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?
6406536961658.
The server did not call bind()
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The server did not send an HTTP response back to the client
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The browser used HTTPS instead of HTTP
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The request buffer size was too small
A published solution is not available for this question yet.
You modify the server to accept a connection and immediately close it after reading a request:
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?
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The server does not send any HTTP response before closing the connection.
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The buffer size is too small to hold the HTTP request.
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The browser requires UDP instead of TCP for HTTP.
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The server must call write() before read().
A published solution is not available for this question yet.
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.
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.
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.
Consider the following 16-bit words (in hexadecimal) that are to be used in a UDP checksum
calculation:
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.
A published solution is not available for this question yet.
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.
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.
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.
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.
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.
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.
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.
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.
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.
