Problem to link GPS to u center

Hey guys ,

I have an issue to connect my BN 800 GPS to my PC .

I buy an FTDI cable and one this FTDI I have 6 cable : RTS, RX, TX, 5V, CTS, GND
On the GPS I have also 6 ports : GND , VCC, SDA,SCL,RXD,TXD

So my question is : to what port correspond what cable ?

Thank you