List of top Computer Networks Questions

Consider a network that uses Ethernet and IPv4. Assume that IPv4 headers do not use any options field. Each Ethernet frame can carry a maximum of 1500 bytes in its data field. A UDP segment is transmitted. The payload (data) in the UDP segment is 7488 bytes. Which ONE of the following choices has the CORRECT total number of fragments transmitted and the size of the last fragment including IPv4 header?

Suppose a message of size 15000 bytes is transmitted from a source to a destination using IPv4 protocol via two routers as shown in the figure. Each router has a defined maximum transmission unit (MTU) as shown in the figure, including IP header. The number of fragments that will be delivered to the destination is ___________. (Answer in integer)

Consider the 3-way handshaking protocol for TCP connection establishment. Let the three packets exchanged during the connection establishment be denoted as P1, P2, and P3, in order. Which of the following option(s) is/are TRUE with respect to TCP header flags that are set in the packets?

Consider a context-free grammar $G$ with the following 3 rules: \[ S \to aS, \quad S \to aSbS, \quad S \to c \] Let $w \in L(G)$. Let $n_a(w), n_b(w), n_c(w)$ denote the number of times $a, b, c$ occur in $w$, respectively. Which of the following statements is/are TRUE?

Consider an Ethernet segment with a transmission speed of $10^8 \, \text{bits/sec}$ and a maximum segment length of $500 \, \text{meters}$. If the speed of propagation of the signal in the medium is $2 \times 10^8 \, \text{meters/sec}$, then the minimum frame size (in bits) required for collision detection is ............

Consider a TCP connection operating at a point of time with the congestion window of size $12 \, \text{MSS}$ (Maximum Segment Size), when a timeout occurs due to packet loss. Assuming that all the segments transmitted in the next two RTTs (Round Trip Time) are acknowledged correctly, the congestion window size (in MSS) during the third RTT will be ............

A functional dependency $F: X \to Y$ is termed as a useful functional dependency if and only if it satisfies all the following three conditions: $X$ is not the empty set. $Y$ is not the empty set. Intersection of $X$ and $Y$ is the empty set. For a relation $R$ with 4 attributes, the total number of possible useful functional dependencies is ............

Let $G$ be an undirected connected graph in which every edge has a positive integer weight. Suppose that every spanning tree in $G$ has even weight. Which of the following statements is/are TRUE for every such graph $G$?

Let $x$ and $y$ be random variables, not necessarily independent, that take real values in the interval $[0, 1]$. Let $z = xy$ and let the mean values of $x, y, z$ be $\bar{x}, \bar{y}, \bar{z}$, respectively. Which one of the following statements is TRUE?

Let $S1$ and $S2$ be two stacks. $S1$ has a capacity of 4 elements, and $S2$ has a capacity of 2 elements. $S1$ already has 4 elements: 100, 200, 300, and 400, whereas $S2$ is empty, as shown below. \begin{center} \includegraphics[width=8cm]{48.png} \end{center} Only the following three operations are available:
\texttt{PushToS2:} Pop the top element from $S1$ and push it on $S2$.
\texttt{PushToS1:} Pop the top element from $S2$ and push it on $S1$.
\texttt{GenerateOutput:} Pop the top element from $S1$ and output it to the user. Note: - The pop operation is not allowed on an empty stack.
- The push operation is not allowed on a full stack. Which of the following output sequences can be generated by using the above operations?

Which of the following is/are EQUAL to 224 in radix-5 (i.e., base-5) notation?

You are given a set $V$ of distinct integers. A binary search tree $T$ is created by inserting all elements of $V$ one by one, starting with an empty tree. The tree $T$ follows the convention that, at each node, all values stored in the left subtree of the node are smaller than the value stored at the node. You are not aware of the sequence in which these values were inserted into $T$, and you do not have access to $T$. Which one of the following statements is TRUE?

Which of the following file organizations is/are I/O efficient for the scan operation in DBMS?}

In the context of owner and weak entity sets in the ER (Entity-Relationship) data model, which one of the following statements is TRUE?

What is the full form of IP in the Internet communication system ?

Identify the protocol name(s) used in computer network from the following.
(A) FTP
(B) HTML
(C) HTTP
(D) Telnet
(E) Modem
Choose the correct answer from the options given below:

What is the maximum number of subnetworks for the default mask 255.255.0.0 and subnet mask 255.255.224.0?

The full form of MQTT is

Which of the following is not transition strategy from IPv4 to IPv6?

Consider a computer network using the distance vector routing algorithm in its network layer. The partial topology of the network is as shown.
The objective is to find the shortest-cost path from the router $R$ to routers $P$ and $Q$. Assume that $R$ does not initially know the shortest routes to $P$ and $Q$. Assume that $R$ has three neighbouring routers denoted as $X$, $Y$, and $Z$. During one iteration, $R$ measures its distance to its neighbours $X, Y, Z$ as $3, 2,$ and $5$, respectively. Router $R$ gets routing vectors from its neighbours that indicate: - Distance to router $P$ from $X, Y, Z$ are $7, 6,$ and $5$, respectively. - Distance to router $Q$ from $X, Y, Z$ are $4, 6,$ and $8$, respectively.

Which of the following statement(s) is/are correct with respect to the new routing table of $R$, after update during this iteration?

Consider a network using the pure ALOHA medium access control protocol. Each frame is of length 1000 bits and the channel rate is 1 Mbps. The aggregate transmission attempt rate is 1000 frames per second. The throughput of the network (rounded to the nearest integer) is $\underline{\hspace{2cm}}$.

Consider the cyclic redundancy check (CRC) based error detecting scheme having the generator polynomial $X^3 + X + 1$. Suppose the message $m_4 m_3 m_2 m_1 m_0 = 11000$ is to be transmitted. Check bits $c_2 c_1 c_0$ are appended at the end of the message by the transmitter using the above CRC scheme. The transmitted bit string is denoted by $m_4 m_3 m_2 m_1 m_0 c_2 c_1 c_0$. The value of the checkbit sequence $c_2 c_1 c_0$ is

Consider the three-way handshake mechanism followed during TCP connection establishment between hosts $P$ and $Q$. Let $X$ and $Y$ be two random 32-bit starting sequence numbers chosen by $P$ and $Q$ respectively. Suppose $P$ sends a TCP connection request message to $Q$ with a TCP segment having SYN bit = 1, SEQ number = $X$, and ACK bit = 0. Suppose $Q$ accepts the connection request. Which one of the following choices represents the information present in the TCP segment header that is sent by $Q$ to $P$?

The TCP connection establishment process involves a 3-way handshake. Which of the following steps correctly represents the 3-way handshake?

Consider an ethernet segment whose transmission is $10^8$ bits per second. Maximum segment length $500\ m$, speed of the provocation media velocity is $2 × 10^8$ meter per second. What is the minimum frame size in bits ?