These are the steps I took to gain Internet access over Bluetooth through my Nokia 6233 on OpenBSD 4.5-current. There was no way I was going to pay 75 EUR for the USB cable to my phone, which would have made this process a lot easier (see this page).
The following notes assume a properly configured phone, and keep in mind that you probably have to change a few things at your end to get this going (the chat script most likely). This is not a general HOWTO, just my notes on what I did and what worked for me.
Make sure your Bluetooth device is recognized by OpenBSD:
$ dmesg | grep ubt ubt0 at uhub4 port 1 "Micro Star International Bluetooth" rev 2.00/32.64 addr 2
Install the bluetooth-tools package. This provides tools like btconfig(8), btpin(1), rfcomm_sppd(1):
$ sudo pkg_add bluetooth-tools
Bring the Bluetooth interface up and verify that you're able to detect your phone:
$ sudo btconfig ubt0 up
$ btconfig ubt0 inquiry
Device Discovery from device: ubt0 .... 1 response
1: bdaddr 00:1d:e9:e5:ad:01 (phone)
: name "Nokia 6233"
: class: [0x5a0204] Cellular Phone <Networking> <Capturing> <Object Transfer> <Telephony>
: page scan rep mode 0x01
: clock offset 27997
Add the bdaddr to /etc/bluetooth/hosts so you don't have
to type in the address every time you want to refer to your phone:
# echo "00:1d:e9:e5:ad:01 phone" >> /etc/bluetooth/hosts
Start bthcid(8), generate a pin using btpin(1) and connect to your phones' Dial Up Networking (DUN) service using rfcomm_sppd(1).
$ sudo /usr/local/sbin/bthcid $ btpin -a phone -r -l 4 PIN: 2701 $ rfcomm_sppd -d ubt0 -a phone -s DUN rfcomm_sppd[16519]: Starting on stdio...
You should receive a question on your phone if you want to accept the connection and then type in the PIN generated above. You should now be able to communicate with your phone:
AT OK ATI3 Nokia 6233 OK
Now that we know this works, we can attach it to a pty:
$ rfcomm_sppd -d ubt0 -a phone -s DUN -t /dev/ttypz $
Create a ppp interface and connect using pppd(8):