Exactly. Back in the early 2000s there was a flurry of activity as telcos replaced old Nortel and Lucent TDM switches with IP ones made by CopperCom, Metaswitch

Exactly. Back in the early 2000s there was a flurry of activity as telcos replaced old Nortel and Lucent TDM switches with IP ones made by CopperCom, Metaswitch, Taqua and the rest but a lot of that was funded by govt funds (eg USDA RUS) and even then those companies could not do anything about the copper access wiring leading into tbeir shiny new switches. So you had this weird situation where a sleek, all IP softswitch was talking IP to a gateway which spoke some TDM thing to an even older SLC96 with a gazillion copper loops hanging off of it. I think that all those companies are dead or acquired now.