300-415 Question 284
Select 3An enterprise has implemented Cisco SD-WAN and wants to optimize bandwidth usage by ensuring redundant data is not transmitted across the WAN links. The team decides to enable Data Redundancy Elimination (DRE) on their SD-WAN fabric. Which of the following statements about DRE in Cisco SD-WAN are true?
- A
DRE works by identifying and eliminating duplicate data patterns at the packet level.
- B
DRE operates on TCP sessions and requires the application of IPsec encryption to function.
- C
DRE requires local data caches on the SD-WAN edge devices to store redundant data patterns.
- D
DRE is primarily a feature designed to reduce latency for real-time applications.
- E
DRE can help reduce WAN bandwidth usage by avoiding the retransmission of previously sent data.
Show answer and explanation
Correct answers: A, C, E
Explanation
Data Redundancy Elimination (DRE) in Cisco SD-WAN is a bandwidth optimization feature that identifies and eliminates duplicate data patterns to reduce the amount of data transmitted over WAN links. It relies on local data caches on SD-WAN edge devices to store redundant data patterns and helps conserve bandwidth by avoiding the retransmission of previously sent data. DRE operates at the packet level and is protocol-independent, making it a critical feature for optimizing WAN efficiency.
- A. Correct.
Correct: DRE operates by identifying duplicate data patterns and eliminating them at the packet level, thus conserving bandwidth.
- B. Incorrect.
Incorrect: DRE operates independently of TCP sessions or IPsec encryption. While encryption can be used with SD-WAN, it is not a prerequisite for DRE.
- C. Correct.
Correct: DRE uses local data caches on edge devices to store redundant data patterns, enabling it to recognize and eliminate repeated transmission.
- D. Incorrect.
Incorrect: DRE focuses on bandwidth optimization by reducing redundant data transmission, not latency reduction for real-time applications.
- E. Correct.
Correct: By avoiding retransmission of previously sent data, DRE effectively reduces WAN bandwidth usage.