Licklider Transmission Protocol - Extensions
In an Interplanetary Internet setting deploying the Bundling protocol being developed by the Delay Tolerant Networking Research Group, the Licklider Transmission Protocol (LTP), is intended to serve as a reliable convergence layer over single hop deep-space RF links. LTP does ARQ of data transmissions by soliciting selective-acknowledgment reception reports. It is stateful and has no negotiation or handshakes. LTP is designed to provide retransmission-based reliability over links characterized by extremely long message round-trip times (RTTs) and/or frequent interruptions in connectivity. Since communication across interplanetary space is the most prominent example of this sort of environment, LTP is principally aimed at supporting "long- haul" reliable transmission in interplanetary space, but has applications in other environments as well. This document describes extensions to LTP, and is part of a series of related documents describing LTP. Other documents in this series cover the motivation for LTP and the main protocol specification. We recommend reading all the documents in the series before writing code based on this document. This document is a product of the Delay Tolerant Networking Research Group and has been reviewed by that group. No objections to its publication as an RFC were raised.