Computer Networks

Flow control is the responsibility of?

Which one of the following layers of abstraction is not present in the TCP/IP (Transmission Control Protocol/Internet Protocol) model but is included in the OSI model?

How many bits are required to represent IPv4 address in any IPv4 header?

Which one of the following functionalities do TCP and UDP have in common?

What type of application would prefer UDP transport service?

Which one of the following statements is true about Go-Back-N (GBN) protocol?

Which one of the following statements is true about Selective Repeat (SR) protocol?

Which one of the following statements is true about TCP's "Slow Start" algorithm?

In which computer network topology, a single cable is used, through which all data propagates and to which all computers and networked nodes are connected?

Bluetooth is the wireless technology for -

List, in order, the layers of the TCP/IP protocol stack, and briefly write the functions provided by each layer. Also give an example of a protocol or networking technology associated with each layer.

Draw the IPV4 Datagram Header Format and explain it.

What are the differences in the treatment of collisions in CSMA/CD (Carrier Sense Multiple Access, with Collision Detection) and CSMA/CA (Carrier Sense Multiple Access, with Collision Avoidance)?

Write down the sender-side steps and the receiver-side steps in Cyclic Redundancy Check (CRC) method, with examples.

Explain why Slotted ALOHA approach performs better than pure ALOHA approach?

In a Slotted ALOHA system, suppose there are 5 nodes, in which each node transmits a frame with probability $ p $. What is the probability that in a given time slot, one of the nodes successfully transmits a frame?

Consider a sender S and a receiver R that are connected on a network, where the one-way latency is 250 milliseconds. The data rate of that network is 32000 bits per second, and size of each frame in that network is 1000 bits. Assume that S and R are using sliding windows with Selective Repeat. How large must the sliding window for S be in order to maximize the utilization?

Discuss Link-State routing protocol with an example.

Explain count-to-infinity problem associated with distance vector routing. Discuss the countermeasures taken in Split Horizon and Poison Reverse techniques.

An ISP is granted the block 80.70.56.0/21. The ISP needs to allocate addresses for 2 organizations each 500 addresses, 2 organizations each with 250 addresses and 3 organizations each with 50 addresses. Design a subnet and find the range of addresses and unallocated addresses for each organization.

Compare any two the following: (i) TCP and UDP. (ii) Packet switching and Circuit switching (iii) Bit-stuffing and Byte-stuffing

Consider a router receiving an IP packet of header size 20 Bytes (having no optional fields) and payload size of 4000 Bytes. Now the router must now transmit this packet across an Ethernet network, which has Maximum Transmission Unit (MTU) of 1500 Bytes. If the router attempts to send the maximum payload bits permissible in each attempt, how fragmentation is to be carried out to transmit the IP packet in the Ethernet network?

What are the differences between leaky bucket algorithm and token bucket algorithm?

Write down the handshaking steps required to setup a TCP connection between two applications running on two end-hosts A and B. Also, write down the purpose of each data unit of TCP that is sent and received for establishing TCP connection.

Write down the similarities and differences between Hyper-Text Transfer Protocol (HTTP) and File Transfer Protocol (FTP).

Hamming distance

DNS

DHCP

Telnet

Flow control is the responsibility of?

Which one of the following layers of abstraction is not present in the TCP/IP (Transmission Control Protocol/Internet Protocol) model but is included in the OSI model?

How many bits are required to represent IPv4 address in any IPv4 header?

Which one of the following functionalities do TCP and UDP have in common?

What type of application would prefer UDP transport service?

Which one of the following statements is true about Go-Back-N (GBN) protocol?

Which one of the following statements is true about Selective Repeat (SR) protocol?

Which one of the following statements is true about TCP's "Slow Start" algorithm?

In which computer network topology, a single cable is used, through which all data propagates and to which all computers and networked nodes are connected?

Bluetooth is the wireless technology for -

List, in order, the layers of the TCP/IP protocol stack, and briefly write the functions provided by each layer. Also give an example of a protocol or networking technology associated with each layer.

Draw the IPV4 Datagram Header Format and explain it.

What are the differences in the treatment of collisions in CSMA/CD (Carrier Sense Multiple Access, with Collision Detection) and CSMA/CA (Carrier Sense Multiple Access, with Collision Avoidance)?

Write down the sender-side steps and the receiver-side steps in Cyclic Redundancy Check (CRC) method, with examples.

Explain why Slotted ALOHA approach performs better than pure ALOHA approach?

In a Slotted ALOHA system, suppose there are 5 nodes, in which each node transmits a frame with probability $ p $. What is the probability that in a given time slot, one of the nodes successfully transmits a frame?

Consider a sender S and a receiver R that are connected on a network, where the one-way latency is 250 milliseconds. The data rate of that network is 32000 bits per second, and size of each frame in that network is 1000 bits. Assume that S and R are using sliding windows with Selective Repeat. How large must the sliding window for S be in order to maximize the utilization?

Discuss Link-State routing protocol with an example.

Explain count-to-infinity problem associated with distance vector routing. Discuss the countermeasures taken in Split Horizon and Poison Reverse techniques.

An ISP is granted the block 80.70.56.0/21. The ISP needs to allocate addresses for 2 organizations each 500 addresses, 2 organizations each with 250 addresses and 3 organizations each with 50 addresses. Design a subnet and find the range of addresses and unallocated addresses for each organization.

Compare any two the following: (i) TCP and UDP. (ii) Packet switching and Circuit switching (iii) Bit-stuffing and Byte-stuffing

Consider a router receiving an IP packet of header size 20 Bytes (having no optional fields) and payload size of 4000 Bytes. Now the router must now transmit this packet across an Ethernet network, which has Maximum Transmission Unit (MTU) of 1500 Bytes. If the router attempts to send the maximum payload bits permissible in each attempt, how fragmentation is to be carried out to transmit the IP packet in the Ethernet network?

What are the differences between leaky bucket algorithm and token bucket algorithm?

Write down the handshaking steps required to setup a TCP connection between two applications running on two end-hosts A and B. Also, write down the purpose of each data unit of TCP that is sent and received for establishing TCP connection.

Write down the similarities and differences between Hyper-Text Transfer Protocol (HTTP) and File Transfer Protocol (FTP).

Hamming distance

DNS

DHCP

Telnet

In the following pairs of OSI protocol layer/sub-layer and its functionality, the INCORRECT pair is:

Which of the following is NOT true with respect to a transparent bridge and a router?

Which one of the following statements is FALSE?

Which one of the following statements is FALSE?

In a sliding window ARQ scheme, the transmitter's window size is N and the receiver's window size is M. The minimum number of distinct sequence numbers required to ensure correct operation of the ARQ scheme is

Which one of the following protocols is NOT used to resolve one form of address to another one?

Identify the correct sequence in which the following packets are transmitted on the network by a host when a browser requests a webpage from a remote server, assuming that the host has just been restarted.

How many bytes of data can be sent in 15 seconds over a serial link with baud rate of 9600 in asynchronous mode with odd parity and two stop bits in the frame?

Which one of the following is TRUE interior Gateway routing protocols - Routing Information protocol(RIP) and Open Shortest Path First (OSPF)?

In the slow start phase of the TCP congestion control algorithm, the size of the congestion window:

Suppose that the stop-and-wait protocol is used on a link with a bit rate of 64 kilobits per second and 20 milliseconds propagation delay. Assume that the transmission time for the acknowledgment and the processing time at nodes are negligible. What is the minimum frame size in bytes to achieve a link utilization of at least 50%.

Consider an instance of TCP's Additive Increase Multiplicative Decrease (AIMD) algorithm where the window size at the start of the slow start phase is 2 MSS and the threshold at the start of the first transmission is 8 MSS. Assume that a timeout occurs during the fifth transmission. Find the congestion window size at the end of the tenth transmission.

The address of a class B host is to be split into subnets with a 6-bit subnet number: What is the maximum number of subnets and the maximum number of hosts in each subnet? What is the number of network allowed under Class B addresses?

Assume that source S and destination D are connected through two intermediate routers labelled R. Determine how many times each packet has to visit the network layer and the data link layer during a transmission from S to D.

In an IPv4 datagram, the M bit is 0, the value of HLEN is 10, the value of total length is 400 and the fragment offset value is 300. Find the position of the datagram, the sequence numbers of the first and the last bytes of the payload respectively.

An IP router with a Maximum Transmission Unit (MTU) of 1500 bytes has received an IP packet of size 4404 bytes with an IP header of length 20 bytes. The values of the relevant fields in the header of the third IP fragment generated by the router for this packet are?

A serial transmission T1 uses 8 information bits, 2 start bits, 1 stop bit and 1 parity bit for each character. A synchronous transmission T2 uses 3 eight bit sync characters followed by 30 eight bit information characters. If the bit rate is 1200 bits/second in both cases, what are the transfer rates of T1 and T2?

Compare and contrast the Go-Back-N ARQ Protocol with Selective-Repeat ARQ.

What are the advantages of fiber optics over copper as a transmission medium? Is there any downside of using fiber optics over copper?

A computer on a 6-Mbps network is regulated by a token bucket. The token bucket is filled at a rate of 1 Mbps. It is initially filled to capacity with 8 megabits. How long can the computer transmit at the full 6 Mbps?

DNS uses UDP instead of TCP. If a DNS packet is lost, there is no automatic recovery. Does this cause a problem, and if so, how is it solved?

Explain the responsibility of network and transport layers of OSI model with example.

What are the functions of a RIP message? List the RIP shortcomings and their corresponding fixes.

Describe the functions of the two FTP connections. What kinds of file types can FTP transfer?

Compare the TCP header and the UDP header. List the fields in the TCP header that are missing from UDP header. Give the reason for their absence.

What is the difference between open-loop congestion control and closed-loop congestion control?

In the following pairs of OSI protocol layer/sub-layer and its functionality, the INCORRECT pair is:

Which of the following is NOT true with respect to a transparent bridge and a router?

Which one of the following statements is FALSE?

Which one of the following statements is FALSE?

In a sliding window ARQ scheme, the transmitter's window size is N and the receiver's window size is M. The minimum number of distinct sequence numbers required to ensure correct operation of the ARQ scheme is

Which one of the following protocols is NOT used to resolve one form of address to another one?

Identify the correct sequence in which the following packets are transmitted on the network by a host when a browser requests a webpage from a remote server, assuming that the host has just been restarted.

How many bytes of data can be sent in 15 seconds over a serial link with baud rate of 9600 in asynchronous mode with odd parity and two stop bits in the frame?

Which one of the following is TRUE interior Gateway routing protocols - Routing Information protocol(RIP) and Open Shortest Path First (OSPF)?

In the slow start phase of the TCP congestion control algorithm, the size of the congestion window:

Suppose that the stop-and-wait protocol is used on a link with a bit rate of 64 kilobits per second and 20 milliseconds propagation delay. Assume that the transmission time for the acknowledgment and the processing time at nodes are negligible. What is the minimum frame size in bytes to achieve a link utilization of at least 50%.

Consider an instance of TCP's Additive Increase Multiplicative Decrease (AIMD) algorithm where the window size at the start of the slow start phase is 2 MSS and the threshold at the start of the first transmission is 8 MSS. Assume that a timeout occurs during the fifth transmission. Find the congestion window size at the end of the tenth transmission.

The address of a class B host is to be split into subnets with a 6-bit subnet number: What is the maximum number of subnets and the maximum number of hosts in each subnet? What is the number of network allowed under Class B addresses?

Assume that source S and destination D are connected through two intermediate routers labelled R. Determine how many times each packet has to visit the network layer and the data link layer during a transmission from S to D.

In an IPv4 datagram, the M bit is 0, the value of HLEN is 10, the value of total length is 400 and the fragment offset value is 300. Find the position of the datagram, the sequence numbers of the first and the last bytes of the payload respectively.

An IP router with a Maximum Transmission Unit (MTU) of 1500 bytes has received an IP packet of size 4404 bytes with an IP header of length 20 bytes. The values of the relevant fields in the header of the third IP fragment generated by the router for this packet are?

A serial transmission T1 uses 8 information bits, 2 start bits, 1 stop bit and 1 parity bit for each character. A synchronous transmission T2 uses 3 eight bit sync characters followed by 30 eight bit information characters. If the bit rate is 1200 bits/second in both cases, what are the transfer rates of T1 and T2?

Compare and contrast the Go-Back-N ARQ Protocol with Selective-Repeat ARQ.

What are the advantages of fiber optics over copper as a transmission medium? Is there any downside of using fiber optics over copper?

A computer on a 6-Mbps network is regulated by a token bucket. The token bucket is filled at a rate of 1 Mbps. It is initially filled to capacity with 8 megabits. How long can the computer transmit at the full 6 Mbps?

DNS uses UDP instead of TCP. If a DNS packet is lost, there is no automatic recovery. Does this cause a problem, and if so, how is it solved?

Explain the responsibility of network and transport layers of OSI model with example.

What are the functions of a RIP message? List the RIP shortcomings and their corresponding fixes.

Describe the functions of the two FTP connections. What kinds of file types can FTP transfer?

Compare the TCP header and the UDP header. List the fields in the TCP header that are missing from UDP header. Give the reason for their absence.

What is the difference between open-loop congestion control and closed-loop congestion control?

(a) Network layer of OSI model does not establish any relationship among different packets of same message. (Write True or False)

(b) What is repeater?

(c) What is baud rate?

(d) What is switch?

(e) What is flooding in routing?

(f) What is TCP?

(g) What is the role of a bridge?

(h) What do you mean by connectionless service?

(i) List two protocols in channelization category.

(j) What is byte-oriented protocol?

Explain the responsibilities of first four layers of OSI model.

Compare between TCP/IP and OSI models.

Explain the transmission characteristics of twisted pair.

Compare and contrast between byte-oriented and bit-oriented protocols. Also compare between byte-stuffing and bit-stuffing.

Explain the reasons for moving from stop-and-wait ARQ protocol to Go-back-N ARQ protocol.

Define framing and discuss the reasons for its need. What are fixed-size and variable-size framings?

Draw the flow diagram for the CSMA/CD and explain. Also compare CSMA/CD with ALOHA.

What is bridge? Explain about spanning tree.

What are the common Gigabit Ethernet implementations?

Explain the procedure for checksum and verification in the IPv4 protocol. What part of an IPv4 packet is covered in the checksum calculation and why? Are options, if present, included in the calculation?

Discuss the types of ICMP messages.

Discuss four types of link defined by OSPF. What is the basis of classification for the four types of link defined by OSPF?

List RIP shortcomings and their corresponding fixes.

TCP is sending data at 2 Mbytes/sec. If the sequence number starts with 7000, how long does it take before the sequence number goes back to zero?

Explain connection establishment in TCP using three-way handshaking.

(a) Network layer of OSI model does not establish any relationship among different packets of same message. (Write True or False)

(b) What is repeater?

(c) What is baud rate?

(d) What is switch?

(e) What is flooding in routing?

(f) What is TCP?

(g) What is the role of a bridge?

(h) What do you mean by connectionless service?

(i) List two protocols in channelization category.

(j) What is byte-oriented protocol?

Explain the responsibilities of first four layers of OSI model.

Compare between TCP/IP and OSI models.

Explain the transmission characteristics of twisted pair.

Compare and contrast between byte-oriented and bit-oriented protocols. Also compare between byte-stuffing and bit-stuffing.

Explain the reasons for moving from stop-and-wait ARQ protocol to Go-back-N ARQ protocol.

Define framing and discuss the reasons for its need. What are fixed-size and variable-size framings?

Draw the flow diagram for the CSMA/CD and explain. Also compare CSMA/CD with ALOHA.

What is bridge? Explain about spanning tree.

What are the common Gigabit Ethernet implementations?

Explain the procedure for checksum and verification in the IPv4 protocol. What part of an IPv4 packet is covered in the checksum calculation and why? Are options, if present, included in the calculation?

Discuss the types of ICMP messages.

Discuss four types of link defined by OSPF. What is the basis of classification for the four types of link defined by OSPF?

List RIP shortcomings and their corresponding fixes.

TCP is sending data at 2 Mbytes/sec. If the sequence number starts with 7000, how long does it take before the sequence number goes back to zero?

Explain connection establishment in TCP using three-way handshaking.