IBM 360/370 Implementation of the Internet and TCP Protocols -- Design Specifications

摘要

A family of internet host-to-host protocols has recently been defined to allow computer communications across interconnected packet networks with diverse properties. This interact protocol family is defined in two distinct levels. The lower level, Internetwork Protocol or IP, provides simple datagram service. Transmission Control Protocol or TCP is a higher-level internet protocol that ses IP for data transport. TCP provides connections, strong end-to-end control, flow control, and a form of out-of-band signalling. The IP/TCP combination is intended to be the successor to the original ARPANET Host-to-Host Protocol (AHHP). Under ARPA contract, UCLA has implemented Version 4 of the IP and TCP protocols for an IBM 360/370 host computer on the ARPANET. This implementation is integrated into the existing Network Control Program for AHHP, and was designed to be compatible at the system-call interface so that existing user-level protocol programs can be used interchangeably with AHHP and IP/TCP. The implementation is layered to match the protocols. This document gives a technical overview of the UCLA IP/TCP implementation. It describes the NCP software environment, the resolution of compatibility issues, and the design of both the IP and TCP layers.