General Networking

Question 1

When should you use UTP?

Answer 1

When the permanent link and patch panels are UTP.

Question 2

When should you use STP?

Answer 2

When the permanent link and patch panels are STP.

Question 3

How can I tell if it is a UTP or STP installation/cable?

Answer 3

UTP connectors are typically made out of plastic while STP connectors are made from metal.

Question 4

What is PoE?

Answer 4

PoE stand for Power Over Ethernet. It is used to transfer electricity on a network cable to power devices like a desk telephone or an access point.

Question 5

What is the difference between PoE, PoE+ and PoE++?

Answer 5

PoE has a wattage of 15.4 watts. PoE+ has a wattage of up to 30 watts. PoE++ has a wattage of up to 100 watts.

Question 6

What is the transferrate/bandwidth of Cat. 8?

Answer 6

Cat. 8 has a maximum speed of 40Gbit/s (Gigabit per second). It is designed for data center and switch to switch communications. Maximum channel length is only 30m(!).

Question 7

What is the transferrate/bandwidth of Cat. 7?

Answer 7

Cat. 7 has a maximum speed of 10Gbit/s (Gigabit per second). Requires special connectors and sockets (GG45 or Siemon Tera).

Question 8

What is the transferrate/bandwidth of Cat. 6a?

Answer 8

Cat. 6a has a maximum speed of 10Gbit/s (Gigabit per second).

Question 9

What is the transferrate/bandwidth of Cat. 6?

Answer 9

Cat. 6 has a maximum speed of 1Gbit/s (Gigabit per second).

Question 10

What is the transferrate/bandwidth of Cat. 5e?

Answer 10

Cat. 5e has a maximum speed of 1Gbit/s (Gigabit per second).

Question 11

What is meant with bandwidth?

Answer 11

Bandwidth means the amount of data that can be transferred in a certain amount of time.

Question 12

What is OS2?

Answer 12

OS2 is single mode fiber optic.

Question 13

What is OM4?

Answer 13

OM4 is multi mode fiber optic.

Question 14

What is single mode good for?

Answer 14

Long distances (up to 80km).

Question 15

What is multi mode good for?

Answer 15

Short distances. Typcially within buildings as uplinks between racks.

Question 16

What does STP stand for?

Answer 16

STP stands for shielded twisted pair. Be aware, that the abbreviation STP does not specifiy the type of shield. In our case it is U/FTP.

Question 17

What does UTP stand for?

Answer 17

UTP stands for unshielded twisted pair.

Question 18

What is a switch?

Answer 18

A switch is an active component in a network that enables communication between connected devices.

Question 19

What is a channel?

Answer 19

A channel is a permanent link with a patch cord on each end.

Question 20

What is a permanent link?

Answer 20

A permanent link is a so called installation cable in buildings that typically runs from a patch panel to a outlet like on a desk.

Question 21

What is a patch panel?

Answer 21

A patch panel is a passive component in a network where all the permanent links are terminated to sockets that allow connecting a patch cord to it.

Question 22

What is a splice box?

Answer 22

A splice box is a patch panel for fiber optic.

Question 23

What is a UPS?

Answer 23

A Uninteruptible Power Supply (UPS) is a battery, typically placed in a network or server rack that continous to deliver power to connected devices during a blackout. This is important to properly shut down servers and not to lose data.

Question 24

What is the difference between a network and a server rack?

Answer 24

A server rack is typically narrower than a network rack as it does not have to deal with as many cables. Also server racks are more common in data centers where space is limited and expensive (cooling, redundant power, security etc).

Question 25

How does cable spaghetti happen?

Answer 25

By adding, removing patch cords with standard lengths or changing the port that a patch cord is connected to. It is a slow but steady process.

Question 26

Why not just use very short patch cords?

Answer 26

The ISO (International Standardization Organization) has ratified in the ISO/IEC11801 that a patch cord needs to be at least 50cm long.

Question 27

What is ISO/IEC11801?

Answer 27

ISO/IEC11801 is the standard for structured cabling that defines all criteria from form factors of connectors to transmission speeds etc.

Question 28

What are threaded hole racks?

Answer 28

This is a common type mainly used in the US. The 19" rail has threded holes where you directly insert a screw.

Question 29

What is a square punched hole rack?

Answer 29

This is a worldwide common type of rack. It has square punched holes in its 19" rail and requires a cage nut or /dev/mount to mount equipment.

Question 30

What is a cage nut?

Answer 30

A cage nut is a nut with mostly a M6 or M5 thread that is contained in a cage of spring steel. The cage needs to be pinched to be inserted in a 19" rail.

Question 31

What is a cable guide/cable management?

Answer 31

This typcially is a 19" device to be mounted in racks. It comes with hooks to guide and hold patch cords. Available as horizontal and vertical options.

Question 32

What is a DAC cable?

Answer 32

DAC stands for Direct Attached Copper cable. It is a copper cable with a SFP module on both ends. Mainly used as an uplink between active components. It allows speeds of up to 100Gbit/s.

Question 33

What is a SFP module?

Answer 33

A SFP is a fiber optic transceiver that converts optical signals into electrical signals. Typically used to connect a fiber optic to a switch.

Question 34

What is a Keystone Jack?

Answer 34

A keystone jack is used to terminate the end of a permanent link so you get a socket where you can plug cables in. Keystone Jacks are widely used nowadys and they can be inserted in either a patch panel or a outlet.

Question 35

What is LSA?

Answer 35

LSA was a termination method for permanent links used prior to Keystone Jacks. It required a special punching tool with which each wire was then terminated.

Question 36

What is a Uplink?

Answer 36

A uplink is a connection between two switches or two racks that allows communication between each other.

Question 37

What is a NAS?

Answer 37

NAS stands for Network Attached Storage. Back in the days these where pretty much just hard drives that you could connect to a network. Nowadays, NAS have become way more functionalities and can even act as servers.

Question 38

What is a server?

Answer 38

A server can be anything from a little Raspberry Pi to a several 100k€ expensive machine. A server provides services that hosts can rely on, like a mail or file server.

Question 39

What is a host?

Answer 39

A host is any end-point device in a network. Like your Laptop.

Question 40

What is RJ45?

Answer 40

RJ45 is the most common connector in a network. It has eight pins and a worldwide standardized form factor.

Question 41

What is RJ11?

Answer 41

RJ11 is the little brother of the RJ45 connector. It has a slightly smaller form factor and relies on only four pins/wires. You find it very often on the handset of a deskphone. It mainly is used for telephone applications.