Title:
KEY TELEPHONE SYSTEM WITH POWER FAILURE FUNCTION
Document Type and Number:
Japanese Patent JP3470877
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a key telephone system with a power failure function capable of immediately performing the call control of call origination and termination to a network even when a main device is changed from an energizing state to a power restoration state and from the power restoration state to the energizing state.
SOLUTION: When energized, after TEI (terminal identification point identifier) allocation from the network, the main device 1 makes the TEI and a housing line number correspond and an extension slave unit 2 stores the TEI informed from the main device 1 in a main device interface part 2-2 and informs the main device 1 first of the TEI used in a power failure when power is restored. Every time the main device 1 is changed from the energizing state to the power failure state or vice versa, the informed TEI is used and the transmission and reception of call control information to the network are performed.
Inventors:
Kazuo Kitamura
Application Number:
JP30544398A
Publication Date:
November 25, 2003
Filing Date:
October 27, 1998
Export Citation:
Assignee:
Nippon Telegraph and Telephone Corporation
International Classes:
H04M19/00; H04L12/02; H04L12/40; H04M1/715; H04M3/00; H04M11/00; H04Q3/58; (IPC1-7): H04Q3/58
Domestic Patent References:
| JP258497A | ||||
| JP670388U |
Attorney, Agent or Firm:
Masataka Kobayashi