There has been a lot of discussion about "network neutrality" as being a core property of internet service. This discussion includes a number of inter-related concepts, which not every advocate agrees to. In particular, the wikipedia article on the subject identifies:
"* Non-discrimination means that all traffic over the network (typically or exclusively digital packets or bits) is treated the same by the network, including the traffic originating with the network operator. This principle of 'bit parity' means that all bits are treated as 'just bits', and no bit traffic is prioritized over other bits, and none is hampered or disabled.
* Interconnection means that network operators have both a duty of interconnection and a right of interconnection to any other network operator. Networks must be constructed so that there are a reasonable number of accessible interconnect points; that traffic is carried to and from rival networks at reasonable rates; and that the network is built with sufficient excess capacity to accomodate the reasonably foreseeable traffic that may be presented at the head-ends or peering points. Without a right of interconnection, there is no network.
* Access means that any end user can connect to any other end-user. End users may be people, but the term could also mean devices (modems, routers, switches) or even other networks. Access means that a piece of content, say, an email message, has a right to enter the network, and if properly addressed, be received by the other end user, even if said user is on another network. In other words, traffic can begin at any point on the network and be delivered to any other point."