This is a classic can you help a friend situation. After I talked to AT&T, the gateway (unreachable via its IP address) began passing local addresses starting with 172.16.1.xxx. The LTS/Hikvision passed its own addresses to each camera. LTS tech-support is phenomenal, and was able to remote in and get all the cameras working.
I got him up and running but know I don’t have good troubleshooting skills for this.
There is no truth anymore. Only assertions. The internet world has no interest in truth, only vindication for preconceived assumptions.