Week 6: Day 019 - Installing a Physical Network #3

Well, be prepared for yet another short entry. My school was put on lockdown cause of some report of "shots fired", so I got here pretty late. And don't even get me started with yesterday. The bus didn't even show up cause they didn't care to send one, and I was taking PSAT's which lasted four hours! Anyways, this week is a shorter one anyway cause of Columbus Day. Aside from that stuff, things are back to normal, so let's get right into this.

So last time I left off on Network Interface Unit (NIU). I said I couldn't be bothered cause there was only 10 minutes left in class, and there wasn't a stopping point that was near enough. This is part of the whole "demarc" thing I was talking about before. So the NIU which is provided by ISP's serve as a "demarc" in your home. There is usually a network interface box for this type of stuff as well. However, in office buildings it's much different. This is for obvious reasons, like the fact that you have to serve many more computers and telephones. These days companies have "smart jacks" in their NIUs so they can tell if the customer is connected to the NIU. It also has good use for loopback testing by giving people remote ways of doing it. After the demarc of network and telephone cables have to connect to a box, that of the customer, which acts a distribution tool throughout the building. The cabling from the NIU to the box which is that of the customer is usually called "demarc extension". Telephones however have a "multiplexer", and for LAN it's connected to a powerful switch. The said switch is usually connected to a patch panel. The patch panel is then connected to the telecommunications room. The main patch pannel is known as a "vertical cross-connect". Telephone systems use vertical cross-connects as well. A lot of UTP cables feed into it. Now, that's a lot of equipment we're talking about: demarc, telephone cross-connects, and LAN cross-connects. So where do you put it??? Well you put it in an MDF (main distribution frame) which distinguishes it from multiple IDF (telecommunications room) rooms. Now every building does not have a single demarc, MDF, or multiple IDFs, so what do you do then? Well the fact of the matter is that every installing operation is unique and needs different types of installation or adaptation. Like for example, you may have one IDF room, and one extra room that you could use to combine demarc and MDF. So this is a big reminder that when installing a network, every situation is different. Next time I will talk about "Installing Structured Cabling", but with such a short period of time to do this entry thanks to the lockdown, I can't write that much. Thanks for reading, and tschuss!