RFC 1070 (rfc1070) - Page 2 of 17
Use of the Internet as a subnetwork for experimentation with the OSI network layer
Alternative Format: Original Text Document
RFC 1070 Experimental OSI Net February 1989 internetworking requires a large, varied, and complex environment. While an implementor of the OSI protocols may of course test an implementation locally, few implementors have the resources to create a sufficiently large dynamic topology in which to test the protocols and implementations well. One way to create such an environment is to implement the OSI network layer protocols in the existing routers in an existing internetwork. This solution is likely to be disruptive due to the immature state of the OSI network layer protocols and implementations, coupled with the fact that a large set of routers would have to implement the OSI network layer in order to do realistic testing. This memo suggests a scenario that will make it easy for implementors to test with other implementors, exploiting the existing connectivity of the Internet without disturbing existing gateways. The method suggested is to treat the Internet as a subnetwork, hereinafter called the "IP subnet." We do this by encapsulating OSI connectionless network layer protocol (ISO 8473) packets in IP datagrams, where IP refers to the Internet network layer protocol, RFC 791. This encapsulation occurs only with packets travelling over the IP subnet to sites not reachable over a local area network. The intent is for implementations to use OSI network layer protocols directly over links locally, and to use the IP subnet as a link only when necessary to reach a site that is separated from the source by an IP gateway. While it is true that almost any system at a participating site may be reachable with IP, it is expected that experimenters will configure their systems so that a subset of their systems will consider themselves to be directly connected to the IP subnet for the purpose of testing the OSI network layer protocols or their implementations. The proposed scheme permits systems to change their topological relationship to the IP subnet at any time, also to change their behavior as an end system (ES), intermediate system (IS), or both at any time. This flexibility is necessary to test the dynamic adaptive properties of the routing exchange protocols. A variant of this scheme is proposed for implementors who do not have direct access to the IP layer in their systems. This variation uses the User Datagram Protocol over IP (UDP/IP) as the subnetwork. In this memo we will call the experiment based on the IP subnet EON, an acronym for "Experimental OSI-based Network". We will call the experiment based on the UDP/IP subnet EON-UDP. It is assumed that the reader is familiar with the OSI connectionless network layer and, in particular, with the following documents: Hagens, Hall, & Rose
