Lesson 5: Objectives Flashcards
WAN interface is usually what?
How are they connected?
Point-to-point meaning there are only two devices connected to the media (unlike ethernet)
Ethernet connections are made using what?
(Hardware)
2
NIC’s and Switches.
WAN Interface is typically made by what kind of hardware?
Digital Modem
What are the 5 links to an internet connection>
- Hosts attached to a switch port or connected to the access point use ethernet and wi-fi to communicate
- SOHO wireless router implements all functions for local network and internet connectivity
- digital modem adapter in the router connects to an external line
- External line connects to the ISP’s PoP (Point of Presence)
- The ISP’s network forwards traffic over the internet
What establishes the physical connection to the WAN interface?
Modem
When interconnecting networks, there must be a way to identify each network and forwarding data between them. What performs this function?
the router
When interconnecting networks, there must be a way to identify each network and forwarding data between them. What is used as identification?
IP (Internet Protocol)
What “flavors” of DSL are there?
(Digital Subscriber Line)
(3)
S(symmetric)
A(Symmetric)
V(ery High Bit Rate)
What else is POTS known as?
local loop
last mile
ADSL provides what speed downlink and what speed uplink?
(Asymmetric DSL)
fast / slow not numbers
fast downlink
slow uplink
What kind of cabling is used for the core of the PSTN?
(Public Switched Telephone Network)
Fiber Optic Cable is dominant
What speed uplink and downlink does symmetric DSL offer?
fast / slow, not numeric
the same uplink and downlink speeds.
Is asymmetric or symmetric DSL more useful for businesses?
Symmetric, where more data is transferred upstream than with normal internet use.
On a standalone DSL modem, what kind of port on the modem connects to the phone point?
RJ-11 WAN port
What kind of port / interface is used on DSL modems to connect the modem to the router?
RJ-45
With DSL, what must be installed to each phone socket to separate voice and data signals?
Filter / Splitter
A CATV network is often described as what?
HFC hybrid fiber coax
HFC combines what?
(Hybrid Fiber Coax)
(Hardware)
(2)
fiber optic core network with copper coaxial cable links
What is the major obstacle to providing internet access that can perform like a LAN?
Bandwidth in the last mile
copper wiring infrastructure is often low-grade
What are the 5 connections on cable modem
- Cable Modem –> Local Router –> RJ-45
- AP’s Network w/short coax –> Threaded F-Type Connector
- Coax links all premises in a street with CMTS
- Forwards data traffic w/fiber backbone to ISP’s PoP
- To the Internet
AP Access Point
CMTS Cable Modem Termination System
PoP Point of Presence
The cable modem is interfaced to the local router with what kind of port?
RJ-45
CATV / HFC can also be described as what?
Cable Access TV / Hybrid Fiber Coax
Broadband cable
cable
DOCSIS v3 allows the use of what to achieve higher bandwidth?
multiplexed channels
What benefit does LEO (Low Earth Orbit) Satellites have over traditional satellites?
Lower RTT / Latency time
What type of DSL achieves the highest bit rates?
VDSL
Very High Bit Rate DSL
What kind of cable / connector is a cable modem connected to the Access Providers network with?
Short segment of coax
terminated using threaded F-type connectors
What does the ONT do? (Optical Network Terminal)
Converts the fiber optic signal to an electrical one.
In a PON (Passive Optical Network), what kind of cable is run, and from what point to what point?
a single fiber cable is run from an OLT (Optical Line Terminal) to a splitter.
In a PON (Passive Optical Network), where does the splitter direct traffic to?
Splitter directs each subscribers traffic over a shorter length of fiber to an ONT (Optical Network Terminal)
Where is the ONT? (Optical Network Terminal)
installed at the customer’s premises.
What is the ONT connected to? Using What? (Optical Network Terminal)
Connected to the customer’s router using an RJ-45 Copper Wire Patch Cord
What is one drawback of satellites placed in a high geostationary orbit?
increased latency
because the signal must travel over thousands of miles more than terrestrial connections, giving a greater delay
Where are the orbital satellites located
Over the equator
(Pointing south for the northern hemisphere for satellites and pointing north for the southern hemisphere)
How is satellite internet connected?
(3)
- ISP installs a VSAT (Very small aperture terminal) satellite dish antenna at the customers premises
- ISP aligns the VSAT with the orbital Satellite.
- Antenna is connected via coaxial cable to DVB-S Modem (Digital Video Broadcast Satellite)
What is the drawback of LEO (Low Earth Orbit) Satellites?
LEO (Low Earth Orbit) Satellites move relative to Earth so the customers antenna must have a motor to periodically realign with the satellite.
Antenna must have a clear view of the whole sky
WISP (Wireless Internet Service Provider) uses what kind of wireless technology?
ground-based long-range fixed access wireless technology
WISP (Wireless Internet Service Provider) installs and maintains a directional antenna to work as a bridge between the customer’s network and the ISP.
might use Wi-Fi type networking or proprietary equipment
Do WISP’s (Wireless Internet Service Provider) use licensed or unlicensed frequency bands?
Both
what is the disadvantages of fixed access wireless (Wisp (Wireless Internet Service Provider))
(2)
the actual unobstructed line of sight between the two antennas can be difficult to maintain.
If the ISP uses unlicensed frequencies, there are risks of interference from other wireless networks and devices
All types of microwave radio link can be adversely affected by what?
(3)
snow
rain
high winds
With 3G Cellular Wireless, how does the radio make a connection?
to the nearest base station.
With 3G Cellular Wireless, the area served by ease base station is referred to as what?
a “cell”
With 3G Cellular Wireless, what is the effective range of each cell?
5 miles
8 km
though signals can be obstructed by building materials.
With 3G Cellular Wireless, there are two competing formats
- GSM (Global System for Mobile Communication)
- CDMA (Code Division Multiple Access)
With 3G Cellular Wireless, what is the difference between GSM (Global System for Mobile communication) and CDMA? (Code Division Multiple Access)
- GSM: Phones allow subscribers to use SIM cards to unlock handset with chosen network provider
- CDMA: handset is directly managed by the provider and there is no removable SIM
(Global System for Mobile communication)
(Subscriber Identity Module)
(Code Division Multiple Access)
With 3G Cellular Wireless, UMTS (Universal Mobile Telecommunications Service) is used on what format?
GSM Global System for Mobile communication
H/H+ / HSPA (High Speed Packet Access) is used with what kind of cellular network?
3G
With 3G Cellular Wireless, EV-DO (Evolution Data Optimized) is used on what format phone?
GSM VS CDMA
CDMA Cell Division Multiple Access
Is 4G LTE supported by GSM or CDMA network providers?
both
5G uses what?
different spectrum bands from low to medium/high.
low bands = greater range and penetrating power
high bands = close range and cannot penetrate walls and windows
What makes rolling out 5G wireless complex?
Rather than a single large antenna serving a wide area, 5G requires many smaller antennas to form an array that can take advantage of multipath and beamforming to overcome propagation limits of the spectrum.
5G technology is referred to as what?
Massive MIMO Multiple Input Multiple Output
What serves as both the protocol needed to connect to the internet and the system interface?
Device
Router
What forwards a MAC (hardware) address?
a switch
A MAC address identifies what?
a hardware port
what forwards packets to the internet using IP addresses?
routers
What does a LAN router do? (Local Area Network)
(2)
- divides a single physical network into multiple logical subnetworks
- each logical network becomes a separate broadcast domain.
An IP address contains what information? (2)
- the identity of both the network and
- a single host within that network.
What kind of interfaces does a LAN router typically have?
ethernet only
what kind of interface does a WAN router have? (2)
- ethernet interface for local network
- digital modem interface for the WAN
The role of filtering allowed and denied hosts and protocols is performed by what?
a network firewall
What is a security benefit of a LAN router?
traffic passing from one logical network to another can be subject to filtering rules.
what does a WAN or border Router do?
forwards traffic to and from the internet or over a private WAN link.
Each entry in a network firewalls ACL (Access Control List) (rules) lists what? (3)
- the source and/or destination network address
- protocol types and
- whether or not to allow or block traffic that matches that rule
basic firewall rules is referred to as what?
network access control list
Most networks use what kind of protocol Suite?
TCP / IP
(Transmission Control Protocol / Internet Protocol)
The function of each TCP / IP protocol is better understood by diving network functions into layers.
What are the 4 network layers?
Application
Transport
Internet
Link/Network Interface
The function of each TCP / IP protocol is better understood by diving network functions into layers.
Name some examples of the Application Layer: (14)
- DHCP
- DNS
- FTP
- HTTP/HTTPS
- SMTP
- IMAP
- POP3
- SSH
- RDP
- Telnet
- LDAP
- SNMP
- Syslog
The function of each TCP / IP protocol is better understood by diving network functions into layers.
Name 2 examples of the Transport layer:
- TCP
- UDP
The function of each TCP / IP protocol is better understood by diving network functions into layers
Name an example of the internet layer
IP
The function of each TCP / IP protocol is better understood by diving network functions into layers.
Name 2 examples of the Link / Network Interface Layer
- Ethernet
- Wi-Fi
The function of each TCP / IP protocol is better understood by diving network functions into layers.
Regarding the Link / Network Interface Layer: What is this layer responsible for?
Putting frames onto the physical network.
The function of each TCP / IP protocol is better understood by diving network functions into layers.
What Layer would DSL work under?
The Link / Network Interface Layer
The function of each TCP / IP protocol is better understood by diving network functions into layers.
What layer would cable modems work at?
The Link / Network Interface Layer
The function of each TCP / IP protocol is better understood by diving network functions into layers.
Regarding the Link / Network Interface Layer: What protocols are used on this layer?
Does not contain TCP/IP Protocols
The function of each TCP / IP protocol is better understood by diving network functions into layers.
Regarding the Link / Network Interface Layer: Where do communications take place on this layer?
Only at the local level and not between networks.
The function of each TCP / IP protocol is better understood by diving network functions into layers.
Regarding the Internet Layer: What does the IP provide?
packet addressing and routing within a network of networks.
The function of each TCP / IP protocol is better understood by diving network functions into layers.
Regarding the Internet Layer: For data to be sent from one network to another, it must be forwarded by what?
an intermediate system (Router)
The function of each TCP / IP protocol is better understood by diving network functions into layers.
Regarding the Internet Layer: IP provides what?
Best effort delivery that’s unreliable and connectionless. a packet might be lost, delivered out of sequence, duplicated, or delayed.
The function of each TCP / IP protocol is better understood by diving network functions into layers.
Regarding the Transport Layer: What does the transport layer do?
determines how each host manages multiple connections for different application layer protocols at the same time.
The function of each TCP / IP protocol is better understood by diving network functions into layers.
Regarding the Internet Layer: What does the internet layer deal with
Addressing
The function of each TCP / IP protocol is better understood by dividing network functions into layers.
Regarding the Transport Layer: TCP provides what kind of packet forwarding?
Transmission Control Protocol
guarantees connection-oriented forwarding of packets.
The function of each TCP / IP protocol is better understood by diving network functions into layers.
Regarding the Transport Layer: What does TCP do that makes it more reliable than UDP
Transmission Control Protocol
User Datagram Protocol
TCP can identify and recover from lost or out of order packets.
The function of each TCP / IP protocol is better understood by diving network functions into layers.
Regarding the Transport Layer: what kind of applications tend to us UDP
User Datagram Protocol
time-sensitive applications such as speech or video.
The function of each TCP / IP protocol is better understood by diving network functions into layers.
Regarding the Transport Layer: is TCP or UDP faster?
UDP
because it doesn’t need to send extra information to establish reliable connections.
The function of each TCP / IP protocol is better understood by diving network functions into layers.
Regarding the Application Layer: what is the purpose of the application layer protocols?
they perform high-level functions beyond addressing and sending data. Used to configure and manage network hosts and to operate services.
What does the IP in the TCP / IP protocol provide?
network and host addressing and packet forwarding between networks.
The function of each TCP / IP protocol is better understood by diving network functions into layers.
Regarding the Transport Layer: How reliable is UDP Forwarding?
User Datagram Protocol
unreliable and connectionless forwarding.
How many bits is an IPv4 address?
32 bits long.
In an IPv4 address: what two pieces of information are encoded within the same value?
The network ID
The host ID
How can an IPv4 address be arranged?
into 4 groups of 8 bits (one byte) eg.
11000000101010000000000000000001
11000000 10101000 00000000 00000001
IPv4 addresses are made easier to use by putting them in dotted decimal notation. how is this done?
by converting each octet into a decimal value
In an IPv4 address, what identifies a host within a particular IP network?
host ID
In an IPv4 address what identifies the network common to all hosts on the same IP network?
Network ID
When a host attempts to send a packet via IPv4, the protocol compares what?
the source and destination IP address in the packet against the sending host’s subnet mask.
if the masked portions of the source and destination IP address match, then the destination interface is assumed to be on the same IP network or subnet.
On Ethernet, the host would use what to identify the MAC address associated with the destination IP address (In IPv4 forwarding)
Protocol
address resolution protocol (ARP)
IPv4 forwarding, If the masked portion does not match the source and destination IP:
the host assumes that the packet must be routed to another IP network. It would be forwarded to the a router rather than trying to deliver it locally.
Public IP Addresses are permitted to do what?
Packets with public addresses are permitted to be forwarded over the internet.
The default gateway configured to most hosts must be what?
in the same IP network as the host.
Packets with private IP addresses should be what?
blocked at internet gateways or forwarded using some type of translation mechanism
Public IP addresses are allocated to who by whom?
Customer Networks by
ISP’s
There are 3 ranges of private IPv4 addresses that aren’t allowed to route traffic over the public internet. These addresses are confined to what?
Private LAN’s
What range is the Class A private address IPv4 Range:
10.0.0.0 to 10.255.255.255