300-415 Question 285
Select 3An enterprise is implementing Cisco SD-WAN to optimize WAN traffic and reduce bandwidth usage. The IT team wants to enable Data Redundancy Elimination (DRE) to improve efficiency across multiple branch sites. Which of the following considerations are accurate when implementing DRE in this environment?
- A
DRE reduces redundant data transmission by caching data patterns at both the sender and receiver.
- B
DRE can only operate effectively if the underlying transport protocol is TCP.
- C
DRE works at the application layer to identify and eliminate redundant traffic patterns.
- D
DRE is effective in environments where the same data is transmitted frequently between sites.
- E
Enabling DRE increases CPU and memory usage on SD-WAN edge devices.
Show answer and explanation
Correct answers: A, D, E
Explanation
Data Redundancy Elimination (DRE) is a feature in Cisco SD-WAN designed to reduce redundant data transmission across WAN links. It achieves this by caching data patterns at both ends of the communication, effectively transmitting only unique data. DRE is transport-agnostic and operates at the packet level, not the application layer. While it significantly optimizes bandwidth in repetitive traffic scenarios, it does require some trade-offs, such as increased CPU and memory usage on edge devices.
- A. Correct.
Correct. DRE uses caching mechanisms at both the sender and receiver to identify and eliminate redundant data patterns, reducing the need to retransmit the same data.
- B. Incorrect.
Incorrect. DRE operates at the packet level and is transport-agnostic, meaning it is not limited to TCP.
- C. Incorrect.
Incorrect. DRE works at the packet level, not the application layer, to identify redundant traffic patterns.
- D. Correct.
Correct. DRE is particularly useful in scenarios where the same data (e.g., files, videos) is sent frequently between sites, as it reduces duplicate transmissions.
- E. Correct.
Correct. Enabling DRE requires additional CPU and memory resources on SD-WAN edge devices to process and cache data patterns.