tomtom serial connection

[Vittorio De Martino]

I read in the internet that it is possible to connect the tomtom go gps to a 
computer via bluetooth as a serial connection therefore  allowing a gps 
program such as gpsdrive to read nmea data from it.

If I 

victor$ sdpcontrol -a tomtom browse

Record Handle: 00000000
Service Class ID List:
        Service Discovery Server (0x1000)
Protocol Descriptor List:
        L2CAP (0x0100)
                Protocol specific parameter #1: u/int/uuid16 1
                Protocol specific parameter #2: u/int/uuid16 1

Record Handle: 0x00010000
Service Class ID List:
        Browse Group Descriptor (0x1001)

But trying to connect it to a serial device:

victor$ rfcomm_sppd -a tomtom -t /dev/ttyp6
rfcomm_sppd: Could not obtain RFCOMM channel: Attribute not found


How can I make it?

Ciao
Vittorio