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Cisco AVVID Network Infrastructure Enterprise Quality of Service Design
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Chapter 1 Overview
Why is Quality of Service Required for AVVID?
Figure 1-1
Areas Where QoS is Needed
Loss
Loss (or packet loss) is a comparative measure of packets faithfully transmitted and received to the total
number that were transmitted. Loss is expressed as the percentage of packets that were dropped.
81099
M
WAN
Central campus
Remote branch
Si
Si
IP
IP
QoS - Campus Access
QoS - Campus Dist.
QoS - WAN
QoS - Branch
Establish Trust Boundary
Layer 2 (802.1p) to Layer 3
(DSCP) classification
Layer 3 (DSCP) to Layer 2
(802.1p) classification
Layer 2 or Layer 3
classification where
required-service policies
CoS/DSCP to queue entry
criteria
Multiple queues and queue
scheduling (priority or high)
Establish Trust Boundary-
Trust DSCP or CoS from
Access Layer
Layer 2 (802.1p) to Layer 3
(DSCP) classification
Layer 3 (DSCP) to Layer 2
(802.1p) classification
Layer 2 or Layer 3
classification where
required-service policies
CoS/DSCP to queue entry
criteria
Multiple queues and queue
scheduling (priority or high)
Map L3 DSCP to L2 CoS
via sevice policy out and
802.1q trunk
Layer 2 (802.1p) to Layer 3
(DSCP) classification
Layer 3 (DSCP) to Layer 2
(802.1p) classification
Layer 2 or Layer 3
classification where
required-service policies
CoS/DSCP to queue entry
criteria
Multiple queues and queue
scheduling (priority or high)
Low-latency queuing
Data traffic queue
provisioning
Link Fragmentation and
interleave
Traffic shaping
Admission control