4. What is the name of the computer based EMMS that provides a common forum where users can check in at their convenience, post messages, actively exchange ideas and participate in ongoing discussions?
A. Gateways are assumed to know correct routes; hosts begin with minimal routing information and learn new routes from gateways.
B. Layered protocols are designed so that layer n at the destination receives exactly the same object sent by layer n at the source.
C. Application programs as well as all protocol software from the Internet layer upward use only IP addresses; the network interface layer handles physical addresses.