MauryaHub PYQ Practice

cs4024_2026T1_ET_FN.pdf

Computer Networks · End Term · Jan 2026 FN

← Course papers · Start practice / exam

Questions and published explanations below are available without starting a test. Some questions may not have a published solution yet.

Question 2 MCQ · 1.0 marks

When using Dijkstra’s algorithm to find shortest path in a graph, which of the following statement is not true?
  1. It can find shortest path within the same graph data structure
  2. Every time a new node is visited, we choose the node with smallest known distance/cost (weight) to visit first
  3. Shortest path always passes through least number of vertices
  4. The graph needs to have a non-negative weight on every edge

A published solution is not available for this question yet.

Question 3 MCQ · 1.0 marks

The browser establishes a TCP connection with the server, but displays a blank page or keeps loading indefinitely. What is the MOST likely issue?
  1. The server did not call listen()
  2. The HTTP response is missing proper headers (e.g., Content-Type or Content- Length)
  3. The client used IPv6 instead of IPv4
  4. The socket buffer size is too small

A published solution is not available for this question yet.

Question 4 MCQ · 1.0 marks

The server successfully receives and prints the HTTP request, but the browser shows “This site can’t be reached” or keeps loading. What is the most likely reason?
  1. The server did not call bind()
  2. The server did not send an HTTP response back to the client
  3. The browser used HTTPS instead of HTTP
  4. The request buffer size was too small

A published solution is not available for this question yet.

Question 5 MCQ · 1.0 marks

The server crashes while handling incoming data. The error occurs at: [[IMAGE:08f74d947e387466_3_2]] What is the most likely cause?
Source diagram or notation
  1. recv() returned -1 causing invalid indexing
  2. BUFFER SIZE is too large
  3. The server is not bound to the correct port
  4. The client is using HTTP/2 instead of HTTP/1.1

A published solution is not available for this question yet.

Question 6 MCQ · 1.0 marks

In your parser, you read: [[IMAGE:08f74d947e387466_3_3]] If data offset byte is 0x50, what is the TCP header length? (Assume upper nibble = 5.)
Source diagram or notation
  1. 8 bytes
  2. 16 bytes
  3. 20 bytes
  4. 32 bytes

A published solution is not available for this question yet.

Question 7 MCQ · 1.0 marks

You modify the server to accept a connection and immediately close it after reading a request: [[IMAGE:08f74d947e387466_4_4]] When you open http://127.0.0.1:8080/ in a browser, it shows an error like “Connection reset” or keeps retrying. On the server side, no errors are printed. What is the most likely reason?
Source diagram or notation
  1. The server does not send any HTTP response before closing the connection.
  2. The buffer size is too small to hold the HTTP request.
  3. The browser requires UDP instead of TCP for HTTP.
  4. The server must call write() before read().

A published solution is not available for this question yet.

Question 8 NAT · 1.0 marks

Assume a host in Mumbai wants to send a packet to a server in Delhi, approximately 1600 km away. If the signal travels at 3 × 10\(^{6}\) m/s, what is the one-way propagation delay in milliseconds? NOTE: Assume no processing or queuing delay(in ms).

    A published solution is not available for this question yet.

    Question 9 NAT · 1.0 marks

    If the one-way latency between two cities is measured to be 20 ms, the RTT (Round Trip Time) assuming symmetric paths and no processing delay is:

      A published solution is not available for this question yet.

      Question 10 NAT · 3.0 marks

      A transmitter sends packets of size 1000 bits at a rate of 5 Mbps from node X to node Y. The one- way delay is observed to vary between 20 ms (no queueing) and 120 ms (maximum queue), with an average of 60 ms. Assume queuing occurs only at one router along the path and there is no packet loss. What is the mean number of packets in the queue at the bottleneck link?

        A published solution is not available for this question yet.

        Question 11 NAT · 3.0 marks

        In a circuit-switched network, a source communicates with a destination through 6 intermediate switches. Each switch takes 3 ms to process a reservation request before forwarding it to the next node. The propagation delay between each pair of nodes (i.e., source/switch/destination) is 3 ms. What is the total time (in milliseconds) taken for the reservation request to reach the destination?

          A published solution is not available for this question yet.

          Question 12 SHORT_TEXT · 3.0 marks

          Consider the following 16-bit words (in hexadecimal) that are to be used in a UDP checksum calculation: [[IMAGE:08f74d947e387466_6_5]] After performing the checksum steps (summing all words, folding the overflow, and taking the one’s complement), what will be the final UDP checksum value? **NOTE:** Enter the exact answer without any extra space in the beginning or at the end.
          Source diagram or notation

            A published solution is not available for this question yet.

            Question 13 NAT · 3.0 marks

            A TCP connection uses the following identifiers: • Source IP = 192.168.1.11 • Destination IP = 10.1.0.5 • Source Port = 55000 • Destination Port = 80 Assuming that TCP port numbers range from 0 to 65535, but 0–1023 are the well-known (privileged) ports and are excluded, how many additional TCP connections can this host theoretically open to the same server (IP 10.0.0.5, port 80) using different source ports?

              A published solution is not available for this question yet.

              Question 14 NAT · 3.0 marks

              A 20 Mbps link has a propagation delay of 400 μs. The transmitter employs the Stop-and-Wait protocol. Assuming each frame is 200 bytes long, what is the maximum data rate possible? Note: Answer in Mbps

                A published solution is not available for this question yet.

                Question 15 NAT · 3.0 marks

                In a network with a bottleneck bandwidth of 20 Mbps and a round-trip time of 400 ms,what should be the minimum congestion window size (in bytes) to fully utilize the link?

                  A published solution is not available for this question yet.

                  Question 16 NAT · 3.0 marks

                  A TCP flow has a congestion window of 60 KB and an RTT of 600 ms. Calculate the average throughput in Mbps. Note: In two point precision

                    A published solution is not available for this question yet.

                    Question 17 NAT · 3.0 marks

                    In TCP BBR’s bottleneck bandwidth estimation, the ACK arrival rate measured over an epoch gives a delivery rate of 50 Mbps. If the minimum measured RTT (RTTmin) is 200 ms, what is BBR’s current estimate of the bottleneck bandwidth (in Mbps)?

                      A published solution is not available for this question yet.

                      Question 18 NAT · 3.0 marks

                      A TCP Reno connection detects congestion when CWND = 200 KB. After triple duplicate ACK, CWND is reduced to 3/4, and additive increase resumes with +1 KB per RTT. Compute the CWND after 3 RTTs post-loss.(in KB)

                        A published solution is not available for this question yet.

                        Question 19 NAT · 3.0 marks

                        An ISP manages a network block 172.16.0.0/11. It partitions and assigns a customer a smaller block 172.16.32.0/19. Determine how many total subnets the ISP could theoretically create from the original /11 block if it subdivides it completely into /19 subnets.

                          A published solution is not available for this question yet.

                          Question 20 NAT · 3.0 marks

                          How many distinct prefixes can a /11 block be divided into when it is subnetted up to /18 networks?

                            A published solution is not available for this question yet.

                            Question 21 NAT · 3.0 marks

                            An organization has 3,200 devices connected in a private network. Each NAT router can handle up to 80,000 simultaneous connections and can serve 290 devices comfortably. If they use NAT (one public IP per NAT router), how many public IP addresses are required?

                              A published solution is not available for this question yet.

                              Question 22 NAT · 4.0 marks

                              If you are designing sliding window protocol (assume selective repeat) of 8 Mbps which has one way delay of 1.55 seconds. Assuming each frame carries 2kB of data, what is the minimum number of bits you need for the sequence number?

                                A published solution is not available for this question yet.

                                Question 23 NAT · 2.0 marks

                                A BBR sender is currently transmitting at a rate of 10 Mbps. During a gain cycle, it applies a gain factor of 1.2 to probe for additional network capacity and then reduces its rate by a factor of 1/1.2 to conserve packets.What are the maximum sending rates of the BBR sender during this gain cycle? Note:Answer in Mbps

                                  A published solution is not available for this question yet.