Objective 2.4 Flashcards
Given a scenario, use appropriate physical installation considerations. (16 cards)
What is an MDF (Main Distribution Frame)?
The primary, central wiring point for a building’s or campus’s network.
It’s where external network connections, like the internet service from an ISP, enter the building and connect to the internal network backbone.
It’s the top of the structured cabling hierarchy.
What is an IDF (Intermediate Distribution Frame)?
A secondary, auxiliary wiring closet that connects to the MDF.
IDFs are typically located on each floor of a building or in different sections of a large facility.
They connect the backbone cabling from the MDF to the horizontal cabling that goes to individual workstations.
What is the Demarcation Point (Demarc)?
The precise physical point where the public network of a service provider (like an ISP) ends and the private network of the customer begins.
This is a critical point of responsibility—the provider is responsible for everything before the demarc, and the customer is responsible for everything after it.
What is a Rack Unit (U)?
A standard unit of measure for the height of equipment designed for rack mounting.
1U = 1.75 inches.
A 42U rack, for example, has 42 units of vertical space for equipment.
What is the difference between a Two-Post Rack and a Four-Post Rack?
- Two-Post Rack: Has two vertical supports. Best for lighter equipment that doesn’t have much depth, like patch panels and network switches.
- Four-Post Rack: Has four vertical supports, creating a deeper, more stable cage. It is essential for heavy, deep equipment like servers, which are supported by server rails.
What are Server Rails?
Adjustable mounting kits that attach to the four posts of a rack.
They support the full depth and weight of a server or other heavy device, often allowing the device to slide out for easy maintenance without being removed from the rack.
What is a Free-standing Rack?
A self-contained equipment rack, often fully enclosed with doors and side panels.
These are also commonly called cabinets.
They offer greater security and controlled airflow compared to open-frame racks.
What is a Hot Aisle / Cold Aisle layout?
A data center design that improves cooling efficiency.
Racks are arranged in rows where all cold air intakes face one direction (the cold aisle) and all hot air exhausts face the opposite direction (the hot aisle).
This prevents hot exhaust from being recycled back into equipment intakes.
What does Port-side exhaust/intake mean for a network switch?
It describes the airflow direction of the switch.
For a hot/cold aisle layout to work, you must use switches whose airflow direction matches the design (e.g., in a cold aisle, you need switches that pull cool air in from the port-side and exhaust hot air out the back).
What are the two primary functions of a UPS (Uninterruptible Power Supply)?
- Backup Power: Provides temporary, instantaneous battery power during a utility power failure, allowing for graceful shutdown of equipment.
- Power Conditioning: Protects equipment from power fluctuations like sags, surges, and brownouts by providing clean, stable power.
What is an RPS (Redundant Power Supply)?
A feature where a critical network device (like a core switch or server) has two or more internal power supply units.
If one power supply fails, the other(s) automatically take over the full load with no downtime.
This provides fault tolerance for the device itself.
What is a PDU (Power Distribution Unit)?
A device designed to distribute electric power within a rack.
- Basic PDU: A professional-grade power strip.
- Managed/Switched PDU: A “smart” PDU that allows for remote monitoring of power consumption and the ability to remotely turn individual outlets on or off.
Why is proper Grounding essential in a server room?
To safely dissipate electrostatic discharge (ESD), which can damage sensitive electronic components.
It also provides a safe path for fault currents in case of an electrical short, protecting both equipment and personnel.
What is the best practice for Labeling network infrastructure?
Label everything at both ends with a clear, consistent, and well-documented naming scheme.
This includes patch cables, wall jacks, patch panel ports, and the network devices themselves.
Good labeling saves enormous amounts of time during troubleshooting.
What is the difference between Horizontal and Vertical Cable Management?
Horizontal Cable Management: Organizes patch cables running between devices within a rack, such as from a patch panel down to a switch.
Vertical Cable Management: Organizes the large bundles of cables running up and down the sides of a rack, connecting it to other racks or to the building’s cabling infrastructure.
What is a key feature of Fire Suppression Systems used in data centers?
They must be able to extinguish a fire without damaging the electronic equipment.
This is why gas-based systems (like FM-200 or Inergen) that displace oxygen are preferred over traditional water-based sprinklers, which would destroy the equipment.
