3 Create a second DiffServ classifier named 'class_ef' and define a single match criterion to detect a
DiffServ code point (DSCP) of 'EF' (expedited forwarding). This handles incoming traffic that was
previously marked as expedited elsewhere in the network.
class-map match-all class_ef
match ip dscp ef
exit
4 Create a DiffServ policy for inbound traffic named 'pol_voip', then add the previously created classes
'class_ef' and 'class_voip' as instances within this policy.
This policy handles incoming packets already marked with a DSCP value of 'EF' (per 'class_ef'
definition), or marks UDP packets per the 'class_voip' definition) with a DSCP value of 'EF'. In each
case, the matching packets are assigned internally to use queue 5 of the egress port to which they
are forwarded.
policy-map pol_voip in
class class_ef
assign-queue 5
exit
class class_voip
mark ip-dscp ef
assign-queue 5
exit
exit
5 Attach the defined policy to an inbound service interface.
interface1/0/2
service-policy in pol_voip
exit
exit
Using SNMP to Configure DiffServ VoIP Support
1 Use the agentDiffServGenStatusAdminMode object in agentDiffServGenStatusGroup under
fastPathQOSDiffServPrivate in the FASTPATH-QOS-DIFFSERV-PRIVATE-MIB module to activate
DiffServ for the switch.
2 To set queue 5 on all ports to use strict priority mode, use the agentCosQueueSchedulerType in the
agentCosQueueTable in the FASTPATH-QOS-COS-MIB module. This queue is used for all VoIP
packets.
3 Use the agentDiffServClassRowStatus object in the agentDiffServClassTable to create two new
DiffServ instances. Se the value to CreateAndGo (4).
4 Use the agentDiffServClassName in the agentDiffServClassTable to name the first DiffServ classifier
“class_voip” and the second classifier “class_ef.”
5 Use the agentDiffServClassType in the agentDiffServClassTable to set the class type for each
classifier to All (1).
6 Use the agentDiffServClassRuleMatchEntryType in the agentDiffServClassRuleTable to set
class_voip to match a protocol (9) and class_ef to match an IP DSCP value (6).
7 For class_voip, define a single match criterion to detect UDP packets by setting the
agentDiffServClassRuleMatchProtocolNum in the agentDiffServClassRuleTable to 17.
8 Use the agentDiffServClassRuleMatchIpDscp object in the agentDiffServClassRuleTable to define a
single match criterion to detect a DSCP of EF (46). This handles incoming traffic that was previously
marked as expedited elsewhere in the network.
9 Use the agentDiffServPolicyRowStatus object in the agentDiffServPolicyTable to create a DiffServ
policy. Set the value to CreateAndGo (4).
Configuration Examples
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