patm device on FreeBSD 9.2

[Nomad Esst]

I've recently configured my kernel with the following options    device        patm 
    device        utopia 
    device        atm 
    options       NATM 
    options       LIBMBPOOL 
In order to use patm device on my FreeBSD 9.2 AMD64.Here are the configurations for a back to back connection 
    ifconfig patm0 10.10.10.1 255.0.0.0 
    atmconfig natam add 10.10.10.2 0 100 aal5 
 
after setting these configurations, I can not even ping the other side! Another problem is that using tcpdum on patm0 interface causes the following error: 
    tcpdump:    patm0: No such device 
    (BIOCSETIF failed: Device not configured) 
 
Please help me using this device on my system. 
Thanks in advance ...