2G GSM piggybacked its wired backed on the ISDN telecom standard (which is which your phone number is called a MSISDN).
Today's CAMEL (MAP and CAP) signalling is an evolution of the ISDN signalling which traces it roots back into (amongst others) the SINAP signalling protocol and the SS7 network stack from even before that.
SS7 is early 1970s stuff. From a more innocent time.
Today's CAMEL (MAP and CAP) signalling is an evolution of the ISDN signalling which traces it roots back into (amongst others) the SINAP signalling protocol and the SS7 network stack from even before that.
SS7 is early 1970s stuff. From a more innocent time.