In this report we present the design of the Autonomous Transport Protocol (ATP). The basic service provided by ATP is a reliable transport connection between two endpoints (identified by content identifiers) independent of their physical location. Autonomy allows dynamic endpoints relocation on different end hosts without disrupting the transport connection between them.

ATP depends on the existence of an underlying Instance-Based Network (IBN) to achieve its goals. An IBN provides the flexibility of having different instances of the same content. It is up to the user of the IBN network to define the relation between these instances. An IBN allows its user to to map a content to a particular node. Application endpoints can send messages to other content-identified endpoints. Routing in the IBN is instance-based;
the IBN can route a message to a specific content instance or to the nearest instance, if no exact match is found for the destination content instance.
Moreover, the IBN replicates the stored contents in order to provide fault tolerance and IBN nodes along the query path can cache a content to provide fast answers to future queries. The ATP layer in the intermediate nodes between the source and destination endpoints can actively participate in the connection, for example, to buffer data for the destination endpoints during periods of unavailability. Data is transferred by a combination of active and passive operations, where the ATP
layer of a node can decide whether to actively push the data to the destination or to passively wait for the destination endpoint to pull the data. The decision to whether to use the active or passive modes can be taken by a local policy on the node running the ATP protocol. (UMIACS-TR-2003-52)