PBX In-dialing

Claim 2

A telephone switching system comprising a central office having a marker-controlled switching network, a plurality of telephone stations at a remote switch unit, a plurality of trunks connecting said switch unit with said central office switching network, a stored program control unit for exchanging control information with said switch unit to establish communications connections among said stations and trunks thereat, and translator means including said control unit for furnishing the marker of said central office switching network with the (central office equipment location) identification of an idle one of said trunks serving called telephones at said switch unit.

Claim 3

A telephone switching system according to claim 1 further including interface circuit means, said stored program control unit and said marker of said central office switching network being connected with said interface circuit means.

Claim 4

A telephone switching system according to claim 2 wherein said stored program control unit includes command translator means and wherein said interface circuit includes gating means operable under control of said command translator means.

Claim 5

A telephone switching system according to claim 3 wherein said interface circuit includes means for receiving called telephone numbers from said marker of said switching network, means for translating said numbers into a code form acceptable to said stored program control unit, means for receiving said equipment location of said idle one of said trucks from said control unit and means for translating said equipment location into a code form acceptable to said marker.

Claim 6

A telephone switching system according to claim 4 wherein said means for receiving includes means for checking that said called telephone numbers received from said marker are in said form acceptable to said stored program control unit and wherein said gating means includes a first gate controlled by said command translator for transferring said called telephone numbers translated by said translating means to said stored program control and a second gate controlled by said command translator for transferring said called telephone numbers to said stored program control.

Claim 7

In a telephone switching system a plurality of remote switch units, a central office including an electronic control unit for said switch units, data transmission means between said electronic control unit and each of said switch units, a first and a second plurality of trunks connected to said central office, said central office further comprising number group translation means for identifying one of said trunks in said central office to which said central office is to establish a connection, marker means, means controlled by said marker means for obtaining from said number group translation means trunk identifications of said first plurality of trunks, and means controlled by said marker means for obtaining trunk identifications of said second plurality of trunks from said electronic control unit, said control unit thereupon controlling one of said switch units over said data transmission means to establish a connection to one of said second plurality of trunks at said switch unit and said marker controlling the establishment of a connection to said one of said trunks at said central office.

Claim 8

In a telephone switching system a plurality of remote switch units, a central office including an electronic control unit for said switch units, data transmission means between said electronic control unit and each of said switch units, a first and a second plurality of trunks connected to said central office, said central office further comprising number group translation means for identifying one of said trunks in said central office to which said central office is to establish a connection, marker means, means controlled by said marker means for obtaining from said number group translation means trunk identifications of said first plurality of trunks, and means controlled by said marker means for obtaining trunk identifications of said second plurality of trunks from said electronic control unit, said control unit thereupon controlling one of said switch units over said data transmission means to establish a connection to one of said second plurality of trunks at said switch unit and said marker controlling the establishment of a connection to said one of said trunks at said central office.

Claim 9

A telephone central office having a marker controlled switching network, a plurality of telephone stations at each of a plurality of remote switch units, a plurality of trunks connecting said switch units with said central office switching network, a stored program control unit for exchanging control information with said switch unit to establish communications connections among said stations and trunks thereat, means for connecting the marker of said switching network with said control unit when said switching netwoRk is processing a call incoming for one of said stations at one of said switch units, said connecting means including means for receiving from said marker the directory number of the called one of said stations, means for furnishing said directory number to said control unit, means for receiving from said control unit (the central office equipment location) identification of an idle one of said trunks serving the switch unit having said called one of said stations, and means for furnishing (said) the equipment location of said idle one of said trunks to said marker, means at said remote switch unit for determining when said marker has seized said idle one of said trunks responsive to said furnishing of said equipment location, and means at said control unit for instructing said switch unit to interconnect said one of said trunks with said called one of said stations.

Claim 10

A telephone central office having a marker controlled switching network, a plurality of telephone stations at each of a plurality of remote switch units, a plurality of trunks connecting said switch units with said central office switching network, a stored program control unit for exchanging control information with said switch unit to establish communications connections among said stations and trunks thereat, means for connecting the marker of said switching network with said control unit when said switching netwoRk is processing a call incoming for one of said stations at one of said switch units, said connecting means including means for receiving from said marker the directory number of the called one of said stations, means for furnishing said directory number to said control unit, means for receiving from said control unit (the central office equipment location) identification of an idle one of said trunks serving the switch unit having said called one of said stations, and means for furnishing (said) the equipment location of said idle one of said trunks to said marker, means at said remote switch unit for determining when said marker has seized said idle one of said trunks responsive to said furnishing of said equipment location, and means at said control unit for instructing said switch unit to interconnect said one of said trunks with said called one of said stations.