1.2 Hardware Flashcards
Router
Connects different networks
Works at network layer
Stores net layout in a routing table
Switches
Similar to Router but send between individual devices on their LAN using MAC address.
Work at Data Link Layer
MAC Address
Media Access Control.
What switch is used onboard?
NavIS
Hubs
Read incoming packets and transmit outbound.
Works at Physical Layer.
Repeater
Similar to HUB but used to extend distance.
Works at Physical Layer.
Array
A storage system which contains multiple storage drives.
Features cache memory, RAID, encryption.
RAID
Redundant Array of Independant Disks
Provide protection and recovery from hardware defects and read errors.
We use RAID 5 (Distributed Parity), which requires at least 3 drives.
Works by striping the data and calculating a parity using XOR. If one drive fails, the parity can be used to calculate the missing bit and write it on a new drive to recover the data.
SAS
Serial Attached SCSI (Small Computer System Interface)
Connects storage arrays in CMS to computer systems IOT transfer data using serial signalling.
SATA II
Serial Advanced Technology Attachment
Connects storage arrays in CMS to computer systems IOT transfer data using serial signalling.
Cross compatible with SAS.
Shared SAS
Attaching a storage array to multiple servers.
Transmission mediums
Medium which propogates energy waves (EM, Sound)
Copper
Fibre
RF
Waveguides
Water
Twisted Pair Cabling
Two conductors are twisted together.
Unshielded Twisted Pair
Outer jacket
Ripcord
Twisted wires
Shielded Twisted Pair
3 types:
Foil on outer shell
Foil on each pair
Foil on both
Shielded Twisted Pair
3 types:
Foil on outer shell
Foil on each pair
Foil on both
CAT Cable
9 different types of Cat Cable.
Ethernet Naming: Physical mediums
T: Twisted Pair
F: Fibre Optic
S: Short Range Fibre
L: Long Range Fibre
K: Copper backplane
C: Balanced copper cable
B: Two wavelengths over single optical cable
S: Short range multi-mode optical cable
L: Long range optical cable
E: Extended range optical cable
Z: Long range single mode cable
Ethernet naming: Speeds
10 = 10 megabits
10G = 10 gigabits
Ethernet naming: Frequencies
BASE: Baseband - narrow freq range (single signal)
BROAD: Broadband - wide freq range (muliple signals)
PASS: Passband - regulated freq range (for multiplexing)
Encoding
X: 4B/5B block coding
R: 64B/66B block coding
Block Coding
4B/5B maps 4 bits of data onto groups of 5 bits for transmission. So it sends 5 bits in a 4 bit string because it has a table to convert.
Ethernet naming: 100 Base 1
Serial
Construction of COAX
Jacket
Shield
Insulator
Core
Ethernet Naming: T
Twisted Pair
Ethernet naming: F
Fibre Optic
Ethernet naming: S
Short Range Fibre
Ethernet Naming: L
Long Range Fibre (100m - 10km)