Special AgentBT This “special“ software installed on all modems provided by BT called BTAgent.
This software listens on port 161, which is the IANA assigned port for Simple Network Management Protocol (SNMP), anyone looking at this process would
automatically assume this to be the case. SNMP type programs are often referred to as SNMP Agents.
The primary purpose of BTAgent is unpublished, but a version has been partially reverse engineered and the software does download firmware and
update the modems flash.BT responses to queries about their BTAgent is to claim that they need to
“remotely manage modems for security purposes”.