The perspective of the Phaedo is three-fold. The explicit perspective in the text is that of Phaedo, who tells Echecrates about his experience with Socrates at his death. Periodically in the dialogue, Phaedo and Echecrates will summarize what is going on in the story and review the state of the argument. However, this perspective is only Phaedo's perspective, which is a proxy for both relating Socrates's ideas and expressing Plato's.
Plato's Phaedo