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Computer networks Questions with Detailed Verified
Answers
Protocols Ans: ✓ ✓ ✓ define format, order of messages sent and received among network entities,
and actions taken on message transmission, receipt
Digital Subscriber Line (DSL) Ans: ✓ ✓ ✓ use existing telephone line to central office DSLAM
data over DSL phone line goes to Internet
voice over DSL phone line goes to telephone net
< 2.5 Mbps upstream transmission rate (typically < 1 Mbps)
< 24 Mbps downstream transmission rate (typically < 10 Mbps)
cable network Ans: ✓ ✓ ✓ frequency division multiplexing: different channels transmitted in
different frequency bands
HFC: hybrid fiber coax • asymmetric: up to 30Mbps downstream transmission rate, 2 Mbps
upstream transmission rate
network of cable, fiber attaches homes to ISP router
homes share access network to cable headend
unlike DSL, which has dedicated access to central office
Enterprise Access Networks (Ethernet) Ans: ✓ ✓ ✓ 10 Mbps, 100Mbps, 1Gbps, 10Gbps
transmission rates
Wireless access networks Ans: ✓ ✓ ✓ Shared wireless access network connects end system to
router
--via base station aka "access point"
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Wireless LANs Ans: ✓ ✓ ✓ within building
802.11b/g/n (WiFi): 11, 54, 450 Mbps transmission rate
wide-area wireless access Ans: ✓ ✓ ✓ -Provided by telco (cellular) operator, 10's km
-Between 1 and 10 Mbps
-3G, 4G: LTE
packet transmission delay Ans: ✓ ✓ ✓ L(bits)/R(bits/sec) R is transmission rate, L is length of
packets in bits.
Packet Switching Ans: ✓ ✓ ✓ hosts break application-layer messages into packets
store and forward Ans: ✓ ✓ ✓ entire packet must arrive at router before it can be transmitted on
next link
queuing and loss Ans: ✓ ✓ ✓ If arrival rate (in bits) to link exceeds transmission rate of link for a
period of time:
packets will queue, wait to be transmitted on link
packets can be dropped (lost) if memory (buffer) fills up
routing Ans: ✓ ✓ ✓ determines source destination route taken by packets
forwarding Ans: ✓ ✓ ✓ move packets from router's input to appropriate router output
Circuit Switching Ans: ✓ ✓ ✓ end-end resources allocated to, reserved for "call" between source &
dest
Packet switching versus circuit switching Ans: ✓ ✓ ✓ packet switching allows more users to use
network
Four sources of packet delay Ans: ✓ ✓ ✓ Nodal Processing
Queueing Delay
Transmission Delay
Propagation Delay
© Get it right 2025 Getaway - Stuvia US All rights reserved
Computer networks Questions with Detailed Verified
Answers
Protocols Ans: ✓ ✓ ✓ define format, order of messages sent and received among network entities,
and actions taken on message transmission, receipt
Digital Subscriber Line (DSL) Ans: ✓ ✓ ✓ use existing telephone line to central office DSLAM
data over DSL phone line goes to Internet
voice over DSL phone line goes to telephone net
< 2.5 Mbps upstream transmission rate (typically < 1 Mbps)
< 24 Mbps downstream transmission rate (typically < 10 Mbps)
cable network Ans: ✓ ✓ ✓ frequency division multiplexing: different channels transmitted in
different frequency bands
HFC: hybrid fiber coax • asymmetric: up to 30Mbps downstream transmission rate, 2 Mbps
upstream transmission rate
network of cable, fiber attaches homes to ISP router
homes share access network to cable headend
unlike DSL, which has dedicated access to central office
Enterprise Access Networks (Ethernet) Ans: ✓ ✓ ✓ 10 Mbps, 100Mbps, 1Gbps, 10Gbps
transmission rates
Wireless access networks Ans: ✓ ✓ ✓ Shared wireless access network connects end system to
router
--via base station aka "access point"
© Get it right 2025 Getaway - Stuvia US All rights reserved
, Click here for more: Scholars nexus
Wireless LANs Ans: ✓ ✓ ✓ within building
802.11b/g/n (WiFi): 11, 54, 450 Mbps transmission rate
wide-area wireless access Ans: ✓ ✓ ✓ -Provided by telco (cellular) operator, 10's km
-Between 1 and 10 Mbps
-3G, 4G: LTE
packet transmission delay Ans: ✓ ✓ ✓ L(bits)/R(bits/sec) R is transmission rate, L is length of
packets in bits.
Packet Switching Ans: ✓ ✓ ✓ hosts break application-layer messages into packets
store and forward Ans: ✓ ✓ ✓ entire packet must arrive at router before it can be transmitted on
next link
queuing and loss Ans: ✓ ✓ ✓ If arrival rate (in bits) to link exceeds transmission rate of link for a
period of time:
packets will queue, wait to be transmitted on link
packets can be dropped (lost) if memory (buffer) fills up
routing Ans: ✓ ✓ ✓ determines source destination route taken by packets
forwarding Ans: ✓ ✓ ✓ move packets from router's input to appropriate router output
Circuit Switching Ans: ✓ ✓ ✓ end-end resources allocated to, reserved for "call" between source &
dest
Packet switching versus circuit switching Ans: ✓ ✓ ✓ packet switching allows more users to use
network
Four sources of packet delay Ans: ✓ ✓ ✓ Nodal Processing
Queueing Delay
Transmission Delay
Propagation Delay
© Get it right 2025 Getaway - Stuvia US All rights reserved
