Is it forbidden to say "hello" before "peace be upon you" in phone calls?

Initiating the salutation (salam) is a Sunnah according to the majority of scholars. It is recommended for it to precede all speech, and it is disliked to begin speaking before the salutation. It is legislated for the one responding not to answer someone who did not initiate with the salutation. However, not initiating the salutation is not forbidden, as the salutation is not originally obligatory.