Browse Prior Art Database

Local Area Network Protocol for Autonomous Control of Attached Devices

IP.com Disclosure Number: IPCOM000101256D
Original Publication Date: 1990-Jul-01
Included in the Prior Art Database: 2005-Mar-16
Document File: 7 page(s) / 271K

Publishing Venue

IBM

Related People

Brann, JJ: AUTHOR [+2]

Abstract

Local Area Networks (LANs) are composed of electrical or optical technology information transmission media, LAN adapters, and attached host devices which "host" system application functions. The LAN adapter is the hardware that enables the host device to share the communications media. Our definition of a network includes those communication services, usually provided by software, which have become associated with the Session Layer of the International Standards Organization's (ISO) Open System Interconnection (OSI) Reference model. The software that provides this "session-like" service is called the Network Operating System (NOS). In some systems the NOS software is resident in the host device; however, for the Real Time Communications Network the NOS resides in the LAN adapter.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 18% of the total text.

Local Area Network Protocol for Autonomous Control of Attached Devices

       Local Area Networks (LANs) are composed of electrical or
optical technology information transmission media, LAN adapters, and
attached host devices which "host" system application functions.  The
LAN adapter is the hardware that enables the host device to share the
communications media. Our definition of a network includes those
communication services, usually provided by software, which have
become associated with the Session Layer of the International
Standards Organization's (ISO) Open System Interconnection (OSI)
Reference model.  The software that provides this "session-like"
service is called the Network Operating System (NOS).  In some
systems the NOS software is resident in the host device; however, for
the Real Time Communications Network the NOS resides in the LAN
adapter.

      Host devices are generally sequential processing computers with
resident application software.  When this is true, the host device is
capable of initiating data flow on the LAN in and out of its own
memory.  When the host device has no sequential processing
capability, such as processor-less devices like printers, parallel
processors like signal processing engines, or sequential processing
computers with uninitialized RAM and no ROM, the host device is not
capable of initiating LAN-based communications.  This type of device
will be called a "Slave Device."  (An uninitialized sequential
processor is a Slave Device until it has been initialized with
software and then it is no longer a Slave Device.)

      Very few existing networks directly address the problem of how
to allow Slave Devices to participate in peer-to-peer communications
on the network.  Of the networks that do address the problem, the
popular solution is to require that a sequential processor be added
to the Slave Device to provide this control function.  Some networks
have addressed this problem by allowing application software to be
downloaded to and executed in the LAN adapter processor concurrent
with the resident NOS software.  This concurrency presents a severe
integration and test problem as each application-specific download
requires independent testing.

      The services and protocols presented in this article provide a
unique communication capability for the autonomous control of the
Slave Devices without requiring the download of application-specific
code into the LAN adapter, nor the addition of a sequential
processor.  The basic approach is to standardize the representation
of all Slave Device interfaces as if each device was a separate
memory.  The LAN treats all Slave Devices as memory, thereby keeping
the LAN functions the same for all such devices.  All slave
functionality must be initiated and fed parameters through the memory
mapped interface.

      Detailed Description: The device memory operation service
requests are called the Device Control Services (DCS) o...