ISDN User Part or ISUP, a feature of Public Switched Telephone Networks
Arvo Pärt | User Datagram Protocol | Graphical user interface | graphical user interface | User interface | Harry Potter and the Deathly Hallows – Part 1 | The Godfather Part II | Friday the 13th Part III | User interface design | Henry VI, Part 2 | Henry IV, Part 1 | Harry Potter and the Deathly Hallows – Part 2 | user interface | user experience | The Twilight Saga: Breaking Dawn – Part 1 | The Decline of Western Civilization Part II: The Metal Years | Rambo: First Blood Part II | Till Death Us Do Part | Part 2 | Friday the 13th Part 2 | Back to the Future Part II | user | The Snake King's Wife Part 2 | Part-time | History of the World, Part I | End of Part One | Atlas Shrugged: Part I | User (telecommunications) | User profile | user experience design |
Media Gateway Controller talk with each other using SIP, H.323 or ISUP