Granted Patent
Utility
US 6,381,249 · App. 09/074,868
Tandem pass through in a switched call
Inventors:
Christina Chan, Lois M. GREER
Patented Case
View Patent ↗
Granted: Apr 30, 2002
Filed: May 8, 1998
Inventors
Christina Chan
Lois M. GREER
Assignee (at issue)
Nortel Networks Limited
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.