300-415 Question 295
Select 3An enterprise is experiencing packet loss on a critical voice application running over its Cisco SD-WAN network. The IT administrator decides to enable Forward Error Correction (FEC) to mitigate the packet loss. Which of the following statements accurately describe how FEC operates in this scenario?
- A
FEC adds redundant data packets to the transmission to allow the receiver to reconstruct lost packets.
- B
FEC requires re-transmission of lost packets to ensure data integrity in real-time applications.
- C
FEC operates independently of TCP or UDP protocols, making it suitable for real-time traffic like voice and video.
- D
FEC increases bandwidth usage due to the addition of redundant packets.
- E
FEC only operates on encrypted data streams within the Cisco SD-WAN fabric.
Show answer and explanation
Correct answers: A, C, D
Explanation
Forward Error Correction (FEC) is a mechanism used within Cisco SD-WAN to address packet loss by adding redundant data to the transmission. This allows the receiver to reconstruct lost packets without requiring retransmission, making it highly suitable for real-time applications like voice and video. However, this comes at the cost of increased bandwidth usage due to the additional redundant packets. FEC operates independently of transport protocols and is not limited to encrypted data streams.
- A. Correct.
Correct. FEC adds redundant data packets, enabling the receiver to recover lost packets without requiring retransmission, which is crucial for real-time applications like voice.
- B. Incorrect.
Incorrect. FEC avoids retransmission by adding redundancy, making it ideal for real-time applications where retransmission is not feasible.
- C. Correct.
Correct. FEC is protocol-independent and is particularly effective for real-time traffic such as voice and video, where packet loss can severely degrade quality.
- D. Correct.
Correct. FEC increases bandwidth usage because additional redundant packets are sent along with the original data.
- E. Incorrect.
Incorrect. FEC operates on all traffic types within the Cisco SD-WAN fabric, whether encrypted or not. It is not limited to encrypted streams.