From: 71336.1270@CompuServe.COM (tim gorman)
Newsgroups: comp.dcom.telecom
Subject: Some Additional Thoughts About ANI
Organization: TELECOM Digest

Pat,
 
Several people have given several good explanations of the
philosophical differences between ANI and Caller ID. Let me throw in
some information that has not yet been covered.
 
The statement that ANI is used for billing is correct. It is used for much
more than that, however. Depending on the call classification (FG C, FG D,
etc.) there are one or two information digits included which are used to
classify either the ANI type or station class. For instance:

              00 = VALID ANI
              01 = Operator ID required
              02 = ANI Failure
              07 = Special Screening Station
 
There are several more, some of which are valid only on FG D calls.
 
A typical MF transmitted ANI string looks as follows:

  KPx + II + (3/7/10D)ANI + STx    (II designates the info digits)
 
Depending on the call type and ANI protocol in use the KP and ST
signals are used to indicate things ranging from whether 1+ or 0+/0-
was dialed, whether the station is coin or non-coin, whether the
originating station is touchtone or rotary dial, and whether 10XXX +
0/1 or just 0/1 was dialed.
 
The receiving office uses all of this information to correctly process
the call as well as bill it.
 

Tim Gorman - SWBT
* opinions are my own, any resemblence to official policy is coincidence*