Maximum Distance For Data Transmission Over Network Cable
The network more understanding of the guys, we all know that twisted pair cable has an “insurmountable””100 meters” transmission distance. Whether it is 10M transmission rate of CAT3 of twisted-pair cable, or 100M transmission rate of CAT5 of twisted-pair cable, and even 1000M transmission rate of CAT6 of twisted-pair cable, the farthest effective transmission distance of 100 meters.
In the integrated wiring specification, also clearly required horizontal cabling can not exceed 90 meters, the total length of the link can not exceed 100 meters. That is to say, 100 meters for wired Ethernet is a limit, this limit is from the network card to the hub device link length.
How Do You Get The 100 Meter Maximum Distance?
What causes the 100 meter transmission distance limit for twisted pair?
This is to look deeper into the deep physical principles of twisted-pair cable. Network transmission, in fact, is the network signal transmission over twisted-pair cable, as an electronic signal, transmission in twisted-pair cable, it is bound to be affected by resistance and capacitance, which leads to the network signal attenuation and distortion. The attenuation or distortion of the signal reaches a certain level, which will affect the effective and stable transmission of the signal.
How Exactly Is The 100 Meter Llimit Calculated?
Category 5 UTP, Ultra Category 5 UTP is mainly for computer network services, according to the Fast Ethernet 100Base-TX regulations, its communication rate is 100mbps, 100mbps Ethernet transmission of 1 bit of data time spent (also known as “”bit time””) can be calculated as follows:
1 bit time = 1/100mbps = 10ns
Data and information traveling through a network is delayed as it passes through the different components, with Category 5 UTP having a delay of 5.56ns/m.
When designing an Ethernet network, there is a trunking rule that is required to be followed, also known as the Golden Rule or the 5-4-3-2-1 rule, which applies not only to 10mbps Ethernet but also to Fast Ethernet.
This rule requires that the ring conflict delay must not exceed 512 bit-hours, which is 5120ns for a 100mbps transmission rate. In the ring, the network components are cables, relay units, MAUs and DTEs, etc., add up their delays and multiply by 2 to obtain the ring delay, and the ring conflict diameter can also be calculated. Based on this theory, the furthest distance a signal can be transmitted to ensure that a minimum frame is sent before it is completed can be calculated. This is the reason why the link span is limited to 100 meters.
When it exceeds 100 meters, the conflict cannot be detected in time, the information packet which is damaged due to the conflict is transmitted, and it is received by the receiver, and this information packet is forced to be discarded because it cannot be verified, and at this time, the mechanism of backward re-transmission is not activated, so it will result in the loss of the packet.
When the transmission rate is lower than 100 mbps, the limit of 100 meters can be appropriately relaxed in practical applications. It must be stated that this actually, although effective, does not comply with the standard. It must be stated in the certification test, otherwise there will be the possibility of problems, such as product warranty.
Maximum Cable Distance During Actual Construction
As can be seen from the above, when using PoE power supply, why it is specified that the maximum length of the network cable should not exceed 100 meters. However, in actual construction, in order to ensure the quality of the project, generally take 80-90 meters.
Please note that the transmission distance here refers to the case of the maximum rate, such as 100M, if the rate is reduced to 10M, the transmission distance can usually be extended to 150-200 meters (depending on the quality of the network cable). So PoE powered transmission distance is not determined by PoE technology, but by the ethernet cable and quality of the network cable.
Although in actual construction, better quality network cable can break through the limit of 100 meters distance, and the equipment can work properly, but this practice is not recommended. This is because there are potential problems that do not present themselves immediately, but appear slowly over time, which can cause subsequent maintenance problems. The simplest case, such as bandwidth upgrades, so that the original can work at a distance of more than 100 meters in the original equipment will not work properly after a significant increase in network speed.
Impact Of Cable Type And Quality On Transmission Distance
Category 5 cable (Cat 5)
Is now the most common standard network cable on the market, but the quality of different manufacturers vary greatly, especially in the price-oriented environment, many manufacturers in order to reduce the cost of copper wire with copper-clad iron, copper-clad steel instead, resulting in a decline in the transmission distance of the network cable, and even the occurrence of network instability, packet loss and other phenomena, and equipment manufacturers are often therefore backed by the black pot, and also really wrong.
So if you want to make PoE play the best effect, you must use good quality ethernet cable, can not be a small loss, affecting the overall quality of the project.
Ultra Category 5 cable (Cat 5e)
Compared with Category 5 twisted-pair cable, Ultra Category 5 twisted-pair cable has less attenuation and crosstalk, providing a more solid network foundation for most applications (especially supporting Gigabit Ethernet 1000Base-T cabling), bringing convenience to network installation and testing, and making it a better solution for current network applications.
The transmission characteristics of Ultra Category 5 cable are the same as those of normal Category 5 cable, but the Ultra Category 5 cabling standard specifies that all 4 pairs of Ultra Category 5 cable are capable of full duplex communication.
Category 6 cable (Cat 6)
This category of cable transmits from 1MHz to 250MHz. Category 6 cabling systems should have a large margin of combined attenuation crosstalk ratio (PS-ACR) at 200MHz, which provides two times the bandwidth of Ultra Category 5. The transmission performance of Category 6 cabling is much higher than that of the Ultra Category 5 standard and is best suited for applications with transmission rates higher than 1Gbps.
An important difference between Category 6 and Category 5 is the improved performance in terms of crosstalk as well as return loss, which is extremely important for the new generation of full-duplex, high-speed network applications. Category 6 standard eliminates the basic link model, cabling standards using a star topology, the required cabling distance: the length of the permanent link can not exceed 90 meters, the length of the channel can not exceed 100 meters.
Category 6 cable and Category 5e cable in the transmission distance is not strictly different, that is, the maximum transmission distance of a single segment are 100 meters. Of course, Category 6 cable in the transmission distance can be increased appropriately, the so-called 100 meters refers to more than can not meet the 1000M bandwidth and other related technical indicators, bringing speed degradation and other issues.
What Is The Difference In Transmission Distance Between A Four Core Network Cable And An Eight Core Network Cable?
Network cable is one of the media as a network transmission signal, the current commonly used network cable are 8 core network cable, part of the ordinary project will use 4 core network cable, in the 100 megabit network, the network cable is to rely on one of the internal 4 main lines to transmit the network, in a sense, 8-core cable and 4-core cable in the transmission of the network process is not very different.
In a sense, there is no difference between the 8 core cable and the 4 core cable in the process of network transmission. However, the 4 core cable is obviously not as good as the 8-core cable in terms of transmission effect and stability.
4 core Network Cable
It refers to the network cable with only 4 cores inside, and the general colors of the cores are orange-white, orange, green-white and green. The specifications of 4-core network cable are not many, generally divided into indoor copper-clad aluminum/oxygen-free copper 05 network cable and outdoor copper-clad aluminum/oxygen-free copper 05 network cable. The production process of 4-core network cable is relatively simple, which can ensure the normal network transmission and reduce the cost in the ordinary network environment.
4 core network cable can be used as network cable, telephone line, generally used to do broadband rental main line, due to rental housing network needs are temporary, one-time more, for the network requirements are not very high and the cost is lower than the use of 8-core network cable.
If you make your own four-core network cable connector, you can use the network cable clamp to press the crystal head, the network crystal head usually use the Cat5e crystal head, according to the T568B core, you can access the four cores to the crystal head 1.2.3.6 position. (Crystal head up from left to right: 1.orange white, 2.orange, 3 green white, 6 green)
8 Core Network Cable
It refers to the network cable that has eight cores inside, and the colors of the cores are orange-white, orange, green-white, green, blue, blue-white, brown, and brown-white. Eight-core network cable specifications are more, divided into Cat5e cable and Cat6e cable.
Cat5e network cable is divided into indoor network cable and outdoor network cable (conductor material: iron aluminum, copper-clad aluminum, high conductivity aluminum, copper-clad silver, all copper, oxygen-free copper, conductor size: 0.45-0.51mm).
Cat6 network cable is also divided into indoor network cable and outdoor network cable (conductor material: copper-clad silver, all copper, oxygen-free copper, conductor size: 0.52-0.58mm).
Under the 100 megabit network, 8-core network cable can rely on 4 cores to transmit, in the POE power supply and under the gigabit network must be utilized to 8 cores to transmit the network.
Connect the crystal head in accordance with the T568B core, you can access the 8 cores to the crystal head, crystal head up from left to right: 1. Orange White, 2. Orange, 3 Green White, 4. Blue 5 Blue White.6 Green 7. Brown White 8 Brown.
The 4 core network cable will sometimes have unstable transmission and is not suitable for large networks.
Network cable transmission distance and wiring environment also has a certain relationship, 8 core cable in the 4.5.7.8 this line plays a role in reducing interference, so that the transmission signal will not have too much loss, and 4 core cable in this regard is not as good as 8 core cable performance. 4 core cable in actual use, it is best to keep in the transmission distance of about 85 meters.
In Summary
Copper network cable, whether in the daily integrated wiring or in the data center plays an important role in high-speed transmission and link. Due to the characteristics of copper metal, the link design should consider the length of the link distance, the transmission power of the link device and the expansion and upgrading of the network, so as to avoid the big attenuation due to the long transmission distance of the cable or the expansion of the ONU and other equipment can not work.
Bonelinks cares about and understands the link design of our customers, and has always been committed to providing the link design to meet the network cable and fiber optic patch cords and other passive components to help users achieve affordable Internet access. Bonelinks has always been committed to providing passive components such as network cables and fiber optic patch cords that meet the link design to help users realize affordable Internet access. Please contact us for more details.