Browse Prior Art Database

Connectionless Directory Services

IP.com Disclosure Number: IPCOM000117110D
Original Publication Date: 1995-Dec-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 4 page(s) / 231K

Publishing Venue

IBM

Related People

Giroir, D: AUTHOR [+2]

Abstract

Disclosed is a mechanism that connectionless access agents can use to maintain an acceptable end-to-end quality of service (by suppressing searches across the NBBS sub-network to locate destination connectionless access agents). Without such a mechanism, a search maybe necessary to locate a target connectionless access agent across the NBBS network which owns the resources to which the IP datagram is directed. Additionally, a path from the source resource to the target resource should be made available, whether a reserved network connection is used or a non-reserved one.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 25% of the total text.

Connectionless Directory Services

      Disclosed is a mechanism that connectionless access agents
can use to maintain an acceptable end-to-end quality of service (by
suppressing searches across the NBBS sub-network to locate
destination connectionless access agents).  Without such a mechanism,
a search maybe necessary to locate a target connectionless access
agent across the NBBS network which owns the resources to which the
IP datagram is directed.  Additionally, a path from the source
resource to the target resource should be made available, whether a
reserved network connection is used or a non-reserved one.  The time
needed for the search added to the time required to obtain a path
increases the processing delay seen by the datagram such that the
datagram may no longer useable (an example would be the transporting
of SMDS datagrams that have a maximum delay under which they should
be delivered to their final destination).  The mechanism disclosed
here allows to suppress these searches by pre-loading local caches
and allow the pre-establishment of the paths needed for
communication, thus reducing the delay required to route a datagram.

      This document proposes a set of mechanisms that connectionless
access agents for Networking BroadBand Services (NBBS) can use to
obtain a level of service adapted for connectionless protocols.
Examples of connectionless access agents are IP (from the famous
TCP/IP protocol suite) and SMDS - Switched Multimegabit Data Services
(CBDS - Connectionless Broadband Data Services in Europe).

      Connectionless access agents exchange datagrams across the NBBS
backbone.  These datagrams are sent/received from/to equipment
outside of the backbone.  A datagram is a variable length message
containing the address of the terminating equipment, destination of
the message.  The type of the address in the datagram is protocol
dependent, possible examples are IP host addresses for an IP access
agent or E.164 addresses for an SMDS/CBDS access agent.  To insure an
acceptable end-to-end quality of service,the access agent cannot the
access agent cannot afford delaying too much the transmission of the
datagram.  Two major contributors to delays are:  the searches across
the NBBS network, to locate the destination access agent taking care
of the terminating equipment whose address is specified in the
datagram, the establishment of a communication path to the
destination node.  A communication path consists in an ANR string in
case of non-reserved network connections or consists in a network
connection handle if reserved network connections are used.  To avoid
these unacceptable delays, this document proposes a specific
protocol, adapted to connectionless access services, based on
existing NBBS mechanisms.  This protocol prepares the necessary
information and mechanisms that a connectionless access agent needs,
in order to forward datagrams toward their final destination, without
requiring a netw...