Odd QoS DSCP marking behaviour on 3945 Router

[Ella Bella]

I have a simple QoS config, that matches RTP and SIP traffic and marks the packets with DSCP values. The weird thing is - it takes exactly 4 minutes after the call is initiated before the packets start getting marked! What on earth could be causing this? Ive never seen this behaviour before.

Heres my QoS config:

class-map match-any CM-classify-rtp

match protocol rtp

match ip precedence critical

class-map match-any CM-classify-signalling

match protocol sip

match ip precedence flash

policy-map PM-classify-in

class CM-classify-rtp

  set ip dscp ef

class CM-classify-signalling

  set ip dscp af31

interface gigabitethernet 0/0.2

encapsulation dot1q 2

ip address 10.131.2.4

ip nbar protocol-discovery ipv4

service-policy input PM-classify-in

[Mohammed al Baqari]

Hi,

On Gig0/0 interface apply the command ' load-interval 60' and see if it makes a difference. 

[Ella Bella]

Hello, I applied the load-interval 60 command and there is no change to the behaviour. Thanks for the suggestion!