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    | n | Introduction 
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    |  | 
   
    |  | n | review of early 
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    |  | exchanges 
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    |  | 
   
    |  | n | PSTN Standards 
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    |  | 
   
    | n | User services
    & terminals 
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    |  | 
   
    | n | Modern exchange
    technology 
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    |  | 
   
    |  | n | interface
    standards 
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    |  | 
   
    |  | n | access and
    trunk networks 
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    |  | 
   
    |  | n | signaling 
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    |  | 
   
    |  | n | network
    management 
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    |  | 
   
    |  | n | internetworking
    (telecommunications between networks) 
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