Long distance phone tracing used to require calling from switch operator to operator while the circuit was active, -- the only unrealistic part is their visuali

Long distance phone tracing used to require calling from switch operator to operator while the circuit was active, -- the only unrealistic part is their visualization of the trace progress and the era-inappropriateness of that kind of tracing. One could imagine knowing trace progress if one imagined they'd also compromised the transit exchanges well enough to see if someone was accessing the service console.