Chapter 5. Network Layer Mobility

As discussed in Chapter 2, “Internet Sessions,” Layer 3 (the Internet, or network layer) is responsible for the transmission of datagrams from source to destination. The network layer is responsible for routing functions and fragmentation/reassembly while maintaining any quality of service (QoS) required by the transport layer. This section provides a brief overview of the network layer to illustrate the challenges that arise because of mobility.

The Internet Protocol (IP) is the most commonly known example of a Layer 3 protocol, and it provides the foundation upon which the Internet itself was built. IP is responsible for connectionless transfer of packets from an end node, through a network, to another end ...

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