phamminhtuan
27-10-2008, 10:52 PM
The application layer corresponds to the OSI session, presentation, and application layers. Although some routing protocols such as Border Gateway Protocol (BGP) and routing Information Protocol (RIP) reside at this layer,[2] (http://vnpro.org/forum/#ch01fn02) the most common services of the application layer provide the interfaces by which user applications access the network.
[2] BGP is an application layer protocol because it uses TCP to transport its messages, and RIP because it uses UDP for the same purposes. Other routing protocols such as OSPF are said to operate at the internet layer because they encapsulate their messages directly into IP packets.
[2] BGP is an application layer protocol because it uses TCP to transport its messages, and RIP because it uses UDP for the same purposes. Other routing protocols such as OSPF are said to operate at the internet layer because they encapsulate their messages directly into IP packets.