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Telephone exchange system

  • US 5,651,061 A
  • Filed: 03/31/1995
  • Issued: 07/22/1997
  • Est. Priority Date: 09/01/1993
  • Status: Expired due to Fees
First Claim
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1. A telephone system comprising:

  • an exchange sub-system containing a plurality of trunks; and

    a plurality of terminals directly connected to the exchange sub-system by lines for executing a communication operation in cooperation with call connection control of said exchange sub-system connected thereto; and

    said exchange sub-system having output means for outputting trunk information through the lines, the trunk information indicating a state change of one of said trunks to all of said terminals when a state of said one of said trunks changes, whereineach of said terminals further includes;

    a trunk table for storing the state of said trunks;

    rewriting means for rewriting the state of said trunks stored in said trunk table in response to reception of said trunk information; and

    control means for controlling said exchange sub-system to connect an incoming call to said respective terminal and to connect an outgoing call made from said respective terminal according to the state of said trunks in said trunk table,wherein the control means determines if one of said trunks is available for setting up the outgoing call through said one of said trunks by determining if said one of said trunks has a corresponding state that indicates availability for use, andwherein the control means determines if any of said trunks is currently available for use by said respective terminal for the incoming call based on other call connections currently being utilized by said respective terminal.

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