cristian;
You can start gpsd with a command that tells it to connect to and receive data from one or more tcp/ip address/ports for data.
Two examples:
Connect to localhost on port 12045. Use read-only mode. Turn off debugging output.
gpsd -b -D0 -tcp://localhost:12045
Connect to localhost on port 12045 and to
aishub.net on port 5918. Use
read-only mode. Set debugging output to level 1.
You can use -b and -D as you see fit. -b is often a good idea, particularly with net connections. -D>0 can output useful debugging info to stdout (unix/linux) if problems occur.