Telemachus in Homer's Odyssey and Orestes in Aeschylus' Oresteia are both portrayed as loyal sons to their fathers, albeit in very different circumstances.
In the case of Telemachus, his father Odysseus has been delayed in returning from Troy. The suitors are threatening to usurp the place of Odysseus and marry Penelope. Telemachus' journey to find news of his father serves as a coming of age for him, taking on the responsibilities of a grown man in an arduous and dangerous journey. In many ways, he honors Odysseus not just by his faith in his father's return and his efforts to preserve the household, but also in the way he grows in wisdom and courage and emulates his father.
Orestes is in a somewhat different situation. His father Agamemnon has been killed by his mother Clytemnestra in revenge for Agamemnon's having killed Iphegenia. Perpetuating a cycle of blood vengeance, Orestes kills Clytemnestra to honor his father by avenging his death.