Since the NPR supports Telnet and SNMP, can someone dial into the modem and gain access to a user's network?
Cybersecurity of the network is important, and any vulnerabilities should be identified and mitigated. IT professionals may ask about the Telnet and SNMP capabilities of an NPR and whether that represents a risk.
The NPR cannot initiate a Telnet session, therefore it will only respond to Telnet prompts. It cannot create an outgoing Telnet session into the local LAN.
It is also very limited in SNMP. It will respond to a query with a packet of information. That is all it can do. It does not conduct two-way or bi-directional communication.
Hackers can not use these modes to "leapfrog" into a local LAN.