Technical data

JSC 36381 MARCH 30, 2000

Baseline

1 Overview

The OPS LAN Interface Control Document describes the architecture, operation and

management of the ISS operations laptop computer network. The OPS LAN is capable

of facilitating routine electronic data processing tasks, such as data transfer / storage,

procedure viewing, electronic mail (e-mail) and general office automation.

1.1 Topology

The OPS LAN uses a multipoint Ethernet bus topology for network communications. It

implements both the IEEE 802.3 (Standard Ethernet) and 802.11 (Radio Frequency)

connectivity standards. Prior to the arrival and installation of the U.S. Lab Coax

Ethernet at Mission 5A, network communication is restricted solely to RF.

Refer to the S-POCCB Manifest and Usage web page (see Appendix B.4) for details

about the OPS LAN topology for upcoming missions.

1.2 Networking Protocols

Networking protocols are collections of rules and procedures governing

communication among the computers and network devices (nodes) of the network. The

SSC OPS LAN utilizes NetBEUI and TCP/IP, as supplied by Microsoft, for network

communication protocols.

1.2.1 NetBEUI

NetBEUI (NetBIOS Extended User Interface) is a very fast but nonroutable protocol,

usually used on Microsoft networks. It is Microsoft’s extension of IBM’s NetBIOS

protocol standard. NetBEUI is self-tuning and self-configuring, and it is suitable for

small Local Area Networks, such as the OPS LAN. The NetBEUI protocol uses

NetBIOS broadcasts to locate other computers on the network; computers that are

not on the physical network (i.e., that require a router to reach), or that do not have a

NetBIOS name, are not accessible via NetBEUI.

1.2.2 TCP/IP

TCP/IP (Transmission Control Protocol / Internet Protocol) is the most common

network protocol in the world, and it is the current default protocol Windows NT

uses to connect to other systems. TCP/IP is a routable protocol; that is, a computer

need not be located on the local physical network to be accessed. Each OPS LAN

node is assigned a unique address, which is called the node’s IP address. Chapter 2

provides details about the network’s IP address scheme.

Chapter