Must admit I've got rusty. I happened upon this whilst searching on the 'net for another matter - the AUSTRALIAN STANDARD AS/ACIF S009:2006 "Installation requirements for customer cabling (Wiring rules)" - Page 141 Figure J4 explains the network boundary in the typical detached house scenario.
NOTE - you must be a registered cabler or working under the supervision of a registered cabler to perform work, modify, disconnect any part of the "telecommunications network."
Microsoft Word - S009_2006r V2.doc (commsalliance.com.au)
Note the warning re potentially hazardous voltages on Page v -
WARNING
This Standard includes requirements
intended to ensure the safety of
customers, cabling providers, carrier staff,
and the general public. However, cabling
providers are reminded that metallic
telecommunications conductors, earth
connections, metallic parts, etc. may, at
any given time, be at a voltage that
exceeds the Telecommunications
Network Voltage (TNV) rating of
AS/NZS 60950.1. Examples of an
overvoltage condition may include:
• contact with AC mains power through
customer equipment failure or cabling
faults;
• power feeding;
• surge currents and induced voltages
through power system faults.
Accordingly, cabling providers working
on customer cabling are warned to treat
the metallic parts of a
telecommunications installation as
potentially harmful.
Note: A carrier may disconnect customer equipment or customer cabling
that is, or is likely to be, a threat to the health or safety of any person
or the integrity of a telecommunications network or a facility.