There have also been rumors about Amdocs [1] being kind of the Israeli counterpart. They do billing for telcos (i.e. determine who talked to whom for how long). The list of their customers is quite impressive.
These 'rumours' are more like an open secret inside the industry.
Personally I have seen billing APIs at AT&T (US) and T-Mobile (US) which are semi-equivalent. For one of those, calls go straight to an Amdocs domain on an AS hosted outside of the carrier. Of course, few people will see these now since Google Play canned external billing APIs (removing most of the interest here) and most new projects choose to access carrier billing via international aggregators (since integrating with one carrier can take months of pain, if you even have enough of a case to bother, and if they even talk to you). For NFC stuff, most US carriers are combining forces to produce a new API which will effectively similarly distance any integrators. The reason I got a look was we were developing the flagship app for Samsung Galaxy series device launch in the US, and the carriers were all on board with it.
An older, long term IT veteran friend of mine who recently retired in Australia and chaired the mobile phone number portability multi-carrier technical implementation roundtable told me he was essentially fired (contract not renewed) for opening up an inquiry in to the wasteful billing practices at one particular Australian carrier. It turned out they were using Amdocs. He described making a decision, being forced to sit through a presentation, making the same decision, being forced to sit through another presentation, until the end of this contract period.
This and other sources concur: the Amdocs billing stuff's like cancer. Once they're in your network, you can't get rid of them. If I were a national privacy authority or the European Data Protection Supervisor, I'd walk in to all my carriers, seize all third party billing systems, dump out disk images, and analyze them top to bottom in a nationally transparent, multi-party audit citing national security / privacy.
We have been talking about this since the 80s....