Browse Prior Art Database

Universal Solution for X.25 Initializing Technique

IP.com Disclosure Number: IPCOM000043567D
Original Publication Date: 1984-Sep-01
Included in the Prior Art Database: 2005-Feb-05
Document File: 2 page(s) / 74K

Publishing Venue

IBM

Related People

Gillooly, BM: AUTHOR

Abstract

This article describes a link initialization technique that allows a data terminal equipment (DTE) to attach to a network which uses a layered protocol such as the X.25 protocol. The link initialization procedure includes a wait loop which handles received interrupts which may occur during the waiting period. If no interrupt occurs during the waiting period, the procedure takes the initiative to initialize the link and, as a result, the DTE is interconnected to the network. The X.25 interface protocol requires that a DTE should always take the initiative in establishing a link between the network and the DTE. The protocol requires that the DTE issue an SABM (said asynchronous balance mode) command with a poll bit on.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 67% of the total text.

Page 1 of 2

Universal Solution for X.25 Initializing Technique

This article describes a link initialization technique that allows a data terminal equipment (DTE) to attach to a network which uses a layered protocol such as the X.25 protocol. The link initialization procedure includes a wait loop which handles received interrupts which may occur during the waiting period. If no interrupt occurs during the waiting period, the procedure takes the initiative to initialize the link and, as a result, the DTE is interconnected to the network. The
X.25 interface protocol requires that a DTE should always take the initiative in establishing a link between the network and the DTE. The protocol requires that the DTE issue an SABM (said asynchronous balance mode) command with a poll bit on. On receiving this command, the DCE (data communication equipment) of the network issues a UA (unnumbered acknowledge) response to the command. The link layer of the DTE notifies the upper layer, and data is transferred from the DTE to the network. Many of the networks which have been implemented around the world are already polling the DTE when it is powered on. This causes various initialization problems for the DTEs. For example, some networks poll with the SABM commands and some with disconnect (DISC) commands and others with DM (disconnect mode) with the final bit equaling 0. This article provides a universal technique which enables a DTE to interconnect to any type of network. The initialization...