2.7 Compare & contrast internet connection types, network types, & their features Flashcards
6 types of Internet connections?
- Satellite
- Fiber
- Cable
- DSL
- Cellular
- WISP
Typical uplink bandwidth for satellite internet?
6Mbps
Typical downlink bandwidth for satellite internet?
30Mbps
1 drawback of satellite internet?
Increase latency
The signal travels much farther than terrestrial connections, resulting in significant delays compared to land links.
What is Round Trip Time (RTT)?
2-way latency for sending a probe & receiving a response
Probe: Data packet sent to measure network charactersitics like latency or packet loss
How is a satellite internet connection created?
ISP installs & aligns a VSAT dish satellite at customer’s premises
It is aligned with the orbital satellite
Satellite Internet
What cabling is used to connect the satellite to the modem?
satellite internet uses DVB-S modems
Coaxial cabling
How does LEO satellite internet differ from regular satellite internet?
LEO = Low Earth Orbit
Using satellites positioned in much closer to earth
Typical LEO satellite internet bandwidth?
100Mbps
Typical latency of LEO satellite internet?
200ms RTT
Downside to LEO satellite internet?
Customer’s antenna needs a motor for periodic realignment
It’s realigned with satellites
Dish uses phased array tech to connect to passing satellites, reducing realignment.
Meaning of WISP?
Wireless ISP
What technology do WISPS use?
Ground-based long-range fixed wireless technology
How does a WISP provide internet?
Using a directional antenna to bridge the customer’s & provider’s network
WISPS have lower latency than satellite internet
WISPS may use licensed or unlicensed frequency bands
Problem with using unlicensed frequencies?
High chance of interference
What occurances affect all types of microwave radio links?
i.e. Point-to-point microwave links, satellite communication links, etc.
Snow, rain, & high winds
What does a 3G cellular radio device establish a connection with?
Nearest base station
What is a 3G cell?
Area covered by a 3G base station
Max range of a 3G cell?
5 miles
Signals can be obstructeed by building materials
What frequency bands does 3G cellular radio operate in the Americas?
850 & 1,900 MHz
These lower frequency waves don’t need much power to propagate over long distances
What frequency bands does 3G cellular radio operate in the world (besides the Americas)?
900 & 1,800 MHz
These lower frequency waves don’t need much power to propagate over long distances
What is LTE?
4G standard supported by GSM & CDMA providers
What frequency bands does 5G use?
- sub-6 GHz
- 20-60 GHz
Benefit of low RF bands?
i.e. sub-6GHz (5G frequency band)
Greater range & penetration power than medium/high RF bands
Drawback to medium/high RF bands?
Require close range & cannot penetrate walls or windows
(range is about a few hundred feet)
Why does 5G involve using many small antennas?
To utilize multipath & beamforming to improve propagation
This technology is referred to as MIMO
this means using multiple paths and adjusting the direction of signals to improve how signals travels
What technology does 5G use?
MIMO (Multiple Input Multiple Output)
What is a LAN?
Group of computers connected at one location with cables & switches
A LAN might span a single floor in a building, a whole building, or multiple nearby buildings. LAN cabling & devices are typically owned & managed by the organization that uses the network
How long can a node be to be considered “local” (LAN)?
Up to about 1 mile (1 or 2 km)
Meaning of IEEE?
Institute of Electrical & Electronics Engineers
What standards are most cabled LANs based on?
802.3 Ethernet standards
What designation scheme do IEEE 802.3 standards use?
xBASE-Y
What does x in xBASE-Y mean?
Nominal data rate
What does Y in xBASE-Y mean?
Cable type
What does 100BASE-T mean?
(Ethernet designation scheme)
Fast Ethernet over copper twisted pair cabling
Fast Ethernet = 100Mbps
How fast is Fast Ethernet?
100 Mbps
What does 1000BASE-T mean?
(Ethernet designation scheme)
Gigabit Ethernet over copper twisted pair cabling
How fast is Gigabit Ethernet?
1000 Mbps (1 Gbps)
What does 10GBASE-T mean?
(Ethernet designation scheme)
Copper cabling working at 10 Gbps
Which 802.3 Ethernet designation scheme is mainstream for wired LANs?
1000BASE-T
2 types of cabling used in Ethernet?
- Copper
- Fiber optic
How does copper differ from fiber optic?
Using electrical signaling to communicate data
How does Fiber optic differ from Copper?
Using pulses of light to communicate data
How do WLANs work?
WLAN = Wireless LAN
Using radios & antennas for data transmission
Wi-Fi (802.11) & Ethernet technologies complement one another & are often used together as segments within the same local network
What is 802.11 aka?
Wi-Fi
Meaning of WAN?
Wide Area Network
Meaning of LAN?
Local Area Network
How far does a WAN span?
Multiple geographic locations
i.e. the Internet (A network of networks).
What cabling do most private/enterprise WANs use?
Cabling leased from an ISP to connect LANs
i.e. a company might use a WAN to connect branch office sites to the LAN at its head office
Meaning of SOHO?
Small Office Home Office
What is a “server room”?
Area where servers are hosted
What is a datacenter?
Whole site that is dedicated to provisioning server resources
How do datacenters differ from “server rooms”?
By having networking, power, climate control, & physical access control features
Meaning of SAN?
Storage Area Network
Where is a SAN located?
Within an enterprise LAN or datacenter
purpose of SANs?
Provide access to a pool of storage devices for application servers
What devices only access SANs?
Servers
Not by client PCs/laptops
A SAN is isolated from the main network
What kind of devices are SAN clients?
Meaning the devices that are in a SAN
Servers running databases or applications
What is a SAN more flexibe & reliable than?
Using local disks on each server machine
2 types of connectivity used by SANs?
- Fiber Channel
- Internet SCSI (iSCSI)
Meaning of PAN?
Personal Area Network
What is a PAN?
Network to connect devices within a few meters
A PAN facilitates data sharing among PCs, mobile devices, and wearables such as smartwatches. It connects these devices to peripherals like printers, headsets, and displays.