Accession Number:

ADA055996

Title:

Specifications for the Interconnection of a Host and an IMP (Interface Message Processor).

Descriptive Note:

Corporate Author:

BOLT BERANEK AND NEWMAN INC CAMBRIDGE MASS

Personal Author(s):

Report Date:

1978-05-01

Pagination or Media Count:

231.0

Abstract:

The ARPA computer network permits large, dissimilar, geographically separated computers, called Hosts, to communicate with each other. One or more Hosts can be connected to a local Interface Message imp, which transmits messages from its Hosts to other Hosts and accepts messages for its Hosts from other Hosts. There need be no direct communication circuit between a given pair of Hosts in such cases intermediate IMPs act as message switchers. The message switching is performed as a store and forward operation. The Terminal IMP TIP, which consists of an IMP and a Multi-Line Controller MLC, extends the network concepts by permitting the direct attachment without an intervening Host of up to 63 dissimilar terminal devices to the network. This document provides detailed specifications of the electrical and logical characteristics of the interface which a Host must provide for attachment to an IMP or TIP. In addition, it specifies the formats of message which a Host may send across this interface into the network or which the Host must be prepared to receive from the network. These messages may be directed tofrom other Hosts, the local IMP, or under certain conditions programs which monitor the network performance at any IMP. Author

Descriptors:

• *DATA TRANSMISSION SYSTEMS
• *NETWORKS
• *COMPUTERS
• *MESSAGE PROCESSING
• *DIGITAL COMPUTERS
• REAL TIME
• SPECIFICATIONS
• INTERFACES
• COMPATIBILITY
• MODULAR CONSTRUCTION
• MODEMS
• TIME SHARING

Subject Categories:

• Computer Hardware
• Computer Systems
• Non-Radio Communications

Distribution Statement:

APPROVED FOR PUBLIC RELEASE