Match the following phrases with their correct definitions: 1: Autonomous system 2: Encapsulation 3: Internetworking匹配题

A large network managed by a single administrative domain

A company that charges fees for servicing computers and communication equipment

Internal networks within an organisation

Interconnection of multiple different layer 2 networks, not necessarily of the same type, using an additional protocol layer

The process of adding headers (and possibly trailers) to a protocol data unit passed down from a higher layer

The process of removing headers (and possibly trailers) from a protocol data unit passed up from a lower layer