Let’s have a look at structured cabling. Download PowerPoint: Structured Cabling Structured cabling is a collection of standardized components for networking. They are defined under the ANSI/TIA standards. For the A+ exam, you only really need to have a basic understanding of how networking components are connected together. It is unlikely that you will get a difficult question on this topic. To understand how a site may be cabled up, let’s have a look at some of the components and how they are connected together. Let’s first consider that your business has an external connection to the internet. In this example, it has a fiber optic connection to the internet. The fiber cable will need to terminate somewhere on the business site. This location is called a demarcation point or demarc. These demarcation points can look very different from site to site. Often, they are located in a room on the ground floor or basement. Let’s now consider how the business connects to the telephone network. In this example, the business connects to a telephone exchange. To do this, there are a number of phone lines running from the business to the exchange. In this example, these phone lines are terminated at punch blocks. Punch blocks are often used for telephone installations as they allow quick changes to the wiring by punching the wires down into the block and position required. A special punch down tool is used to punch the wiring into place. The point where phone wires from outside the building connect to the internal wiring is called the demarcation point. This is where the public network ends and the customer’s network starts. However, to make it easier to make changes, these may be connected to a Main Distribution Frame or MDF. It is important to point out that every site is different. It is not uncommon for the MDF and demarc point to be in the same set of punch down blocks. Usually, the first group of punch down blocks will be the incoming lines. The upper block numbers are going to the cabling running to the customer’s patch panels or their internal wiring. As businesses grow, there may not be enough punch blocks, and more are then added. As existing punch blocks become full, newer external lines may need to be installed at the end of the punch panel rather than at the start. Don’t assume that external lines will always be the first punch blocks. Most MDFs will have documentation to explain what wires go where, but often this documentation is not kept up to date. So, don’t assume anything. Hopefully, your MDF will just be a patch panel making it easy to make changes. The MDF will generally be in close proximity to where the external cables come into the building. I have seen cases where fiber lines terminated at a patch panel. Thus, the demarc and MDF are in the same rack. I have also seen one site where there was a room large enough to park two cars in. In the center of the room was a small box where the external fiber line terminated. The room contained only a single fiber optic box. Another fiber optic line ran from this box to a nearby room housing the MDF. Description too long for YouTube. Please see the following link for the rest of the description. References “The Official CompTIA A+ Core Study Guide (Exam 220-1101)” page 136 “Mike Myers All in One A+ Certification Exam Guide 220-1101 & 220-1102” pages 781 to 759 “Picture: 110 phone block” : “Picture: Network rack” : “Picture: Patch Panel” “Picture: Network switches” : “Picture: Roof cabling” “Picture: Cable pit” :2021-04-08_M%C3% Credits Trainer: Austin Mason Voice Talent: HP Lewis Quality Assurance: Brett Batson