When running linux, you sometimes want to connect to a cell phone (using it as a modem) over bluetooth.
Different cell phones use different RFCOMM channels to export their Dial-up Networking service on.
Here are the commands to use to find which channel you should use:
hcitool scan – This command gives you a list of all the bluetooth devices in the area, and their associated BDADDR's. Look for your phone, and note the BDADDR.
sdptool search –bdaddr <YOUR_BDADDR> DUN – This command will return the correct channel to use, with a result something like this:
Service Name: QC Dial-up Networking
Service RecHandle: 0x10007
Service Class ID List: "Dialup Networking" (0x1103)
Protocol Descriptor List: "L2CAP" (0x0100) "RFCOMM" (0x0003)
Then you can set up an rfcomm.conf file as follows (Note the use of Channel eight):
# Automatically bind the device at startup
# Description of the connection
comment "Jay's Phone";