What are the common problems of six types of wiring

As we all know, Category 6 network cables have very strict performance standards, and the requirements for installation quality are even higher. Any installation errors or shortcuts in Category 6 cabling may result in barely passing or failing tests. So, what should be paid attention to in the installation of Category 6 wiring? What are the common problems of Category 6 wiring?

What should be paid attention to in the installation of six types of wiring

(a) Cable tension

Do not exceed the cable pull tension specified by the cable manufacturer. Excessive tension will deform the twist pitch in the cable, seriously affect the ability of the cable to suppress noise (NEXT, FEXT and derivatives), and seriously affect the structural return loss of the cable, which will change the impedance of the cable and damage the overall return. wave loss performance. These factors are important factors in the transmission of high-speed local area network systems, such as Gigabit Ethernet. Also, this can cause the pairs to unravel, potentially damaging the wires.

(b) Cable bending radius

Avoid excessive bending of the cable as this will change the lay length of the pairs in the cable. If bent excessively, the wire pairs may spread apart, resulting in impedance mismatch and unacceptable return loss performance.

In addition, this may change the relationship between the 4-pair lay lengths inside the cable, causing noise suppression issues. Various cable manufacturers recommend that the cable bend radius be no less than 8 times the installed cable diameter.

For a typical Category 6 cable, the bend radius should be greater than 50mm. One of the most critical areas of the problem is the wiring closet, because the large number of cables entering the patch panel can cause some cables to be over-stressed and over-bent in order to keep the wiring clean. Often invisible, even the most dedicated installer can inadvertently degrade the performance of a cabling system.

If the manufacturer provides rear cable management devices, be sure to use these devices in accordance with the manufacturer's recommendations. However, the cable bend radius inside the device has different (more stringent) restrictions.

In general, the cable bend radius during installation is 8 times the cable diameter. In practice, the bend radius in the back box is 50mm, and the minimum bend radius for incoming cable ducts is 100mm. For buildings where smaller diameter cables were originally installed/specified, this has a significant impact on reusing legacy device systems inside the building.

(c) Cable compression

Avoid over-tightening the cable ties and compress the cables. This problem is most likely to occur in large bundles of cables or cable installations, where the cables on the outside of the bundle will experience more stress than the cables on the inside. If the cable is too tight, the stranded wires inside the cable will be deformed, affecting its performance, and generally making the return loss more obviously unqualified.

The effects of return loss accumulate, and each overtight cable tie pair increases the total loss. Worst-case conceivable is the use of cable ties every 300mm in long run cables hanging from dangling wires.

If the cable hanging on the hanging wire is 40 meters long, the number of cable ties is 134 times. When using cable ties, pay special attention to the amount of pressure applied to the tie. The cable ties are strong enough to support bundles of cables.

A better approach is to ensure that there is no deformation of the cable jacket when tying the cables together using cable tie pairs. This is also very important in wiring closets where the user typically tightens the cable ties to keep the cables clean, or where it is difficult to access the termination points on the back of the panel.

We recommend using hooks and looped cable ties, such as Velcro brand ties. These devices make it impossible to damage cables due to compression, and they are also easier to remove. This makes it easy to add more cables to the bundle, but at the same time they make it easier for unauthorized persons to modify the wiring.

(d) Cable weight

Note that Molex Enterprise Cabling Network Division 23 gauge (or 0.6mm diameter) Category 6 cable weighs approximately twice as much as Category 5 cable. A meter of 24 Category 6 cables weighs close to 1.0kg, while the same amount of Category 5 or Category 5e cables weighs just 0.6kg. The weight of the cable must be considered when using the suspension wire to support the cable. It is recommended that each suspension wire support point support a maximum of 24 cables per bundle.

(e) Cable knots

When pulling the cable from the spool, be aware that the cable can sometimes get tangled. If the cable is kinked, it should be considered damaged and the cable should be replaced. Installation pressure can cause installers to straighten cable knots.

However, the damage has occurred and this will be discovered when the cable is tested. Remember that all of these effects add up, and while it is unlikely that a single cable knot will fail the test, this effect combined with the performance degradation caused by cable ties and the reduced margin for Category 6 cabling will cause the test to fail.

(f) Number of cables in a bundle of cables

When any number of cables are bundled together in very long parallel lengths, the pair capacitive coupling (eg blue pair to blue pair) of different cables in a bundle of cables with the same lay length can result in a significant increase in crosstalk.

This is called "alien crosstalk", and this metric has yet to be specified or precisely defined by a cabling standard. The best way to eliminate the adverse effects of alien crosstalk is to minimize the length of long parallel cables and install bundles of cables in a pseudo-random fashion.

Historically, we have used "comb" routing in our traces to keep things clean. Bundling the cables together is the best way to avoid any two pairs of different cables that might run in parallel for the effective length. There are no shortcuts or other efficient ways to do this but it should be noted that long parallel lengths of cable may lead to potential alien crosstalk.

(g) Cable jacket stripped

At the cable termination point, the exposed wire pairs from the sheath to the IDC after termination must be kept to a minimum. It is not absolutely necessary to strip the cable jacket, it is just that the conductors can be comfortably attached to the IDC. TIA or ISO wiring standards specify the stripped jacket length.

By minimizing the length of the jacket to be stripped, this ensures that the pair lay distance inside the cable can be maintained for the most efficient transmission path. Excessive jacket stripping on the IDC will compromise the NEXT and FEXT performance of the Category 6 cabling system.

(h) Pairs spread out

At the cable termination point, the lay length of each pair in the cable should be as close as possible to the IDC. The pair lay length is calculated by the cable manufacturer, and changing the cable lay length will adversely affect the cable performance. Although the ISO and TIA Category 5e cabling standards specify the length (13 mm) at which pairs are spread out, they do not make such provisions for Category 6 cabling.

The current recommendation is to follow the recommendations provided by the manufacturer. At termination points where the contact and loop conductors are out of sequence, it is better to add a pair than remove a pair to ensure alignment with the associated IDC.

This ensures that the pair lay distance within the cable can be maintained for the best possible transmission path. Excessive spread of IDC on-line pairs will impair the NEXT, FEXT and return loss performance of the Category 6 cabling system.

(i) Ambient temperature

The TIA and ISO standards conferences have raised the profile of this environmental issue. Of course it has caused problems in Category 5 and 5e in the past, and the industry believes that in Category 6 cabling it is a much more important issue.

The temperature of the environment in which the cable is installed does affect the transmission characteristics of the cable. If possible, avoid high temperature environments that may be encountered, eg >60°C. This can easily happen if the roof over the ceiling is exposed to direct sunlight. Generally speaking, the attenuation of the cable increases as the temperature increases. The effect on long links is that it can result in either a narrow pass or fail for this parameter.

(j) Summary

As you can see, in the installation parameters, there are no new major changes in Category 6 wiring compared to Category 5e wiring. To minimize the difficulty of installing a Category 6 system, it is important not to over-strengthen adhere to existing installation guidelines.

What are the common problems of six types of wiring

Question 1. Under what circumstances should you consider installing six types of products?

Answer: If considering the application requirements of the network in the future, theoretically the most advanced wiring products should be installed, because it is often difficult to update and replace after installing cables. Basically, a wiring system should be used for at least 10 years as a standard, and can support 4 to 5 years. The performance update of the network equipment, if the future network equipment needs better cables to increase the data speed.

Then, it is inevitable to replace Category 5e cables with Category 6 cables, but the rebuilding of these cables is very expensive, so even though the price of Category 6 products is slightly more expensive than Category 5e products, in order to reduce network upgrade problems in the future, Six categories of products are still worth considering.

Question 2. Can fiber-optic cables be used directly instead of Category 6 cables?

A: Of course you can do this, but fiber optic systems are extremely expensive and price is often a customer determining factor, today fiber optic cabling systems cost twice as much as Category 6 cabling. Also installing copper cables is simpler than installing fiber optic cables. In addition, copper cable products also support the DTE standard being drafted by IEEE (802.3af).

Question 3. What is the basic difference between the super five and six products?

A: The basic difference between Category 5 and Category 6 products lies in the improvement of transmission performance and bandwidth. The bandwidth of Category 5 is 100MHZ; the improvement of transmission performance including NEXT (near end crosstalk), RETURNLOSS (echo consumption) and ELFEXT (equivalent far end crosstalk) can greatly improve the ACR value, thereby improving the stability of the application. The system transmission speed can be improved.

Question 4. What are the advantages of Category 6 products over Category 5 products that can improve network performance?

A: Due to the improvement of transmission speed and superior anti-interference performance, Category 6 products can reduce the bit error rate more effectively than Category 5 products, thereby reducing the need for repeated transmission due to lost data packets, greatly improving the network performance. stability.

Question 5. Do Category 6 cables and connectors need to be matched to each other to form a "harmonious" wiring system?

A: Some cabling manufacturers advocate "harmonious" cabling systems to improve the system's margin performance, but this concept has not been included in the six categories of standards. In theory, the TIA standard only requires each component to pass Category 6 standards individually, which can ensure good link or channel performance.

The above is the whole content of what to pay attention to in the installation of six types of wiring and the common problems of six types of wiring, but in fact, seven types of wiring have appeared, but because of its cost and standard problems have not been popularized in our lives, so super Category 5 cabling and Category 6 cabling are still the mainstream in our network cabling.