How to select Network jumper in network cabling

Usually LAN LAN used by the jumper mainly from three channels: first, with the overall link products with the brand matching jumper; second, on-site production jumper; third, purchase the jumper in the computer market. In addition to matching jumper can obtain the professional testing of manufacturers, the general user is difficult to know the site production or market purchase jumper quality status. The quality of the jumper will seriously affect the network transmission efficiency and network stability, and fake and shoddy products in conjunction with the attached hardware (computer or switch interface) produces irreversible damage, resulting in the entire system paralysis.





below we compare the status of jumpers under these three channels from several aspects, and analyze the results from various jumpers ' structure, fabrication process and materials.





Project Brand finished jumper spot production jumper market purchase jumper





Transmission Performance (electrical performance) Good poor individual difference big





Reliability (network connection) Good poor unknown





High price low unknown





compatibility (with network card, connecting hardware) Good poor individual difference big





flexibility (distance length) good poor





service life is unknown





the use of convenience is very poor unknown





jumper structure mainly from the jumper cable conductor, Crystal Head, protective sets of these three aspects, the following first let us more intuitive look at the finished jumper and on-site production of the jumper in kind contrast (left is the finished jumper, the right is the field production jumper).





1, Brand finished jumper





standard requirements for the production of finished jumper cable conductor AWG26 (7/0.16mm) or AWG24 (7/0.20mm) of the bare soft copper stranded wire. This structure of the cable is relatively soft, good bending, to ensure that the jumper in the use of the process is very convenient. At the same time because it is stranded copper wire, the site is easier to line. With fluke selection jumper monomer test, RL, next performance allowance exceeds the TIA568B standard to the factory.





finished jumper because it belongs to a brand with network cable and connection hardware, it is easier to keep the characteristic impedance of the whole channel consistent, so as to get the ideal RL value.





2, on-site production jumper




The
site is used to make jumper cables, which are generally the remaining fraction lines of the horizontal wiring. Horizontal cable conductor structure is a solid conductor, cat5e using AWG24 (1/0.511mm), Cat6 using AWG23 (1/0.574mm) bare soft copper single line. The cable of this kind of structure is relatively hard, the bending is poor, the spot line is more difficult. In addition, because the on-site installation of the Crystal Head is the use of hand-pressure simple crimping tools, crystal Head and solid conductor of the bonding reliability and the operation of the pressure operator has a greater relationship, on-site production of jumper performance, with Fluke Select jumper monomer Test, RL, next performance of individual differences are very large, And the reliability of the mechanical connection point is obviously worse than the brand finished jumper.





3, market purchase jumper





Market to buy jumpers due to a variety of channels, for jumper products to understand not very professional users, and even may buy a live production of jumpers. Even if the purchase of brand jumper, there may be "cottage" goods. The author has found in a project site customers used to test the jumper cable structure of 5/0.16mm stranded aluminum wire, the jumper identified as a well-known brand products. With fluke selection of jumper monomer test, RL, next performance margin is almost less than -10.0db, this is obviously a fake and inferior products, but also in the general market when the purchase is very easy to encounter problems.





second, jumper raw material analysis





to meet the tia/eia568b.2 standard requirements of the jumper performance, must use high-quality raw materials. The jumper covers the raw material including jumper cable and Crystal Head two parts:





1, jumper cable





Conductor is the use of oxygen-free round copper rods, resistivity <0.017241; insulation using HDPE, better brands such as UCC3364;





General matching jumpers and on-site production of jumpers in the material can meet the requirements, but the market procurement jumper is difficult to guarantee. The material cost of some inferior jumpers on the market is very low, and the performance can only ensure the conduction. The main embodiment is:





Conductor Aspect: The market purchase jumper may use aluminum, also may use is inferior copper, this kind of conductor resistivity is big, the ductility is poor;





Insulation: The more likely to use the general HDPE insulating materials, may be used to the use of materials, the dielectric constant of this type of material is large and unstable, elongation is small. In addition to almost no electrical performance, this type of jumper also has a short life, poor reliability of the shortcomings.





2, Crystal Head





RJ45 Connector (Crystal Head) of the metal film is mainly used phosphor bronze nickel and then gold-plated, general gold-plated thickness of 30u ", 50u", six types of crystal Head gold layer thickness is generally 50u "(1.27μm), the requirements of the Crystal Head plug 750 times the performance does not fall; plastic shell for PC, According to the Ul-94-v0, the requirements of crystal Head shrapnel plug more than 750 times does not break.





matching brand product jumper Crystal Head metal sheet, gold-plated layer and plastic shell materials are in the factory internal standards have been tested to ensure that the product mechanical electrical performance requirements. On-site production of jumper used crystal Head if the original products from matching, quality can be guaranteed, if the crystal Head is purchased on the market, the material mechanical, electrical, fire performance is difficult to guarantee.





below let's compare two crystal head: Sample A is a supporting manufacturer to provide products, sample B for the market to buy an international well-known brand products. Sample A (left) metal plate color is dim, close to Gold color, sample B (right) metal plate color is brighter, similar to brass color (metal plate surface has obvious spots), sample a plastic shell transparent and uniform, sample b transparent and white, and have slight cracks.