Tau: Transport and up
Version 0.3 protocol specification


This document specifies Tau, a nonlayered framework for composing end-to-end protocol functions such as error control, congestion avoidance and control, and security. Tau provides generic multiplexing and composition mechanisms for that enable end-to-end protocol mechanisms to be efficiently combined to form new services. Tau supports a sockets/TLI-like interface as well as a more general ALF-type API. The Tau specification comprises the following parts:

1. Motivation and Design Philosophy
This section describes the problem that Tau is intended to solve, as well as some architectural objectives for the solution and how they relate to the elements of Tau.

2. Tau's Model of Operation
This section describes the environment in which Tau is intended to operate, including the services it expects from lower layers and the interfaces it presents to applications. Tau's basic packet processing method is also outlined in this section.

3. Protocol Function Interface
Tau defines a specific API for interaction with individual protocol functions such as connection management and error detection; this interface varies depending upon the protocol function. This section defines the four classes of protocol functions (forward data-touching, forward control, backward control, and other), and specifies the methods that make of the interface for each.

4. Metaheader Specification
The Tau metaheader supports the (only) functions provided by the Tau framework itself, namely multiplexing and protocol composition. This section specifies the (only) "bits on the wire" defined by Tau itself and defines the basic requirements for interoperability between Tau implementations.

5. References