GATE CS 2026 Set 1 — Question 44
Go beyond PYQs with Success TrackerAI-powered personalised practice and doubt support. Unlimited practice on eligible plans; AI usage limits apply.MCQ+2 / -0.67HardTCP Congestion ControlTransport LayerComputer Networks
Computer Networks → Transport Layer → TCP Congestion Control
Last updated
Question
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 segment is lost. Let denote the time (in milliseconds) at which the transmission of segment number 2000 starts.Which one of the following options is correct?
Correct answer
(B) 10 ≤ t < 11
Solution
In TCP slow start, the congestion window (cwnd) starts at 1 MSS and doubles every Round Trip Time (RTT) as long as acknowledgments are received and cwnd < ssthresh.Given:
Let's find the round where the total segments sent reaches or exceeds 2000.Total sent after Round is .
Thus, the transmission of segment 2000 starts at a time such that .
- RTT = 1 ms
- ssthresh = 10000
- No losses
- Round 1 ( to ): cwnd = 1. Segments sent: 1. Total sent = 1.
- Round 2 ( to ): cwnd = 2. Segments sent: 2, 3. Total sent = .
- Round 3 ( to ): cwnd = 4. Segments sent: 4 to 7. Total sent = .
- ...
- Round ( to ): cwnd = . Total sent by end of round = .
Let's find the round where the total segments sent reaches or exceeds 2000.Total sent after Round is .
- For ( to ): Total sent = .
- For ( to ): Total sent = .
Thus, the transmission of segment 2000 starts at a time such that .
Continue learning with Success Tracker
A step still unclear? Work through it with support
Use Success Tracker to ask about the reasoning, then try another GATE CS question to check your understanding.
AI-powered practice· Unlimited practice on eligible plans
- PYQs with solutions
- Attempt available previous-year questions, then compare your reasoning with the worked solution. Coverage varies by stream.
- Practice that adapts
- Choose a topic, work on weaker areas and bookmark questions to revisit. Your attempts feed your progress tracking.
- AI doubt support
- Ask follow-up questions about a step or concept while practising, instead of stopping at the final answer.
Unlimited practice is available on eligible plans. Free practice and AI usage have limits; check the current plan allowances before choosing.
This page stays readable without an account. AI responses can be wrong; check them against the solution and source material.
More questions on Transport Layer
2026 Set 1 Q18With respect to a TCP connection between a client and a server, which one of the following…2026 Set 1 Q19Which of the following statements is/are true with respect to the interaction of a web browser with…2026 Set 2 Q21Consider a file of size 4 million bytes being transferred between two hosts connected via a path…2026 Set 2 Q22Which one of the following protocols may need to broadcast some of its messages?2026 Set 2 Q33If an IP network uses a subnet mask of 255.255.240.0, the maximum number of IP addresses that can…