bluetooth rfcomm

http://www.piaccess.com/trac/wiki/Linux_BlueZ_Bluetooth_Serial_Setup
http://blog.mcuol.com/User/kynot/Article/7049_1.htm
 About rfcomm arugement "channel"
 http://ubuntuforums.org/showthread.php?t=200142

rfcomm  usage:
rfcomm <command> <Bluetooth Device> <BD Address> < Channel>

# rfcomm bind hci0 00:07:A4:D2:03:67 1
#ls -l /dev/rfcomm0
crw------- root root  <time>  rfcomm0
# hcitool cc 00:07:A4:D2:03:67