Week 5 - POTS and Dial-Up and Broadband Connections and Fiber Flashcards
What is PSTN? What is it also called?
Public Switched Telephone Network
also called POTS
What does modem stand for?
Modulator demodulator
How does a dial-up modem work?
It transfers bits of data into audible wavelengths sent over POTS
What is a baud rate?
baud rate is the measurement of how many bits can be passed across a phone line in a second
What is broadband?
Broadband describes anything that isn’t a dial-up connection
What are T-carrier technologies? Who invented it?
Invented by AT&T, it transmits multiple phone calls over a single link
How many simultaneous phone call connections are there in a single T1 connection?
24
What’s the transfer speed of a T1 connection?
1.544 megabits a second
What’s the connection speed of an AT3/T3?
44.736 megabits per second
What are DSLAMS?
Digital Subscriber Line Access Multiplexers
modems for DSL lines
What does ADSL and SDSL stand for?
Asymmetrical digital subscriber lines
Symmetrical digital subscriber lines
What is HDSL?
High bitrate digital subscriber line
has speeds over 1.544 mb/s
What’s the difference between SDSL and ADSL?
ADSL - faster download, slower upload speed
SDSL - same download and upload speed
How does cable broadband not interfere with TV broadcasts signals?
Cable broadband uses frequencies that don’t interfere with TV signals
What type of cable is a coaxial cable?
shared bandwidth technology between users until it reaches ISPs core network
What is a CO and what does a CO look like now?
CO is a building to which subscriber home/business lines are connected to on a local loop
CO now has automated hardware that handles this function
What is a cable modem?
The cable modem device sits at the edge of the consumer network and connects it to the CMTS
What connects CMTS to a consumer’s network?
cable modem
What is CMTS?
cable modem termination system
connects different cable connections to an ISP’s core network
What technology used CO? How was the bandwidth?
Central offices were/are used by dial-up and DSL connections and guaranteed a certain amount of bandwidth
What is FTTX?
Fiber to the X, x can mean many things
What is FTTN?
Fiber to the neighborhood
delivers fiber to a single cabinet for certain population
What is FTTB?
fiber to the building/basement/business
twisted copper wires are used to connect everyone inside the building after
What is FTTP?
fiber to the premises
FTTB and FTTH can be called FTTP
What is ONT?
ONT is optical network terminator
converts data from protocols the fiber networks use to something the twisted copper wires can understand
What is FTTH?
Fiber to the home
fiber to each individual home/apartment
What does PPP stand for?
Point to Point Protocol
what does CHAP stand for? (authentication)
Challenge Handshake Authentication Protocol
What layer does PPP work on?
Data Link Layer
What is PPP? Between how many linked devices?
The main function of PPP is to transport encapsulated L3 protocols over serial links (between 2 directly linked devices ONLY)
What are the 4 PPP configuring options?
- Multilink
2.Compression - Authentication
- Error detection
What are the 2 sub protocols for PPP on the network layer?
NCP network control protocol
LCP link control protocol
How is PPP data sent?
PPP data is encapsulated in a frame
What do you call the demarcation point for fiber technologies?
ONT
What is the NCP for PPP? What does it do?
Network Control Protocol
NCP helps the router determine how to transport the encapsulated L3 protocols
(NCP and LCP protocols control L3)
What is the LCP for PPP? What 5 PPP configurations does it help with?
Link Control Protocol
- auto start/ends connections for hosts link establishment
- authentication
- error detection
- load balancing
- multilink
What does CHAP do?
CHAP is a 3 way handshake authentication that periodically confirms the client’s identity
Challenge Handshake Authentication Protocol
What does PAP stand for? What does it do?
PAP stands for password authentication protocol
uses passwords to validate users
What does the Flag do in a PPP frame?
1 byte - lets receiver know this is the beginning of the frame
(there may be a start/end flag)
What does the Address field in a PPP frame contain?
1 byte - contains broadcast address
What does the Control field in a PPP frame contain?
1 byte - allows a connectionless data link
What does the Protocol field in a PPP frame contain?
1-3 bytes - identify network protocol of datagram
What’s the data size limit of a PPP frame?
1500 bytes per frame
What does FCS stand for and what does it do?
Frame Check Sequence
Makes sure that data was delivered/received intact without error
What does PPPoE stand for?
Point-to-Point Protocol over Ethernet
What does PPPoE do?
PPPoE encapsulates the PPP frame into an ethernet frame
What authentication does PPPoE use most?
PPPoE uses (PAP) password authentication protocol the most
What does it mean when something is multi-access enabled?
Multi-access means that every node connects to another
What are 2 ways PPPoE is used?
- PPPoE using DSL services from a DSL modem/router connecting to DSL
- PPPoE DSL modem connected to PPPoE only router via ethernet cable
What is the discovery stage in terms of PPPoE?
The discovery stage establishes a session ID to identify the hardware address
Why is the discovery stage for PPPoE important?
The discovery stage ensures that data gets delivered to the right place
What’s the difference between PPP and PPPoE?
PPPoE is an extra layer of encapsulation for standard PPP frames, that allows data to be sent over ethernet connections
