Network Working Group D. Estrin Request for Comments: 1940 USC Category: Informational T. Li Y. Rekhter cisco Systems K. Varadhan D. Zappala USC May 1996 Source Demand Routing: Packet Format and Forwarding Specification (Version 1). Status of this Memo This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind. Distribution of this memo is unlimited. 1. Overview The purpose of SDRP is to support source-initiated selection of routes to complement the route selection provided by existing routing protocols for both inter-domain and intra-domain routes. This document refers to such source-initiated routes as "SDRP routes". This document describes the packet format and forwarding procedure for SDRP. It also describes procedures for ascertaining feasibility of SDRP routes. Other components not described here are routing information distribution and route computation. This portion of the protocol may initially be used with manually configured routes. The same packet format and processing will be usable with dynamic route information distribution and computation methods under development. The packet forwarding protocol specified here makes minimal assumptions about the distribution and acquisition of routing information needed to construct the SDRP routes. These minimal assumptions are believed to be sufficient for the existing Internet. Future components of the SDRP protocol will extend capabilities in this area and others in a largely backward-compatible manner. This version of the packet forwarding protocol sends all packets with the complete SDRP route in the SDRP header. Future versions will address route setup and other enhancements and optimizations. Estrin, et al Informational