Sorry for typo in issue 1, please see my updated as following, if re-injection is need then both VoIP and DSL just can pass 1.5KV.
>>If TDC can agree that VoIP and DSL just need to pass CE requirement (1.5KV), ignore 6KV requirement, then this issue will be okay.
Explain: When we apply 6KV in DSL pair (pin) 3 & 4, the voltage will easy to jump to pin 2 & 5. It means VoIP port will be attack by 6KV as well!