This sample configuration initially uses Profile 1 to assign Priority 3 to all incoming traffic, VLAN-tagged or not. After an IP Phone is detected on a port the E1 uses Profile 2 on that port to communicate (via CiscoDP) the desired Voice VLAN Identifier (VVID) to the IP Phone and treat all of the phone's incoming VLAN-Tagged traffic - identified by means of an IPTOS value of 0x60 (decimal 96) - as Priority 5, while continuing to treat all other traffic (such as untagged traffic from the IP Phone's attached PC) as Priority 3. The IP Phone traffic will thus use Transmit Queue# 2 while all other traffic uses the lower-priority Transmit Queue# 1.
The IP Phone responds to the VVID information by using it in its 802.1Q VLAN Tags and the E1 has been configured to egress that VLAN as Tagged, while the attached PC's traffic remains untagged and is VLAN-assigned based on the port's PVID - which in this configuration remains at its default value of 1, with untagged VLAN 1 egress.
The 5-second CiscoDP timer helps to ensure that the IP Phone knows what VLAN it is supposed to use before it starts sending network traffic, including DHCP. The default timer is 60 seconds.
! priority classification
set priority classification qtagoverride fe.0.1-48 enable [Allow Pri=5 for Tagged traffic]
! ciscodp
set ciscodp timer 5 [Give the phone the VVID ASAP for DHCP]
!
! policy profile
set policy profile 1 "default" disable 0 enable 3 [Force Pri=3 for all traffic]
set policy profile 1 enable [ and enable it]
set policy port fe.0.1-48 1 [Profile 1 is a port-based policy for all]
set policy profile 2 "IP phone" disable 92 enable 3 [Use VVID=92, Force Pri=3 for non-Voice]
set policy profile 2 enable [ and enable it]
set policy classify 2 1 cos 5 iptos 96 [Force Pri=5 if IPTOS=0x60 (Voice)]
!
! cep
set cep enable [Enable Convergence End Point]
set cep port fe.0.1-48 cisco enable [Set all ports to use CEP/CiscoDP]
set cep policy cisco 2 [Use CiscoDP to invoke Profile 2]