For outbound call hunting you can use Trunk groups. You can assign multiple fxo ports to the trunk group and assign them priorty etc. From your dial-peer reference the trunk group and it will hunt the available line.
Refer to: http://www.cisco.com/en/US/docs/ios/12_3/vvf_r/vrg_t1_ps1839_TSD_Products_Command_Reference_Chapter.html#wp1491022
Also Refer: https://supportforums.cisco.com/discussion/12056631/need-sample-cme-multiple-fxo-ports-hunt-fashion
-Terry
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