SRX300 cos on st0 and ge-0/0/0

Dear Professional,

we have 2 subnets, 192.168.15.0/24 on ge-0/0/1.0 and 192.168.5.0/24 on ge-0/0/2.0. ge-0/0/0.0 is connected to WAN.

We setup IPSEC VPN from the subnet 192.168.5.0/24 and assign to st0.1.

We would like to setup COS so that the VPN traffic has the higher priority to consume all available bandwidth. The remaining bandwidth is for subnet 192.168.15.0/24. If there is no VPN traffic, the subnet 15.0/24 can consume all bandwidth.

Most of the examples are using shaping-rate either under virtual channel groups or Schedulers.

Is there any idea or documents that i can achieve?

Thanks in advance.

Regards,

Ken.