How does a signal switch work?

Hey Adam,
just one more little question:

Do i need to terminate my differential lines coming from a 50 Ohm source interfacing with the TS3L110? So for instance a 100 Ohm differential termination at the TS3L110 input. My maximum frequency is 100MHz. i am still not sure I understand how the switch works, assuming it would only work as a resistor (Ron approx. 8 Ohm) I would not need termination. But I hardly believe that. But on the other hand, i don't see any datasheet entry for input or uptut resistance...

so what is this black magic switch? ;)

bestr regards