Sred; Sred Settings - D-Link DES-3528 User Manual

xStack DES-3528 Series Layer 2 Stackable Fast Ethernet Managed Switch User Manual
WRR
Click Apply to implement changes made.

SRED

Simple random early detection (sRED) is a simplified RED mechanism based on ASIC capability. Random Early
Detection (RED) is a congestion avoidance mechanism at the gateway in packet switched networks. RED gateways
keep the average queue size low while allowing occasional bursts of packets in the queue. The switch provides
support for sRED through active queue management by probabilistic dropping of incoming colored packets.
Active queue management is a class of algorithms that attempt to proactively drop or mark frames before congestion
becomes excessive. The goal is to detect the onset of persistent congestion and take proactive action so that TCP
sources contributing to the congestion back off gracefully, insuring good network utilization while minimizing frame
loss.
This proactive approach starts discarding specific colored packets before the packet buffer becomes full. If this queue
depth is less than the threshold, there is minimal (or no) congestion and the packet is enqueued. If congestion is
detected the packet is dropped or queued based on the DSCP.

SRED Settings

To view this window click QoS > SRED > SRED Settings
Use the weighted round-robin (WRR) algorithm to handle packets in an even distribution in
priority classes of service.
NOTE: The settings you assign to the queues, numbers 0-7, represent the IEEE
802.1p priority tag number. Do not confuse these settings with port numbers.
Figure 8- 8. SRED Settings window
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