if you QoS for VoIP over PPP WAN Links
example:
class-map voip
match ip precedence 5
!
class-map webtraffic
match ip precedence 3
!
policy-map llq
class voip
priority 64
class webtraffic
bandwidth 64
class class-default
fair-queue
!
interface Serial1/0
bandwidth 256
encapsulation ppp
no fair-queue
ppp multilink
multilink-group 1
!
interface Multilink1
ip address 10.1.1.1 255.255.255.252
bandwidth 256
!
ip rtp header-compression iphc-format
ip tcp header-compression iphc-format
!
ppp multilink
ppp multilink fragment-delay 10
!
ppp multilink interleave
!
multilink-group 1
service-policy output llq
!