Issued Patents All Time
Showing 1–3 of 3 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5521967 | Method for monitoring telephone call progress | Andy Spitzer | 1996-05-28 |
| 5325425 | Method for monitoring telephone call progress | Andy Spitzer | 1994-06-28 |
| 5023906 | Method for monitoring telephone call progress | — | 1991-06-11 |