Establishing a telephone call would be impossible without signaling.

true or false

 True.

Explanation:

When a user wants to make a phone call, he needs to inform to the called party, that he wants to call him.

The only way to do this, is setting up a connection between the two phones, which is started by the calling party informing to the phone switch which is directly connected to, that he wants to make a call, picking up the phone, which modifies his connection state, making him available for calling.

The switch then signals him (sending him an audible call tone) so he can send the digits that identify the called party.

When the destination switch identifies the called user, signals him also (sending in this case a ringing tone).

When he picks up his phone, answering  the call, the connection is set up, and both people can talk each other.

Without all this signaling process, it would be completely impossible to set up the call.