You can use your iPhone’s Voicemail button to call your local carriers voicemail number by doing the following:

1. Disable your SIM PIN, if enabled.


2. SSH into your iPhone – I’m going to assume your iPhone has been jailbroken, has SSH installed and the latest BSD Subsystem installed.


3. The latest BSD Subsystem (1.5) comes with minicom, but you’ll need to generate a configuration file for it to interact with the baseband. You’ll need to create /local/etc/ in /usr/.


4. In /usr/local/etc/, run nano minirc.dfl and paste “pu port /dev/tty.baseband”


5. Save the file, CTRL-O, exit nano CTRL-X


6. Disable the commcenter – launchctl unload w /System/Library/LaunchDaemons/com.apple.CommCenter.plist
   


7. Run minicom


8. Run AT+CSVM=1,“171” where 171 is your carriers voicemail number


9. Exit minicom – CTRL-a, then q


10. Restart the commcenter launchctl load -w /System/Library/LaunchDaemons/com.apple.CommCenter.plist

Done!