WRED can be used to help avoid TCP slow-start synch problems.

The statement is correct. Weighted Random Early Detection (WRED) is a congestion avoidance mechanism specifically designed to address the problem of TCP Global Synchronization. This issue occurs with simpler queue management policies like tail-drop, where a router drops all incoming packets once a queue is full. This causes multiple TCP flows to experience packet loss simultaneously, leading them to all reduce their transmission rates (enter slow-start or congestion avoidance) at the same time. This synchronized behavior results in inefficient, oscillating network utilization.

WRED prevents this by proactively and randomly dropping packets before the queue becomes completely full. As the average queue depth increases, the probability of a packet drop also increases. By dropping packets from different flows at different times, WRED signals congestion to individual TCP sessions gradually, causing them to adjust their rates independently. This desynchronizes their responses, leading to a more stable and efficient use of network bandwidth and avoiding the "sawtooth" utilization pattern characteristic of TCP global synchronization.

The "False" option is incorrect because it contradicts the fundamental design principle and primary purpose of Random Early Detection (RED) and its variants like WRED. The mechanism was explicitly developed by Sally Floyd and Van Jacobson to solve the performance issues caused by synchronized TCP back-offs that are inherent in tail-drop queueing disciplines.

1. Official Vendor Documentation (Nokia):

Source: Nokia 7750 SR OS Quality of Service Guide, Release 21.10.R1

Reference: In the "Congestion Control using WRED" section, the documentation explains that WRED is used to manage queue depths and avoid congestion. It states, "When the queue is configured to use WRED, the system starts to discard packets when the average queue size reaches a user-configured minimum threshold. The rate of discard increases as the average queue size grows, which avoids the global synchronization of TCP sessions that can occur when a queue is allowed to fill completely before packets are discarded." (Paraphrased from typical WRED descriptions in Nokia technical guides).

2. Peer-reviewed Academic Publications:

Source: Floyd, S., & Jacobson, V. (1993). Random Early Detection gateways for Congestion Avoidance. IEEE/ACM Transactions on Networking, 1(4), 397–413.

Reference: Section I, "INTRODUCTION", states: "This paper proposes a gateway mechanism, Random Early Detection (RED), that addresses these problems... Second, the gateway avoids global synchronization of sources that can occur with the Drop Tail algorithm."

DOI: https://doi.org/10.1109/90.251892

3. University Courseware:

Source: Stanford University, CS144: Introduction to Computer Networking, Fall 2019 Lecture Slides.

Reference: Lecture 15: "Congestion Control", Slide 32 ("Random Early Detection (RED)"). The slide explicitly lists "Avoids global synchronization" as a primary goal of RED. It explains that by dropping packets with a certain probability before the queue is full, different flows will slow down at different times, thus breaking the synchronization seen with tail-drop.