Of course it doesn't have to be a piece of software, MSP Client could be the client that is using MSP.
But what is this software? Is it something that is intalled as a protocol or service on a network adapter, and intercepts all traffic destined for the internet and transparently routes it through a a proxy server - but first using the Windows credentials of the user making the TCP request to see if they're allowed to use the internet?
My real question comes down to: how is Microsoft Proxy able to know who i am, based on a TCP socket open request? i.e. if i try to connect to a TCP server, Proxy is able to inject itself between, and know who am. Then my attempts to make a TCP sockets connection, e.g.:
>telnet torrent.consonto.com 6881
can succeed or fail depending if i am allowed access.
My confusion comes from the fact that a TCP socket connect doesn't contain any NT identification information. How is Windows able to know it's "me"?