I can tell you that even a meager telco that I've worked for has very good security to their PKI equipment and none of it is networked. Has had since before stu

I can tell you that even a meager telco that I've worked for has very good security to their PKI equipment and none of it is networked. Has had since before stuxnet became known. And they don't even manufacture hardware. If you manufacture hardware and distribute drivers you are an even bigger target than a telco.