On Tue, 14 Apr 1998, Rici Lake wrote:
> -- transport protocols (such as PPP and Ethernet) which are only relevant
> to the particular machines on that link,
Srictly speaking PPP and Ethernet (MAC+LLC) are data link protocols not
transport protocols (to adher to standard terms).
> -- network protocols (IP, TCP, UDP, etc.) which, generally speaking, must
> be adhered by all machines ("hosts") on the internet, and
IP is a network layer protocol which sits on hosts and routers. However,
TCP and UDP are tranport layer protocols. TCP and UDP are not required
inside the network (on the routers), they only need to be implemented at end
machines (hosts). Router is a layer 3 (network layer) device.