packet-generator new {
  name ipsec_udp6
  rate 10
  node ip4-input
  size 64-64
  no-recycle
  data {
    UDP: 192.168.10.31 -> 192.168.20.32
    UDP: 15320 -> 8080	
    length 128 checksum 0 incrementing 1
  }
}