Most VoIP vendors implement proprietary technologies that permit such handoff between equipment of their own manufacture, e.g. the Viera system from Panasonic.
The Appleseed Cast | cast iron | Cast Away | ensemble cast | Viera, Florida | The cast of ''Mujhse Fraaandship Karoge''. From left: Saqib Saleem | List of Carry On films cast members | Cast iron | Cast (band) | Cast | cast | ''SNL'' cast | Saint-Cast-le-Guildo | Jesus Christ Superstar (Original Australian Cast Recording) | Ensemble cast | Die-cast toy | Cast Your Fate to the Wind | Cast the First Stone | Cast of the 1979 Steffenwolf production of Ralph Pape's ''Say Goodnight, Gracie'': Joan Allen | Cast a Dark Shadow | CAST | American Cast Iron Pipe Company | West Side Story (Original Broadway Cast) | Walk in sculpture park by ''Cast Glances'' by Tony Cragg | Viera Ellong | Viera Cast | Viera | ''Varhey Circle Fountain'', cast concrete fountain by Henry H. Rempel | Vanities' Cast Recording | The Powis Terrace loft where the cast of ''The Real World: London |