What is the dramatic importance of the ring episode in Shakespeare's The Merchant of Venice?

In The Merchant of Venice, the ring that Portia gives her suitor, Bassanio, symbolizes their commitment. Disguised as Balthasar, a lawyer, she argues at the trial to save his friend Antonio’s flesh. Still in disguise, she accepts the ring from Bassanio as partial payment for her having saved Antonio. Restored to her true identity as Portia, she asks her beloved to see the ring, which he cannot produce. This inability leads to her accusation of infidelity, which Bassanio vigorously denies. When she reveals she has the ring, she also jokes around that she had gotten it back via a sexual encounter.
After she reveals that she had been playing Balthasar, they agree that it was acceptable for Bassanio to use the ring because it showed his devotion to his friend. Although it might seem that Bassanio did not adequately appreciate his fiancée’s gift, the difference between the symbolic and material value of the ring is stressed. The episode is a confirmation that Bassanio is a good, loyal person whose interested in marrying Portia is not her economic status, which the ring also represented.