Re: City Party Line Service

ONI (Operator Number Identification) was the norm for anything above a

> two-party line at least for the Bell System or at least it was ...

Correct.

They could get it (ANI) from two-party lines, but nothing higher.

The earliest "ANI" was in early long distance where a "checking multiple" was used to confirm the subscriber's number. (I think this was with panel). The operated tested a button and heard a confirmation tone. According to the NYT on this, only two instances of many thousands of calls were incorrect. I suspect it was more.

In NYC, panel had meters on subscribers lines for message rate service. These were also done under manual service, but apparently the operator had to press a key to register the call and often forget. Operator timing beyond the 5 minute period was also inconsistent. I'm not sure when and how NYC implemented timing and distance on panel meters (message units), I don't think it was present at the beginning. Distant calls were intercepted by the operator who placed it as a toll call with a ticket. Even then they used some push button consoles.

A later ANI was in Los Angeles with their early (1940s) automatic ticketing system for short long-distance toll calls. It was some hairy tech stuff involving electronics added to the SxS exchanges (see Bell Eng & Sci history.)

When DDD came out. ONI was needed in a great many places since ANI wasn't that easy to do. I wonder if there was any checking.

The modern No. 4 ESS included a link to a TSPS for ONI purposes if ANI wasn't received, such as from 4 party lines. Interesting how modern technology still had to provide backward links to old stuff for compatibility purposes.

P.S. NYC converted from 3L to 2L PEN to PE-6 around 1931.

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hancock4
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