06252952 is referenced by 274 patents and cites 60 patents.

An Internet Protocol Telephony Network and public switched telephone network, in which closed user groups may be dynamically defined and modified to take advantage of special billing within the closed user groups. Abbreviated dialing within the closed user groups may also be used to make dialing more convenient. The closed user groups may include members anywhere in a global network, and may take advantage of the special billing, regardless of whether the members are located in different states and/or countries.

Title
Personal user network (closed user network) PUN/CUN
Application Number
9/475295
Publication Number
6252952 (B1)
Application Date
December 30, 1999
Publication Date
June 26, 2001
Inventor
Spencer Wang
Parsippany
NJ, US
Hopeton Walker
Haledon
NJ, US
Jesse Eugene Russell
Piscataway
NJ, US
Fen Chung Kung
Bridgewater
NJ, US
Assignee
AT&T
NY, US
IPC
H04M 15/00
View Original Source