ABSTRACT
This chapter presents the Delay- and Disruption-Tolerant Networking (DTN) architecture as proposed by RFC 4838. It describes the DTN architecture in a general way addressing both interplanetary and earth-bound scenarios. It also presents the Bundle Protocol as defined in RFC 5050. The chapter introduces DTN basic concepts and terminology, and provides a brief description of the Internet architecture. It illustrates that the Internet's network architecture is based on the layered system design principles and uses the Transmission Control Protocol/Internet Protocol protocol stack. DTN uses the store-carry-and-forward mechanism to withstand intermittent connectivity by overlaying a new protocol layer named "bundle layer" which enables the DTN node to transmit messages which are called "bundles". The DTN architecture implements through the bundle layer a new transmission protocol, called Bundle Protocol. The extension blocks are all blocks other than the primary and payload blocks. The Bundle Protocol permits both proactive and reactive bundle fragmentation.
