300-415 Question 283
Single answerA network administrator has deployed Cisco SD-WAN to optimize application performance across a WAN. The organization is experiencing high latency and packet loss over long-distance links, negatively impacting TCP-based applications such as file transfers and database replication. Which feature of Cisco SD-WAN can be configured to specifically address these issues and improve TCP performance?
- A
TCP optimization using TCP BBR congestion control
- B
Forward Error Correction (FEC)
- C
Application-Aware Routing
- D
Data Redundancy Elimination (DRE)
Show answer and explanation
Correct answer: B
Explanation
The correct answer is Forward Error Correction (FEC). FEC ensures that TCP-based applications can tolerate packet loss by adding redundancy at the SD-WAN layer, which allows lost packets to be reconstructed at the receiving end without requiring retransmissions. This is particularly useful in high-latency or lossy network environments, where retransmissions can further degrade performance.
- A. Incorrect.
TCP BBR congestion control is not a feature of Cisco SD-WAN. It is a Google-developed congestion control algorithm that operates in the TCP stack of endpoints, not in Cisco SD-WAN devices.
- B. Correct.
Forward Error Correction (FEC) is a feature of Cisco SD-WAN that helps mitigate packet loss by sending redundant data packets, allowing the receiver to reconstruct lost packets without requiring retransmissions. This improves TCP performance over lossy links.
- C. Incorrect.
Application-Aware Routing helps route traffic based on real-time network conditions and application requirements, but it does not directly optimize TCP performance in high-latency or lossy environments.
- D. Incorrect.
Data Redundancy Elimination (DRE) is used to reduce bandwidth consumption by eliminating duplicate data but does not directly address TCP performance issues caused by packet loss or high latency.