Demarcation Point

Where the ISPs connect ends and our network begins
Also called entrance facility

Backbone Switch

Connects to all the devices in the network
From the Demarcation Point a cable is run to the border gateway (router) from where it is connected to the backbone switch

Edge Switch

Switch that is closer to the end user and connects back to the backbone switch using a trunk line

Main Distribution Frame (MDF)

A telecommunications closet that acts as the starting point for all the interior cabling
The backbone switch will be located in the MDF

Intermediate Distribution Frame (IDF)

Contains an edge switch, edge router, a patch panel and other associated equipment to support the floor or office nearest to it

Punch Down Block

Located inside MDF and IDF
The back of Patch Panels make use of Punch Down Blocks as well

66 Block (M Block): Used in older analog telephone systems. Where designed a 25 pair cable that came from the phone company
110 Block: Supports high speed data network for CAT 5 and above
Krone Block: Proprietary European alternative to 110 Block
BIX Block: Another proprietary punch down block

Patch Panel

Keeps a data center or server room organized by making it easy to modify the cable distribution infrastructure
Fiber Patch Panels do not have punch down blocks on the back there will have one of the jacks that are supported to fiber cables