11/3/25, 1:30 PM Computer Networking
Computer Networking Newest Version 2025-2026
\Latest Update with Complete questions and
accurate answers
R1. Let's review some of A network-layer packet is a datagram. A router
the terminology used in this forwards a packet based on the packet's IP (layer 3)
textbook. Recall that the address. A link-layer switch forwards a packet based
name of a transport-layer on the packet's MAC (layer 2) address.
packet is segment and that
the name of a link-layer
packet is frame. What is the
name of a network-layer
packet? Recall that both
routers and link- layer
switches are called packet
switches. What is the
fundamental difference
between a router and link-
layer switch?
Recall that we use the term
routers for both
datagram networks and VC
networks.
R2. What are the two The two functions of datagram-based network layer are
most important network- path determination and switching. The additional
layer functions in a function of a vc-based network is call setup.
datagram network?
What are the three
most important
network-layer functions
in a virtual-circuit
network?
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,11/3/25, 1:30 PM Computer Networking
Forwarding is about moving a packet from a router's
R3. What is the difference
input link to the appropriate output link. Routing is
between routing and
about determining the end-to-routes between sources
forwarding?
and destinations.
R4. Do the routers in both Yes, both use forwarding tables. For descriptions of the tables,
datagram networks and see Section 4.2.
virtual-circuit network use
forwarding tables? If so,
describe the forwarding
tables for both classes of
networks.
R5. Describe some ...
hypothetical services that
the network layer can
provide to a single packet.
Do the same for a flow of
packets. Are any of can
provide to a single packet.
Do the same for a flow of
packets. Are any of your
hypothetical service
provided by the Internet's
network layer? Are any
provided by ATM's CBR
service model? Are any
provided by ATM's ABR
service model?
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,11/3/25, 1:30 PM Computer Networking
Single packet: guaranteed delivery; guaranteed delivery
with guaranteed maximum delay. Flow of packets: in-
R6. List some applications
order packet delivery; guaranteed minimal bandwidth;
that would benefit from
guaranteed maximum jitter. None of these services is
ATM's CBR service model.
provided by the Internet's network layer. ATM's CBR
service provides both guaranteed delivery and timing.
ABR does not provide any of these services.
With the shadow copy, the forwarding decision is
R7. Discuss why each input
made locally, at each input port, without invoking the
port in a high- speed router
centralized routing processor. Such decentralized
stores shadow copy of the
forwarding avoids creating a forwarding processing
forwarding table.
bottleneck at a single point within the
router.
R8. Three types of Switching via memory; switching via a bus; switching via an
switching fabrics are interconnection network
discussed in Section 4.3.
List and briefly describe
each type. Which, if any, can
send multiple packets
across the fabric in
parallel.
R9. Describe how packet Packet loss occurs if queue size at the input port
loss can occur at input grows large because of slow switching fabric speed
ports. Describe how and thus exhausting router's buffer space. It can be
packet loss at input ports eliminated if the switching fabric speed is at least n times
can be eliminated (without as fast as the input line speed, where n is the number
using infinite buffers). of input ports.
R10. Describe how packet Packet loss can occur if the queue size at the output
loss can occur at input port grows large because of slow outgoing line-
ports. Describe how speed.
packet loss at input ports
can be eliminated (without
using infinite buffers).
HOL blocking - a queued packet in an input queue must
R11. What is HOL blocking?
wait for transfer through the fabric because it is blocked
Does it occur in input ports
by another packet at the head of the line. It occurs at
or output port?
the input port.
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, 11/3/25, 1:30 PM Computer Networking
R12. Do router have IP Yes. They have one address for each interface.
addresses? If so, how
many?
R13. What is the 32-bit binary 11011111 00000001 00000011 00011100
equivalent of the IP address
223.1.3.27?
R14. Visit a host that uses 8 interfaces; 3 forwarding tables
DHCP to obtain its IP
address, network mask,
default router, and IP
address of its local DNS
server. List
these values.
/ 4/129
Computer Networking Newest Version 2025-2026
\Latest Update with Complete questions and
accurate answers
R1. Let's review some of A network-layer packet is a datagram. A router
the terminology used in this forwards a packet based on the packet's IP (layer 3)
textbook. Recall that the address. A link-layer switch forwards a packet based
name of a transport-layer on the packet's MAC (layer 2) address.
packet is segment and that
the name of a link-layer
packet is frame. What is the
name of a network-layer
packet? Recall that both
routers and link- layer
switches are called packet
switches. What is the
fundamental difference
between a router and link-
layer switch?
Recall that we use the term
routers for both
datagram networks and VC
networks.
R2. What are the two The two functions of datagram-based network layer are
most important network- path determination and switching. The additional
layer functions in a function of a vc-based network is call setup.
datagram network?
What are the three
most important
network-layer functions
in a virtual-circuit
network?
/ 1/129
,11/3/25, 1:30 PM Computer Networking
Forwarding is about moving a packet from a router's
R3. What is the difference
input link to the appropriate output link. Routing is
between routing and
about determining the end-to-routes between sources
forwarding?
and destinations.
R4. Do the routers in both Yes, both use forwarding tables. For descriptions of the tables,
datagram networks and see Section 4.2.
virtual-circuit network use
forwarding tables? If so,
describe the forwarding
tables for both classes of
networks.
R5. Describe some ...
hypothetical services that
the network layer can
provide to a single packet.
Do the same for a flow of
packets. Are any of can
provide to a single packet.
Do the same for a flow of
packets. Are any of your
hypothetical service
provided by the Internet's
network layer? Are any
provided by ATM's CBR
service model? Are any
provided by ATM's ABR
service model?
/ 2/129
,11/3/25, 1:30 PM Computer Networking
Single packet: guaranteed delivery; guaranteed delivery
with guaranteed maximum delay. Flow of packets: in-
R6. List some applications
order packet delivery; guaranteed minimal bandwidth;
that would benefit from
guaranteed maximum jitter. None of these services is
ATM's CBR service model.
provided by the Internet's network layer. ATM's CBR
service provides both guaranteed delivery and timing.
ABR does not provide any of these services.
With the shadow copy, the forwarding decision is
R7. Discuss why each input
made locally, at each input port, without invoking the
port in a high- speed router
centralized routing processor. Such decentralized
stores shadow copy of the
forwarding avoids creating a forwarding processing
forwarding table.
bottleneck at a single point within the
router.
R8. Three types of Switching via memory; switching via a bus; switching via an
switching fabrics are interconnection network
discussed in Section 4.3.
List and briefly describe
each type. Which, if any, can
send multiple packets
across the fabric in
parallel.
R9. Describe how packet Packet loss occurs if queue size at the input port
loss can occur at input grows large because of slow switching fabric speed
ports. Describe how and thus exhausting router's buffer space. It can be
packet loss at input ports eliminated if the switching fabric speed is at least n times
can be eliminated (without as fast as the input line speed, where n is the number
using infinite buffers). of input ports.
R10. Describe how packet Packet loss can occur if the queue size at the output
loss can occur at input port grows large because of slow outgoing line-
ports. Describe how speed.
packet loss at input ports
can be eliminated (without
using infinite buffers).
HOL blocking - a queued packet in an input queue must
R11. What is HOL blocking?
wait for transfer through the fabric because it is blocked
Does it occur in input ports
by another packet at the head of the line. It occurs at
or output port?
the input port.
/ 3/129
, 11/3/25, 1:30 PM Computer Networking
R12. Do router have IP Yes. They have one address for each interface.
addresses? If so, how
many?
R13. What is the 32-bit binary 11011111 00000001 00000011 00011100
equivalent of the IP address
223.1.3.27?
R14. Visit a host that uses 8 interfaces; 3 forwarding tables
DHCP to obtain its IP
address, network mask,
default router, and IP
address of its local DNS
server. List
these values.
/ 4/129
