ATIS Telecom Glossary
Wednesday, July 23, 2014

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office classification
Prior to divestiture, numbers that were assigned to offices according to their hierarchical function in the U.S. public switched telephone network. Note 1: The following class numbers are used:

  • Class 1: Regional Center (RC)

  • Class 2: Sectional Center (SC)

  • Class 3: Primary Center (PC)

  • Class 4: Toll Center (TC) [Only if operators are present; otherwise Toll Point (TP)]

  • Class 5: End Office (EO) [Local central office]

Note 2: Any one center handles traffic from one center to two or more centers lower in the hierarchy. Since divestiture, these designations have become less firm.

 

 

 

 

 

 

 

 

 

 



 
These definitions were prepared by ATIS Committee PRQC
 
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