Cisco Systems 3750E manual Default Standard QoS Configuration, Default Ingress Queue Configuration

Chapter 36 Configuring QoS

Configuring Standard QoS

Default Standard QoS Configuration

QoS is disabled. There is no concept of trusted or untrusted ports because the packets are not modified (the CoS, DSCP, and IP precedence values in the packet are not changed). Traffic is switched in pass-through mode (packets are switched without any rewrites and classified as best effort without any policing).

When QoS is enabled with the mls qos global configuration command and all other QoS settings are at their defaults, traffic is classified as best effort (the DSCP and CoS value is set to 0) without any policing. No policy maps are configured. The default port trust state on all ports is untrusted. The default ingress and egress queue settings are described in the “Default Ingress Queue Configuration” section on page 36-33and the “Default Egress Queue Configuration” section on page 36-34.

Default Ingress Queue Configuration

Table 36-6shows the default ingress queue configuration when QoS is enabled.

Table 36-6	Default Ingress Queue Configuration
Feature		Queue 1	Queue 2
Buffer allocation		90 percent	10 percent
Bandwidth allocation 1		4	4
Priority queue bandwidth 2		0	10
WTD drop threshold 1		100 percent	100 percent
WTD drop threshold 2		100 percent	100 percent

1.The bandwidth is equally shared between the queues. SRR sends packets in shared mode only.

2.Queue 2 is the priority queue. SRR services the priority queue for its configured share before servicing the other queue.

Table 36-7shows the default CoS input queue threshold map when QoS is enabled.

Table 36-7	Default CoS Input Queue Threshold Map
CoS Value		Queue ID–Threshold ID
0–4		1–1
5		2–1
6, 7		1–1

Table 36-8shows the default DSCP input queue threshold map when QoS is enabled.

Table 36-8	Default DSCP Input Queue Threshold Map
DSCP Value		Queue ID–Threshold ID
0–39		1–1
40–47		2–1
48–63		1–1

	Catalyst 3750-E and 3560-E Switch Software Configuration Guide
OL-9775-02		36-33