LAN interconnection via ATM satellite links for CAD applications: the UNOM experiment

An extensive technical trial of ATM technology was conducted in the second half of 1994, as a joint effort among the partners in UNOM, a project of the RACE program of the Commission of the European Communities. The trial was based on LAN interconnection over virtual paths established by ATM cross-connects at two separate sites of the microelectronics manufacturer SGS-Thomson linked by digital satellite transmission systems. Details of the experimental satellite equipment used are set out in this paper. A Reed-Solomon block coding scheme, adapted to ATM cell transfer, was added onto the bit stream to achieve high-quality, cost-effective ATM transmission links. This field trial represents one of the first examples of ATM transport over satellite links established through compact VSAT earth stations installed at the user´s premises. Trial users placed a strong emphasis on TCP-IP networking. Significant performance improvement in terms of transfer time was measured when using modified versions of kernel files and utilities providing enhancements to the basic TCP protocol as recommended in the Internet RFC 1323. This trial has explicitly validated the use of ATM satellite links based on VSATs, e.g. for B-ISDN user access and corporate networks. It has demonstrated that high-quality links are achievable with low-cost, compact earth stations and highlighted the fact that simple adjustments to the user´s equipment prevent inadequate behavior of some communication protocols from compromising the efficient use of these links for data and multimedia business services