Browse Prior Art Database

V35 Smart Switch

IP.com Disclosure Number: IPCOM000117306D
Original Publication Date: 1996-Feb-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 4 page(s) / 66K

Publishing Venue

IBM

Related People

Benayoun, A: AUTHOR [+3]

Abstract

Up to now, if it were desirable to install a back up channel on an existing network, it was necessary to connect an other communication element: DCE2 in parallel of the DCE1 and when the NETWORK LINE 1 was broken, manually the operator had to set the new connection and start the routed communication.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 82% of the total text.

V35 Smart Switch

      Up to now, if it were desirable to install a back up channel on
an existing network, it was necessary to connect an other
communication element: DCE2 in parallel of the DCE1 and when the
NETWORK LINE 1 was broken, manually the operator had to set the new
connection and start the routed communication.

      This solution is huge and slow.  More than this, this approach
needs an operator present to check very often the status of the link.

      In some cases, automatic functions can activate the backup link
(CLIST on NETWIEW) but the cost is high as two separate interfaces
are required.

With the V35 SMARTSWITCH, it is now possible to set automatically a
backward communication line.  The process is based upon a state
machine analyzing all the states of the DTR and DSR leads of the V35
link between the DTE and DCE1 in order to detect an eventual break.
When a break is detected (DSR1 off), then all the leads of the
previous communication: DTR1,DSR1,RXD1,TXD1 and CLK1 are
automatically switched to DTR2,DSR2,RXD2,TXD2 and CLK2.

With DCE2 already configured similarly to DCE1, the connection is set
again.

      At the beginning, there is no communication so, DTR = 0 and DSR
= 0.  When DTE wants to set the communication, it set DTR =1.  DCE1
receives this signal on DSR1 and responds DTR1 =1, received by DTE on
DSR.  At this time DTE can send the data on TDX and receive on RXD.
If a problem occurs on DCE1 side, DTR1 = 0 so, DTE receives D...