I worked for a bunch of years in biggest Israeli company that is selling OSS/BSS and related outsourcing services to telecoms (those who can afford it's solutio

I worked for a bunch of years in biggest Israeli company that is selling OSS/BSS and related outsourcing services to telecoms (those who can afford it's solutions), and had some first hand experience with them >Since the early 2000s at least, most billing has been outsourced. This works by sending all Call Detail Records (CDRs) to a third party, often from Israel or China. A CDR stores who called whom and for how long. More data might be attached, for example the location of the customer, or where the customer was roaming abroad etc. Don't know about software from China, but the one that we sold doesn't send anything back to Israel. There are a lot of rules and restrictions upon CDRs and we had a bunch of training with regards to it. Everything is running on client site, usually on hardware deployed by us at their data centers and managed by dedicated team of people who relocate to live next to the client in order to provide 24/7 support of the systems on site >Typical service providers have hundreds of thousands of network elements. Surprisingly perhaps, many of these are actually maintained manually (!). Thousands of networking engineers labour to keep all this infrastructure operating well. This is a mix of half-truths and lies. None of the operators have thousands of people to manually configure day-to-day network stuff. Operators have rather sophisticated automation systems (aka OSS) that deal with provision and configuration of everything in their networks. Or almost everything. Any given operator whose life span is a decade or two today has a boatload of equipment (thousands of different types of hardware from same amount of vendors). In many cases this equipment was bought and deployed 10 or 20+ years ago. Companies that made it do not exist for many years. This hardware can't be replaced with anything, because nobody does this type of systems anyway. Those systems tend to have proprietary interfaces and in many cases can be managed only through Element Manager which can be managed only manually through some ancient windows or java application. >Meanwhile, modern large scale internet companies (like Google, Netflix, Facebook) have automated all such maintenance. Automation in this context means that no configuration states are edited manually but instead, entire networks get provisioned and configured from central templates. >With such automation, small teams of engineers can control and operate vast networks with relative ease - especially if good use is made of continuous integration and real life testing. I also worked for a while in one of FAANGS. They have it easy: all the hardware with modern with nice interfaces. You can actually automate it. Also their networks are much-much smaller compared to mid-sized telecom, much simpler and much more homogeneous. Automation that FAANG I worked for was a joke compared to automation systems that run telecom networks. My job was near network engineering team and during conversations they admitted that what they have is crap. I believe that at one point of time they considered to buy telecom level OSS system but bailed out because they couldn't get a source code .