CSE 310 MIDTERM REVIEW EXAM
QUESTIONS AND ANSWERS 100% PASS
What is the Internet? - ANS - "Network of networks"
- infrastructure that provides services to applications
- provides programming interface to apps
Protocol - ANS - controls sending and receiving of messages
- set of invisible computer rules that govern how an internet document gets transmitted to your
screen
Access Network - ANS - network that physically connects an end system to the first router on
a path form the end system to any other distant end system
Examples:
- Home Access - DSL, Cable, Dial-Up, Satellite
- Access in Enterprise and Home - Wi-Fi and Ethernet
- Wide-area Wireless Access - 3G or LTE
DSL - ANS - Digital Subscriber Line
- use existing telephone line to central office DSLAM
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,Cable Network - ANS - Frequency division multiplexing: different channels transmitted in
different frequency bands
Enterprise Access Networks (Ethernet) - ANS - typically used in companies, universities, etc.
Wireless Access Networks - ANS - shared wireless access network connects end system to
router via base station aka "access point"
- wireless LANs: within building
- wide-area wireless access: provided by cellular operator
Physical Link - ANS - what lies between transmitter and receiver
- Guided Media: twisted-pair copper wire, coaxial cable, fiber optics
- Unguided Media (signal carried in electromagnetic spectrum; no physical wires): terrestrial
radio channels, satellite radio channels
The Network Core - ANS - packet switching, circuit switching, a network of networks
Packet Switching - ANS - break long messages into packets
- store-and-forward transmission
- queuing delays and packet loss
- forwarding tables and routing protocols
Formula Needed for Packet Switching - ANS R (bit/sec) = full transmission rate of the link
L (bits) = packet size
Transmission Time (sec) = L/R
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, Circuit Switching - ANS - the resources must be reserved
- multiplexing in circuit-switching networks: FDM and TDM
Store-and-Forward Transmission - ANS - packet switch must receive the entire packet
3 packets and 2 links. What is the time to receive all 3 packets? - ANS 4L/R
If L = 7.5 Mbits and R = 1.5 Mbps. What is the transmission time? - ANS 5 sec
Key Network-core Functions - ANS routing and forwarding
Routing - ANS - determines source-destination route taken by packets (routing algorithms)
Forwarding - ANS - move packets from router input to appropriate router output
Queuing and Packet Loss - ANS - if arrival rate (in bits) to link exceeds transmission rate of
line for a period of time:
- packets will queue, wait to be transmitted
on link
- packets can be dropped (lost) if memory
(buffer) fills up
FDM - ANS - Frequency Division Multiplexing
- technique for sending two or more signals over the same telephone line, radio channel, or
other medium
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
QUESTIONS AND ANSWERS 100% PASS
What is the Internet? - ANS - "Network of networks"
- infrastructure that provides services to applications
- provides programming interface to apps
Protocol - ANS - controls sending and receiving of messages
- set of invisible computer rules that govern how an internet document gets transmitted to your
screen
Access Network - ANS - network that physically connects an end system to the first router on
a path form the end system to any other distant end system
Examples:
- Home Access - DSL, Cable, Dial-Up, Satellite
- Access in Enterprise and Home - Wi-Fi and Ethernet
- Wide-area Wireless Access - 3G or LTE
DSL - ANS - Digital Subscriber Line
- use existing telephone line to central office DSLAM
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
,Cable Network - ANS - Frequency division multiplexing: different channels transmitted in
different frequency bands
Enterprise Access Networks (Ethernet) - ANS - typically used in companies, universities, etc.
Wireless Access Networks - ANS - shared wireless access network connects end system to
router via base station aka "access point"
- wireless LANs: within building
- wide-area wireless access: provided by cellular operator
Physical Link - ANS - what lies between transmitter and receiver
- Guided Media: twisted-pair copper wire, coaxial cable, fiber optics
- Unguided Media (signal carried in electromagnetic spectrum; no physical wires): terrestrial
radio channels, satellite radio channels
The Network Core - ANS - packet switching, circuit switching, a network of networks
Packet Switching - ANS - break long messages into packets
- store-and-forward transmission
- queuing delays and packet loss
- forwarding tables and routing protocols
Formula Needed for Packet Switching - ANS R (bit/sec) = full transmission rate of the link
L (bits) = packet size
Transmission Time (sec) = L/R
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, Circuit Switching - ANS - the resources must be reserved
- multiplexing in circuit-switching networks: FDM and TDM
Store-and-Forward Transmission - ANS - packet switch must receive the entire packet
3 packets and 2 links. What is the time to receive all 3 packets? - ANS 4L/R
If L = 7.5 Mbits and R = 1.5 Mbps. What is the transmission time? - ANS 5 sec
Key Network-core Functions - ANS routing and forwarding
Routing - ANS - determines source-destination route taken by packets (routing algorithms)
Forwarding - ANS - move packets from router input to appropriate router output
Queuing and Packet Loss - ANS - if arrival rate (in bits) to link exceeds transmission rate of
line for a period of time:
- packets will queue, wait to be transmitted
on link
- packets can be dropped (lost) if memory
(buffer) fills up
FDM - ANS - Frequency Division Multiplexing
- technique for sending two or more signals over the same telephone line, radio channel, or
other medium
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
