Perhaps "SP" is the wrong service. Try "sdptool search A2SNK xx:xx:xx:xx:xx:xx" for your bluetooth headset. Please read the manpage of sdptool or the manual of your device to figure out the proper service type/bluetooth profile. I'm at work so i cannot test Dennis Heitmanns solution for the problem.
Perhaps "SP" is the wrong service. Try "sdptool search A2SNK xx:xx:xx:xx:xx:xx" for your bluetooth headset. Please read the manpage of sdptool or the manual of your device to figure out the proper service type/bluetooth profile. I'm at work so i cannot test Dennis Heitmanns solution for the problem.