300-415 Question 293
Single answerAn enterprise deploying Cisco SD-WAN has a critical application that is sensitive to packet loss due to network congestion. They want to ensure optimal performance of this application by implementing Forward Error Correction (FEC). Which statement best describes the role of FEC in this scenario?
- A
FEC replicates application packets across multiple WAN links to ensure redundancy.
- B
FEC adds redundant information to the data stream, enabling packet loss recovery without retransmissions.
- C
FEC increases the packet size to prioritize the application traffic over other traffic types.
- D
FEC dynamically adjusts link bandwidth to reduce packet loss in real-time.
Show answer and explanation
Correct answer: B
Explanation
Forward Error Correction (FEC) is a mechanism used in Cisco SD-WAN to mitigate the impact of packet loss on critical applications. By adding redundant information to the data stream, it enables the reconstruction of lost packets at the receiver, avoiding the need for retransmissions. This ensures consistent application performance, especially for latency-sensitive applications, even in lossy network conditions.
- A. Incorrect.
FEC does not replicate packets across multiple WAN links. This describes a feature like path redundancy or load sharing, not FEC.
- B. Correct.
Correct. FEC introduces redundant data to the stream, enabling the receiver to reconstruct lost packets without requesting retransmissions, which is critical for latency-sensitive applications.
- C. Incorrect.
FEC does not increase the packet size to prioritize traffic. Traffic prioritization is achieved using QoS policies, not FEC.
- D. Incorrect.
FEC does not dynamically adjust link bandwidth. It is a mechanism to recover lost packets using redundant data, not a bandwidth management tool.