Browse Prior Art Database

Multiplexing Local Area Network Emulation Data Direct Virtual Circuit Connections Between IBM Forwarding Engines

IP.com Disclosure Number: IPCOM000117881D
Original Publication Date: 1996-Jul-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 4 page(s) / 102K

Publishing Venue

IBM

Related People

Cheng, Y: AUTHOR

Abstract

Disclosed is a method to multiplex Local Area Network (LAN) Emulation Data Direct Virtual Circuit Connections (VCCs) between IBM Forwarding Engines (FEs) so that all the LAN Emulation Clients (LECs) on any two FEs can share a single Data Direct VCC instead of having one VCC for each LEC as required by the LAN Emulation Specification Version 1.0.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Multiplexing Local Area Network Emulation Data Direct Virtual Circuit
Connections Between IBM Forwarding Engines

      Disclosed is a method to multiplex Local Area Network (LAN)
Emulation Data Direct Virtual Circuit Connections (VCCs) between IBM
Forwarding Engines (FEs) so that all the LAN Emulation Clients (LECs)
on any two FEs can share a single Data Direct VCC instead of having
one VCC for each LEC as required by the LAN Emulation Specification
Version 1.0.

      To multiplex data frames only onto VCCs between IBM FEs, a FE
must know if the VCC is connected to another FE.  A FE-ID is
introduced and will be used by FEs to distinguash themself from other
non-FE devices.

Assigning An Unique FE-ID to each FE

      Since data must not be multiplexed onto VCCs connected to a
non-FE Asynchronous Transfer Mode (ATM) address, a FE must decide if
a destination ATM address is multiplexable by checking if it is a FE.
Therefore, an unique FE-ID must be assigned to each FE.  One way to
guarantee the uniqueness of the FE-ID is to use the FE's burned-in
MAC address as its FE-ID.

FE-ID Registration

      Each LEC on a FE must know its FE-ID before joining the ELAN,
and when joining the ELAN by issing the LE_JOIN_REQUEST frame to a
LAN Emulation Server (LES) on a NCE (Network Control Engine), it must
also register its FE-ID with the LES.  When the LES receives the
LE_JOIN_REQUESTframe, it must associate the FE-ID with the
SOURCE-ATM-ADDRESS specified in the request frame.  A zero FE-ID must
be assigne a non-FE SOURCE-ATM-ADDRESS and each ATM address in the
mapping table must be associated with a FE-ID.

FE-ID Resolution

      The way that FEs resolve each other's FE-IDs is through the
same LE_ARP protocol defined by the ATM Forum LANEv1.0 standard,
except that the FE-ID information will be passed along in the
LE_ARP_RESPONSE frame.  When a LEC on a FE LE_ARPs, it sends out a
LE_ARP_REQUEST frame to a LES in the network.  When a LES on a NCE
receives the LE_ARP_REQUEST frame whose TARGET-LAN-DESTINATION
matches with a LAN-DESTINATION in its table, it must respond with
both the TARGET-ATM-ADDRESS and the FE-ID of the LAN-DESTINATION in
the LE_ARP_RESPONSE frame.  Or when a LEC on a F receives the
LE_ARP_REQUEST frame whose TARGET-LAN-DESTIANTION matches with its
own LA...