descobri que a porta 8085 estava aberta e executando um serviço TCP
Você deve perguntar à BT.
De uma postagem no fórum da comunidade da BT (veja abaixo):
I suspect this is the port used by BT for external access but I need confirmation.
...
It could be the TR-069 WAN management system or another BT service running a session on that port.
O TR-069 é um padrão para o gerenciamento remoto de dispositivos de usuários finais.
A porta 8085 é aberta, o que ela faz?
Even though I have no Port Forwarding enabled on my HH5 I can see port 8085 is open to the outside world.
Zenmap shows the following result:
8085/tcp open tcpwrapped
...
Firstly the port is showing that it has tcpwrapped like functions enabled on the application running behind that port. This means that it potentially has a host_access allow & deny file associated with it.
Therefore the application will only allow certain IP addresses to fully communicate and use the application.
It could be the TR-069 WAN management system or another BT service running a session on that port.