Browse Prior Art Database

Network Control Unit

IP.com Disclosure Number: IPCOM000120615D
Original Publication Date: 1991-May-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 4 page(s) / 152K

Publishing Venue

IBM

Related People

Beavers, JA: AUTHOR [+4]

Abstract

This article describes a network control unit (NCU) which combines all of the features of bridging, network monitoring/management and a remodulating head end into a single system.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 49% of the total text.

Network Control Unit

      This article describes a network control unit (NCU) which
combines all of the features of bridging, network
monitoring/management and a remodulating head end into a single
system.

      Broadband local area networks (LANs) are frequency division
multiplexed networks that allow multiple LANs to coexist on the same
cable.  The topology of a broadband LAN is a tree with the head end
located at the root.  The head end incorporates the frequency
translation function which translates the inbound path frequency to
the outbound frequency.  There are two general types of head end
frequency translation:  limited function translation which simply
shifts the frequencies without demodulation/remodulation, and a
regenerative translator which demodulates the inbound signal to
baseband data, retimes the baseband data, then remodulates it to the
outbound frequency.  In multiple LAN environments, systems are used
to bridge separate networks together.  Traffic from one LAN to
another flows through the bridge, typically a dedicated CPU.  Other
CPUs distributed throughout the multiple LAN environment perform the
network monitoring and management functions.

      Some systems have three personal computer (PC) network
adapters, each one occupying a different channel pair. Because a PC
network is a broadband network, all three adapters can coexist on the
same coaxial cable such as many television channels coexist on the
same cable that comes into your home.  Therefore, three separate LANs
could be on the same cable by connecting different sets of computers
to each of the three channels.

      In implementing a medium to large LAN, or a multiple LAN, an
effective network would require additional features. First, each of
the three channel pairs requires its own frequency translating, or
remodulating, head end.  Second, one of the computers on each of the
three LANs (or a host system connected to each LAN) would have to be
a machine dedicated to provide the network management/monitoring func
tion.  Third, another machine would have to be dedicated to provide
the bridging function between the three channel pairs with the
machine having one of each of the three adapters installed.  Finally,
another machine for each of the three channel pairs would have to be
dedicated to provide a bridge to either another type of LAN, i.e.,
baseband, or, a remote connection via telecommunications link.  Each
of these features requires, for many LAN scenarios, a great deal of
planning, software, hardware, support, coordination, etc., that must
be dealt with by the end user.

      The solution disclosed herein combines all of the features of
bridging, network monitoring/management, and a remodulating head end
into a single system.  This system could even act as a workstation on
any, or all, of the LANs connected by the bridge.
     System Components
           System with keyboard and monitor,
         ...