Reference Guide

596 | Quality of Service
www.dell.com | support.dell.com
Figure 30-17. Honoring the DSCP Value on Incoming Voice Data
Honor the incoming dot1p value
On the C-Series, if you know traffic originating from the phone is tagged with a dot1p value of 5, you
might make the associated queue a strict priority queue, as shown in Figure 30-18; on the C-Series, FTOS
maps dot1p priority 5 to queue 2.
Figure 30-18. Honoring the Dot1P Value on Incoming Voice Traffic
Classifying VOIP traffic and applying QoS policies
Avoid congestion and give precedence to voice and signaling traffic by classifying traffic based on subnet
and using strict priority and bandwidth weights on egress, as outlined in the steps below.
Figure 30-19 depicts the topology and shows the configuration for a C-Series. The steps are the same on an
S-Series. Figure 30-20 on page 598 is a screenshot showing some of the steps and the resulting
running-config.
FTOS#sh run policy-map-input
!
policy-map-input HonorDSCP
trust diffserv
FTOS#sh run int gigabitethernet 6/11
!
interface GigabitEthernet 6/11
description "IP Phone X"
no ip address
portmode hybrid
switchport
service-policy input HonorDSCP
power inline auto
no shutdown
FTOS#sh run | grep strict-priority
strict-priority unicast 2
FTOS#sh run int gi 6/10
!
interface GigabitEthernet 6/10
description "IP Phone X"
no ip address
portmode hybrid
switchport
service-class dynamic dot1p
power inline auto
no shutdown
FTOS#sh run | grep strict-priority
strict-priority unicast 2