GATE CS Computer Networks questions

With respect to a TCP connection between a client and a server, which one of the following statements is true?

Which of the following statements is/are true with respect to the interaction of a web browser with a web server using HTTP $1.1$?

A TCP sender successfully establishes a connection with a TCP receiver and starts the transmission of segments. The TCP congestion control mechanism's slow-start threshold is set to $10000$ segments. Assume that the round-trip time is fixed at $1$ millisecond. Assume that the sender always has data to send, the segments are numbered from $1$, and no …

Consider the implementation of sliding window protocol over a lossless link, with a window size of $W$ frames, where each frame is of size $1000$ bits (including header). The bandwidth of the link is $100 \mathrm{kbps}\left(1 \mathrm{k}=10^{3}\right)$ and the one-way propagation delay is $100$ milliseconds. Assume that processing times at the sender …

An ISP having an address block $202.16.0.0/15$ assigns a block of $6000$ IP addresses to a client, using the classless internet domain routing (CIDR) super-netting approach. Which of the following address blocks can be assigned by the ISP?

Consider a file of size $4$ million bytes being transferred between two hosts connected via a path consisting of three consecutive links of bandwidth $2$ Mbps , $500$ kbps , and $1$ Mbps , respectively. All processing delays and propagation delays are negligible. Assume that there is no other background traffic over the path and no other additional …

Which one of the following protocols may need to broadcast some of its messages?

If an IP network uses a subnet mask of $255.255.240.0$, the maximum number of IP addresses that can be assigned to network interfaces is $\_\_\_\_$. (answer in integer)

Consider the transmission of data bits $110001011$ over a link that uses Cyclic Redundancy Check (CRC) code for error detection. If the generator bit pattern is given to be $1001$, which one of the following options shows the remainder bit pattern appended to the data bits before transmission?

Consider a new TCP connection between a sender and a receiver. The receiver advertised window is constant at $48$ KB, the maximum segment size (MSS) is $2$ KB, and the slow start threshold for TCP congestion control is $16$ KB. Assume that there are no timeouts or duplicate acknowledgements. The number of rounds of transmission required for the …

It is necessary to design a link-layer protocol between two hosts that are directly connected over a lossless link of length $3000$ kilometers. Assume that the link bandwidth is $10^{8}$ bits per second and that the propagation delay in the link is $5$ nanoseconds per meter. Every transmitted data byte is assigned a unique sequence number. Let $N$ be …

Identify the ONE CORRECT matching between the OSI layers and their corresponding functionalities as shown. …

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

A packet with the destination $\text{IP}$ address $145.36 .109 .70$ arrives at a router whose routing table is shown. Which interface will the packet be forwarded to? …

Suppose a $5$-bit message is transmitted from a source to a destination through a noisy channel. The probability that a bit of the message gets flipped during transmission is $0.01$. Flipping of each bit is independent of one another. The probability that the message is delivered error-free to the destination is ___________ (rounded off to three decimal …

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 following statements: Address Resolution Protocol (ARP) provides a mapping from an IP address to the corresponding hardware (link-layer) address. A single TCP segment from a sender $S$ to a receiver $R$ cannot carry both data from $S$ to $R$ and acknowledgement for a segment from $R$ to $S$ Which one of the following is CORRECT?

Consider the routing protocols given in List I and the names given in List II: …

​​​A machine receives an $IPv4$ datagram. The protocol field of the $IPv4$ header has the protocol number of a protocol $X$. Which ONE of the following is NOT a possible candidate for $X$?

​​​​​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 UDPO segment is $7488$ bytes. Which ONE of the following choices has the CORRECT total number of fragments …