Browse Prior Art Database

Technique for Easing the Transitions to Logical Call Addressing

IP.com Disclosure Number: IPCOM000115020D
Original Publication Date: 1995-Mar-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 4 page(s) / 155K

Publishing Venue

IBM

Related People

Aldred, BK: AUTHOR [+3]

Abstract

Disclosed is a communication system in which users who have both logical and physical addresses can still make calls when only a physical address is known.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 35% of the total text.

Technique for Easing the Transitions to Logical Call Addressing

      Disclosed is a communication system in which users who have
both logical and physical addresses can still make calls when only a
physical address is known.

      Many communications systems, such as the conventional
telephone, associate users with the address of a physical device.
Address Books for such systems relate details about a user (a person
or business) to one or more physical addresses (telephone numbers)
and making a call only requires knowledge of the physical address.

      Some more complex systems associate users with a logical
address and provide means by which such logical addresses can be
associated with the address of a physical device.  In this case,
Address Books relate details about a user with their logical address
and also relate logical addresses to physical addresses.  In such a
system, making a call requires the specification of the logical
address to which a connection is required as well as the physical
address to which the connection request will initially be addressed.
In our implementation, the logical address is called a nodename and
it is desirable that such nodenames are globally unique if they are
to provide a guarantee that the proper connections are established.

      It should be clear that in such systems, it is possible for a
given logical address to be associated with several physical
addresses and for such associations to be dynamically changeable.
Equally a given physical address may support several logical
addresses, again dynamically changeable.  So that the receiver can
tell who an incoming call is intended for it will therefore contain
the logical address to which a connection is desired.  If this
matches the logical address of the receiver, it is assumed that the
call has found its destination, but where there is no such match, the
receiver can choose whether to accept, reject or redirect the call
based on the logical address.  This makes it very easy to set up call
redirection and screening mechanisms, establish gateways, routers and
switching nodes and various kinds of servers.

      As an example of how such a system operates, consider an
attempt by user A to call user B, for whom he has two pieces of
information:
  1.  081 948 XXXX (an ISDN telephone number - a PHYSICAL address)
  2.  ZENO         (a LAKES NODENAME - a LOGICAL address)

      When A places the call, his system dials the ISDN number.  When
contact is established, A's system passes the desired logical
address, "ZENO", to the receiving system.  That system can then
compare the string with its local logical address.  Several
possibilities can be imagined:
  o  the local logical address is ZENO and B is currently present.  B
      personally answers the call.
  o  the local logical address is ZENO but B is currently present.
He
      has instructed his machine to automatically answer calls and
  ...