📝 RSVP Resource Reservation Protocol (24 MCQs)

📖 From Data Communication and Networks • 30. Quality of Service • 24 questions available

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What is RSVP Resource Reservation Protocol?

The Resource Reservation Protocol is the signaling standard used in IntServ to communicate flow specifications and reservation requests between hosts and routers, establishing and maintaining the state necessary to provide per-flow QoS guarantees across the network.

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📝 All RSVP Resource Reservation Protocol MCQs

Q1. What does RSVP stand for?

A.Resource Reservation Protocol ✅

B.Remote System Validation Procedure

C.Routing Service Verification Process

D.Real-time Stream Video Protocol

💡 Difficulty: easy | ✅ Correct: A

📖 Explanation: RSVP is an acronym for Resource Reservation Protocol. It is a network protocol designed to reserve resources such as bandwidth for data flows, especially in integrated services networks.

Q2. At which layer of the OSI model is RSVP primarily implemented?

A.Network

B.Transport ✅

C.Application

D.Data Link

💡 Difficulty: easy | ✅ Correct: B

📖 Explanation: RSVP operates at the Transport layer of the OSI model. Although it works closely with the IP layer, its functions of signaling and resource reservation are defined as a transport‑layer service.

Q3. If a sender issues an RSVP PATH message but an intermediate router cannot satisfy the requested bandwidth, what is the most likely outcome?

A.The router discards the PATH message

B.The router forwards the PATH but ignores the reservation request

C.The router sends a RESVERR message back toward the sender ✅

D.The router modifies the PATH to request a lower bandwidth

💡 Difficulty: easy | ✅ Correct: C

📖 Explanation: When a router cannot meet the bandwidth specified in the PATH, it generates a RESVERR (reservation error) message that travels upstream, informing the sender that the reservation cannot be fulfilled.

Q4. When a receiver sends a RESV message downstream, how does an upstream router react if the downstream link later becomes congested?

A.It immediately drops the RESV message

B.It increases the reserved bandwidth to compensate

C.It forwards the RESV unchanged regardless of congestion

D.It may downgrade the reservation and send a RESVERR upstream ✅

💡 Difficulty: medium | ✅ Correct: D

📖 Explanation: If congestion appears after a reservation is made, the upstream router must reassess the reservation. It can downgrade the reserved bandwidth and issue a RESVERR to inform the receiver that the original reservation cannot be maintained.

Q5. Consider two flows sharing a link of 20 Mbps. Flow A requests 12 Mbps and Flow B requests 10 Mbps via RSVP. What will happen?

A.Both flows receive their full requests

B.Flow A receives 12 Mbps, Flow B receives 8 Mbps ✅

C.Both flows are reduced proportionally to fit the link capacity

D.RSVP rejects both reservations

💡 Difficulty: hard | ✅ Correct: B

📖 Explanation: The total requested bandwidth (22 Mbps) exceeds the link capacity (20 Mbps). RSVP will honor the first reservation (12 Mbps) and allocate the remaining capacity (8 Mbps) to the second flow, resulting in a shortfall for Flow B.

Q6. If a downstream router advertises a lower maximum bandwidth than previously reserved, how should an upstream router adjust its reservation state?

A.Ignore the advertisement and keep the original reservation ✅

B.Immediately cancel the reservation and notify the sender

C.Reduce the reservation to the advertised maximum and send a RESVERR if needed

D.Increase the reservation to compensate for the lower downstream value

💡 Difficulty: medium | ✅ Correct: A

📖 Explanation: RSVP routers maintain consistency by adjusting reservations to the most restrictive downstream advertisement. However, they do not ignore the change; they reduce the reservation to the new maximum and may generate a RESVERR if the reduction violates existing commitments.

Q7. A sender requests a 5 Mbps reservation, but the first-hop router can only provide 3 Mbps. Which RSVP message is generated?

A.PATH with modified bandwidth

B.RESV with increased bandwidth

C.RESVERR indicating insufficient resources

D.No message is generated; the flow is dropped ✅

💡 Difficulty: easy | ✅ Correct: D

📖 Explanation: When a router cannot satisfy the requested bandwidth, it generates a RESVERR message to inform the sender that the reservation cannot be fulfilled, prompting the sender to adjust its request or terminate the flow.

Q8. Which of the following best characterizes the analytical difference between RSVP and DiffServ regarding QoS control?

A.RSVP provides per‑flow state, DiffServ uses aggregate classes ✅

B.Both RSVP and DiffServ rely on static routing tables

C.RSVP uses only best‑effort delivery, DiffServ guarantees strict priority

D.DiffServ requires end‑to‑end signaling, RSVP does not

💡 Difficulty: easy | ✅ Correct: A

📖 Explanation: RSVP maintains per‑flow state and signals individual reservations, whereas DiffServ classifies traffic into aggregates and applies treatment based on class, eliminating the need for per‑flow signaling.

Q9. In a network where RSVP is deployed alongside MPLS, what logical effect does RSVP have on label‑switched paths?

A.RSVP replaces MPLS labels with its own identifiers

B.RSVP can be used to reserve bandwidth for an LSP, ensuring QoS for the path ✅

C.RSVP disables MPLS forwarding for reserved flows

D.RSVP does not interact with MPLS at all

💡 Difficulty: medium | ✅ Correct: B

📖 Explanation: RSVP can be used in conjunction with MPLS to reserve bandwidth for a label‑switched path, guaranteeing the required QoS for traffic that traverses the LSP while MPLS continues handling the forwarding.

Q10. A network engineer observes that RSVP RESV messages are being dropped at a router due to a full queue. Which logical inference is most appropriate?

A.The router’s CPU is overloaded

B.The network lacks sufficient buffer space for reservation signaling ✅

C.RSVP is incompatible with the router’s hardware

D.The sender’s PATH messages are malformed

💡 Difficulty: medium | ✅ Correct: B

📖 Explanation: If RESV messages are discarded because the queue is full, it indicates insufficient buffer resources for RSVP signaling traffic, suggesting the need for queue management or increased buffer allocation.

Q11. How does RSVP handle reservation refresh intervals to maintain state consistency?

A.It sends a RESV only once and never refreshes

B.It periodically retransmits RESV messages before the refresh timer expires

C.It relies on TCP acknowledgments to confirm reservations ✅

D.It uses a separate control channel that does not require timers

💡 Difficulty: hard | ✅ Correct: C

📖 Explanation: RSVP uses periodic refresh of RESV messages; if a reservation is not refreshed before the timer expires, the state is torn down. This mechanism ensures that stale reservations are removed automatically.

Q12. When comparing RSVP with Integrated Services (IntServ), which statement accurately reflects their relationship?

A.RSVP is the signaling component of IntServ ✅

B.IntServ is a subset of RSVP functionality

C.RSVP replaces IntServ in modern networks

D.IntServ and RSVP are unrelated protocols

💡 Difficulty: medium | ✅ Correct: A

📖 Explanation: RSVP provides the signaling mechanism for the Integrated Services architecture, allowing applications to request specific QoS parameters that IntServ then attempts to enforce across the network.

Q13. In a scenario where multiple receivers join a multicast group using RSVP, what analytical outcome occurs regarding resource allocation?

A.Only the first receiver’s reservation is honored

B.Each receiver’s reservation is treated independently, potentially leading to over‑reservation ✅

C.RSVP aggregates all receiver requests into a single reservation

D.RSVP denies all reservations to avoid complexity

💡 Difficulty: medium | ✅ Correct: B

📖 Explanation: RSVP treats each receiver’s reservation independently. When many receivers request bandwidth, the cumulative reservations may exceed available resources, causing the need for admission control or reservation reduction.

Q14. If an RSVP-enabled router implements the 'soft state' principle, what conceptual effect does this have on network robustness?

A.State is permanently stored, preventing changes

B.State information is automatically discarded after a timeout unless refreshed

C.State is encrypted to protect against tampering ✅

D.State is shared with all neighboring routers instantly

💡 Difficulty: hard | ✅ Correct: C

📖 Explanation: The soft‑state principle means that reservation information is periodically refreshed; if updates stop, the state expires. This design improves robustness by allowing the network to recover from failures without manual intervention.

Q15. A sender wishes to reserve a path with a maximum latency of 50 ms. Which RSVP object should it include to express this requirement?

A.Bandwidth object

B.Priority object

C.Delay‑bound object ✅

D.Fragmentation object

💡 Difficulty: medium | ✅ Correct: C

📖 Explanation: The Delay‑bound object in RSVP allows a sender to specify a maximum end‑to‑end latency, such as 50 ms, enabling routers to enforce the timing constraint along the reserved path.

Q16. When a network administrator disables RSVP on a core router, what is the most likely conceptual consequence for existing reservations?

A.All reservations become permanent and unchanged

B.All existing reservations are immediately torn down ✅

C.Reservations continue unaffected until the next refresh interval

D.RSVP traffic is rerouted through a backup router

💡 Difficulty: hard | ✅ Correct: B

📖 Explanation: Disabling RSVP on a router causes it to stop processing RSVP messages, leading to the immediate removal of any reservations that depend on that router, as the soft‑state information can no longer be refreshed.

Q17. How does RSVP support hierarchical QoS models in large networks?

A.By aggregating multiple reservations into a single class‑wide reservation

B.By allowing each router to independently decide its own QoS policy

C.By providing per‑flow signaling that can be mapped onto aggregate classes at higher layers ✅

D.RSVP does not support hierarchical QoS at all

💡 Difficulty: easy | ✅ Correct: C

📖 Explanation: RSVP’s per‑flow reservations can be mapped onto higher‑level aggregate classes (e.g., DiffServ PHBs), enabling hierarchical QoS where detailed flow information is abstracted into broader service classes.

Q18. Which analytical factor most directly influences the scalability limit of RSVP in a wide‑area network?

A.The size of the routing tables

B.The number of simultaneous reservation state entries maintained by routers ✅

C.The length of the IP address prefix

D.The frequency of ARP broadcasts

💡 Difficulty: medium | ✅ Correct: B

📖 Explanation: RSVP scalability is primarily constrained by the amount of per‑flow state each router must keep. As the number of concurrent reservations grows, memory and processing requirements increase, limiting scalability.

Q19. In a scenario where a flow’s reserved bandwidth is 8 Mbps but the actual traffic peaks at 12 Mbps, what conceptual mechanism ensures the excess traffic does not affect other flows?

A.RSVP drops the excess packets automatically

B.RSVP uses traffic shaping at the sender to limit the rate

C.RSVP relies on underlying queueing disciplines to enforce the reservation ✅

D.RSVP expands the reservation dynamically to accommodate the burst

💡 Difficulty: hard | ✅ Correct: C

📖 Explanation: RSVP itself does not shape traffic; it relies on the router’s queueing and scheduling mechanisms (e.g., Weighted Fair Queuing) to enforce the reserved bandwidth, ensuring that traffic exceeding the reservation is queued or dropped without impacting other flows.

Q20. If a receiver sends a RESV message with a lower priority than previously advertised, what logical effect does this have on the reservation?

A.The reservation priority is upgraded automatically

B.The reservation is downgraded, possibly causing pre‑emption of higher‑priority traffic ✅

C.The reservation remains unchanged regardless of the new priority

D.RSVP rejects the RESV due to priority mismatch

💡 Difficulty: medium | ✅ Correct: B

📖 Explanation: When a RESV with a lower priority is received, the reservation is adjusted to the new, lower priority level. This may result in pre‑empting higher‑priority traffic if resources become scarce, reflecting RSVP’s ability to renegotiate QoS parameters.

Q21. When integrating RSVP with IPv6, which conceptual change is required compared to IPv4?

A.RSVP must be replaced by a completely different protocol

B.RSVP messages are encapsulated in IPv6 Extension Headers ✅

C.RSVP uses a new set of objects exclusive to IPv6

D.No changes are needed; RSVP works identically over IPv6

💡 Difficulty: hard | ✅ Correct: B

📖 Explanation: RSVP for IPv6 (RSVPv2) utilizes IPv6 Extension Headers to carry its messages, allowing RSVP signaling to coexist with IPv6’s larger address space while preserving the protocol’s core functionality.

Q22. A network with RSVP-enabled routers experiences frequent reservation failures during peak hours. Which analytical improvement is most likely to reduce these failures?

A.Increasing the MTU size on all links

B.Deploying larger buffers and enabling admission control policies ✅

C.Disabling RSVP and switching to best‑effort routing

D.Reducing the number of routers in the path

💡 Difficulty: easy | ✅ Correct: B

📖 Explanation: Providing larger buffers and implementing admission control helps ensure that sufficient resources are available before admitting new reservations, thereby decreasing the likelihood of reservation failures during high‑traffic periods.

Q23. How does RSVP handle reservation persistence when a link fails and a new alternate path is computed by the routing protocol?

A.Reservations are automatically transferred to the new path without any signaling

B.RSVP discards the old reservations and requires the application to re‑initiate the reservation process

C.RSVP attempts to re‑establish the reservation along the new path using refreshed PATH and RESV messages ✅

D.The alternate path is ignored until the original link is restored

💡 Difficulty: medium | ✅ Correct: C

📖 Explanation: When a link fails, RSVP’s soft‑state timers expire, prompting the sender to send new PATH messages along the new route. The receiver then issues RESV messages, allowing the reservation to be re‑established on the alternate path.

Q24. In a multi‑domain environment, what conceptual challenge does RSVP face regarding inter‑domain QoS guarantees?

A.RSVP cannot operate across different IP versions

B.Different administrative domains may have incompatible reservation policies, making end‑to‑end QoS enforcement difficult ✅

C.RSVP automatically enforces uniform QoS across all domains without configuration

D.RSVP requires each domain to use the same routing protocol

💡 Difficulty: hard | ✅ Correct: B

📖 Explanation: Inter‑domain QoS is challenging because each domain may enforce its own policies, resource limits, and reservation mechanisms. RSVP must negotiate across these boundaries, and inconsistencies can prevent a seamless end‑to‑end QoS guarantee.

🔗 Related Topics (MCQs)

📝 Data flow characteristics in QoS MCQs 📝 QoS definitions in computer networks MCQs 📝 Application sensitivity to QoS parameters MCQs 📝 Flow classes in quality of service MCQs 📝 Flow control techniques for QoS MCQs

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