(12) United States Patent ao) Patent No.: Us 7,480,260 Bi
Vashisht et al. (45) Date of Patent: Jan. 20,2009
(54) METHOD AND APPARATUS FOR
IMPLEMENTING A PRESENCE-BASED
UNIVERSAL CAMP-ON FEATURE IN
PACKET-BASED TELEPHONY SYSTEMS
(75) Inventors: Vikas Vashisht, Naperville, IL (US);
Anoop Tripathi, Lake Zurich, IL (US);
Jaideep Abichandani, Carol Stream, IL
(US); Hui Dai, Itasca, IL (US)
(73) Assignee: 3Com Corporation, Marlborough, MA (US)
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 840 days.
(21) Appl.No.: 10/845,382
(22) Filed: May 13, 2004
(51) Int. CI.
H04L12/66 (2006.01)
H04M 3/42 (2006.01)
(52) U.S. CI 370/260; 370/271; 370/352;
370/209.01
(58) Field of Classification Search None
See application file for complete search history.
(56) References Cited
U.S. PATENT DOCUMENTS
5,268,957 A * 12/1993 Albrecht 379/209.01
6,363,065 Bl * 3/2002 Thornton et al 370/352
6,665,293 B2 * 12/2003 Thornton et al 370/352
7,065,197 Bl* 6/2006 Ramella
Pezzaetal 379/201.02
7,218,722 Bl* 5/2007 Turner et al 379/221.02
7,280,530 B2* 10/2007 Chang et al 370/352
SUBSCRIBE FIRST PACKET-BASED TELEPHONE TO
LINE STATUS OF SECOND PACKET-BASED TELEPHONE
RECEIVE NOTIFICATION INTO FIRST PACKET-BASED
TELEPHONE THAT THE LINE STATUS OF SECOND
PACKET-BASED TELEPHONE IS IN A BUSY STATE
RECEIVE NOTIFICATION INTO FIRST PACKET-BASED
TELEPHONE THAT THE LINE STATUS OF SECOND
PACKET-BASED TELEPHONE IS IN AN IDLE STATE
PROMPT USER OF FIRST PACKET-BASED TELEPHONE
WITH OPTION TO ESTABLISH COMMUNICATION
SESSION WITH SECOND PACKET-BASED TELEPHONE
ESTABLISH COMMUNICATION SESSION
BETWEEN FIRST PACKET-BASED TELEPHONE
AND SECOND PACKET-BASED TELEPHONE
