straight-through refers to the Ethernet cables that have the pin assignments on each end of the cable—Pin 1 connector A goes to Pin 1 on connector B, Pin 2 to Pin 2 etc. Straight-through wired cables see in Figure 1 are most commonly used to connect a host to client. For example, the straight-through wired cat5e patch cable is used to connect computers, printers and other network client devices to the router switch or hub (the host device in this instance).

While an crossover cables are similar with straight-through cables, except that TX and RX lines are at opposite positions on either end of the cable, in other words, Pin 1 on connector A goes to Pin 3 on connector B. Pin 2 on connector A goes to Pin 6 on connector B ect. Crossover cables are most commonly used to connect two hosts directly.

What’s more, the color code diagram of these two cables are different. To create a straight-through cable, you will use either T-568B or T-568A on both ends, while to create a cross-over cable, you will wire T-568A on one end, and T-568B on the other end.

T-568B and T-568A Standard

T-568A and T-568B are the two wiring standards for RJ-45 connector data cable specified by TIA/EIA-568A wiring standards document. T-568A standard ratified in 1995, was recently replaced by the T-568B standard in 2002. The difference between the two is the position of the orange and green wire pairs. It is preferable to wire to T-568B standards if there is no pre-existing pattern used within a building.

Both the T-568A and T-568B standard Straight-through cables are used most often as patch cords for your Ethernet connections. If you require a cable to connect two Ethernet devices directly together without a hub or when you connect two hubs together, you will need to use a Crossover cable instead.

Looking at a T-568A UTP Ethernet straight-through cable and an Ethernet crossover cable in the above image with a T-568B end, we see that the TX pins are connected to the corresponding RX pins, plus to plus and minus to minus. You can also see that both the blue and brown wire pairs on pins 4, 5, 7, and 8 are not used in either standard. What you may not realize is that, these same pins 4, 5, 7, and 8 are not used or required in 100BASE-TX as well. So why bother using these wires, well for one thing its simply easier to make a connection with all the wires grouped together. Otherwise you’ll be spending time trying to fit those tiny little wires into each of the corresponding holes in the RJ-45 connector.

Conclusion

Ethernet cable color-coded wiring standard allows optical technicians to reliably predict how Ethernet cable is terminated on both ends so they can follow other technicians' work without having to guess or spend time deciphering the function and connections of each wire pair. There is no technical difference between the T568A and T568B wire standard, so neither is superior than the others. FS.COM offers a full range of optical devices including fiber optic cables like LC-SC fiber cable, copper cables (Cat5/5e, Cat6), etc. If you have any requirement of our products, please send your request to us.

How To Choose Ethernet Cable

Ethernet cable is used to connect devices on local area networks (switch, router or hub), which is one of the most popular forms of fiber jumper cables used on wired networks. Ethernet cables are typically classified into sequentially numbered categories based on different specifications, such as cat5, cat5e, cat6, etc. What are the differences between these category Ethernet cable and how can you know when to use unshielded, shielded, stranded, or solid cable? This article will help you find the suitable one.

Category Ethernet Cable Difference

The Cat3, Cat4, Cat5, Cat5e, Cat6, and Cat7 are the abbreviation for the category number that defines the performance of UTP (Unshielded Twisted Pair) type of cable used for Ethernet wiring outlined by the Electronic Industries Association (EIA) standards. The differences in these cable specifications is not easy to identify. However, as the category number gets higher, so does the speed and Mhz of the wire. The following image shows a comparison between Cat5, Cat6 and Cat6 UTP cables.

Besides the speed and hertz, there are two main physical differences between Cat5 and Cat6 cables, the number of twists per cm in the wire, and sheath thickness. It is known that cable twisting length is not standardized, but typically there are 1.5-2 twists per cm in Cat5e and 2+ twists per cm in Cat6. The amount of twists per pair is usually unique for each cable manufacturer. From the above picture, you can see that no two pairs have the same amount of twists per inch. And Cat5e cable has the thinnest sheath, but it also was the only one with the nylon spline. The nylon spline can help eliminate crosstalk, the thicker sheath protects against near end crosstalk (NEXT) and alien crosstalk (AXT) which both occur more often as the frequency (Mhz) increases.

Nowadays Category 5 cable was mostly replaced with Category 5 Enhanced (Cat5e) cable which did not change anything physically in the cable, but instead applied more stringent testing standards for crosstalk. While Category 6 was revised with Augmented Category 6 (Cat6a) which provided testing for 500 Mhz communication (compared to Cat6’s 250 Mhz). The higher communication frequency eliminated alien crosstalk (AXT) which allows for longer range at 10 Gb/s.

Shielded (STP) vs. Unshielded (UTP)

All Ethernet cables are twisted pair, but they are created equally. Telecom vendors rely on shielding to further protect the Ethernet cable from interference, thus the shielded twisted cable (STP) is more suitable for area with high interference and running cables outdoors or inside walls. Unshielded twisted pair however, can easily be used for cables between your computer and the wall. Technically the picture below shows a UTP and STP cables.

There are different methods to shield an Ethernet cable, but typically it involves putting a shield around each pair of wire in the cable. This protects the pairs from crosstalk internally. Manufactures can further protect cables from alien crosstalk but screening UTP or STP cables.

Solid vs. Stranded

Solid or stranded refer to the actual copper conductor in the pairs. Of an Ethernet cable. Solid conductor uses 1 solid wire per conductor, so in a 4 pair (8 conductor) roll, there would be a total of 8 solid wires. Stranded conductor uses multiple wires wrapped around each other in each conductor, so in a 4 pair (8 conductor) 7 strand roll, there would be a total of 56 wires.

Each type of conductor (see in the above picture) can be utilized in different applications. Stranded cable is more flexible and should be used at your desk or anywhere you may be moving the cable around often. Solid cable is not as flexible as stranded cable, but more durable which makes it ideal for permanent installations as well as outdoor and in walls. Stranded wire are generally made with patch leads with connectors on the either end like LC to SC patch cord.

Conclusion

Due to the electrical transmission characteristics, a single Ethernet cable like an electric power cord, can extend only limited distances. At the end of the article, you may know when to choose STP, UTP, stranded or solid cables. Note that if you're cabling a mission critical system or you want your network to be future proof, go for the CAT6 cables, but for the average home or small office network CAT5 or CAT5e will be just fine.

The Reality of Copper and Fiber Cable

The war between copper and fiber has been raged for years and it is never ended. Copper-based systems maintain the same upgrade path that they have for years, while fiber-optic proponents continue to advocate their sense of superiority, which forces people to face the dilemma of selecting copper or optical fiber. So, once again, which cabling type is the best overall value for their current and projected future needs? This article carefully looks into the question and gives you the reality of the present copper and fiber cables.

Major Difference Between Copper and Optical Fiber

Cable length and data rates are two of the key criteria that differentiate the use of copper or fiber optic cable. If you require a long link length and high data rate, then fiber cable may be the obvious choice, and you can move on to selecting a specific fiber cable. Alternatively, if the runs are short and the data volume fits within copper's capacity, then copper it is. Some other general differences between copper and fiber optic cables are offered in the table. Once you understand the distinct properties of copper and fiber, your solution may seem clearer. Now let’s come to the reality of both cables to help you select the suitable one.

Copper Cabling in Gigabit Ethernet Application

Category 6 or Cat6 data cabling as one of the most popular copper cables in the market today, has been utilized for Gigabit Ethernet and several other network protocols. As the sixth generation Ethernet cables formed from twisted pairs of copper wiring, cat6 is composed of four pairs of wires, similar to cat5 cables. The primary difference between the two, though, is that cat6 makes full use of all four pairs. This is why cat6 can support communications at more than twice the speed of cat5e, allowing for Gigabit Ethernet speeds of up to 1 gigabit per second.

However, there are some link restrictions in using this type of data cabling. When used for 10/100/1000BASE-T, the restriction of the copper cable is 100 meters, and when used for 10GBASE-T, the restriction is 55 meters. Another issue is that there are some cat6 cables that are very large and are quite difficult to connect to 8P8C connectors (a type of modular connector used for communications purposes such as phone/Ethernet jacks) when the user does not have a unique modular piece.

Copper cable still has a place in the telecom field, the best prove is that copper cable has improved itself to face the ever-increasing bandwidth requirement. For 40G Ethernet, there are 40G DAC cables — passive copper cable or active copper cable available in the market to achieve 40G connectivity. For example, Cisco QSFP to QSFP+ copper cables, like QSFP-H40G-CU1M and QSFP-H40G-ACU7M are widely used to connect within racks and across adjacent racks.

Fiber Optic Cabling

Fiber optic cable is completely unique from cat6 and other types of copper cabling systems. The most obvious feature about optical fiber is that it draws on light instead of electricity to transmit signals. In addition, optical fiber is immune to electrical interference, which means that a user can run it just about anywhere, anytime. However, fiber is not that easy to install. Terminating fiber optic cable is not as simple as copper. While manufacturers have developed crimp-on connectors, they are expensive, high loss and have not been very reliable. Fiber optic connectors need adhesives for reliability and low cost. And most installation involves stripping fibers, injecting adhesives and polishing the ends. No IDC (insulation displacement connectors) here. Any good installer can learn how to terminate fiber in less than 2 hours. The following picture shows a singlemode and multiomde optic cable.

Not all fibers have infinite bandwidth. At least not the multimode fiber used in most premises networks. It's a lot higher than copper, but as you approach gigabit speeds, you are limiting the distances available for links to 500 meters or so. Singlemode fiber, as used in telecom and CATV networks, practically has infinite bandwidth. But it uses higher cost components and can be pricey for shorter links. It's not necessary for today's networks but may be for the next generation. Well, fiber prices continue to fall while copper prices rise.

Know Your Application, Then Select Your Cable

Just as knowing it’s vital to select the right switches, routers and firewalls for an industrial Ethernet network, it is also vital to select the right cable. When it comes to industrial Ethernet cable, long reach and high data volumes call for fiber cable. For short runs and average data requirements, copper cable will do the job. Next consider the operating environment and mechanical devices will face to help you on a final choice. Fiberstore provides various copper cables and fiber cables, including OM3 cable, OM4 cable, Cat6A copper cable, Cat5A copper cable and other specific cables. 40G DACs and AOCs are also offered. You won;t miss it.