3Com Corporation

Lior Katzri

Benny Gershon

Sarit Shani Natanson

Opher Yaron

Ronit Aizicovich

Dror Goldstein

Yuri Shwartsburd

A method of notification and handling of device status changes in MPOA enabled ATM based networks. In a first method notification of changes in device status configuration are provided by selectively releasing one or more Data Direct VCs that were previously established be LECs connecting MPOA Servers and MPOA Clients. An MPOA Server, upon detecting a change to its device configuration status, releases the Data Direct VCs connecting its associated LEC to known MPSs and MPCs that are neighbors to it. All MPOA devices for which a Data Direct VC was released delete all LE_ARP cache entries associated with the ATM destination of the released Data Direct VC. In a second method, each MPOA device periodically sends keep alive messages as targetless LE_ARP messages having a time to live TLV appended. An MPOA device receiving the keep alive message, refreshes (i.e., restarts) a validation timer for each association made by the corresponding MPOA identification TLV. If the validation timer expires before being refreshed, the MPOA device deletes all associations previously made by the corresponding MPOA identification TLV.

Method of MPOA status change notification

An apparatus for and a method of extending the ATM Forum LAN Emulation standard to support 802.1Q VLAN tagging with Independent VLAN Learning. A standard LEC entity is modified to perform the VLAN tagging method that supports Independent VLAN Learning. Since the LES may also respond to LE_ARP messages, it is optionally modified to perform the VLAN tagging method of the invention so as to provide support for 802.1Q Independent VLAN Learning. Support for 802.1Q Independent VLAN Learning is provided by adding a VLAN-ID TLV to LAN Emulation control messages such as LE_ARP and LE_REGISTER messages. The TLV added comprises the VLAN Tag Header information that is normally carried by the Ethernet frame in 802.1Q networks.

Apparatus for and method for supporting 802.1Q VLAN tagging with independent VLAN learning in LAN emulation networks

A method of controlling the route used for a flow in an environment comprising a default routing path and a shortcut path in an MPOA enabled ATM based network. A data field is added to the Ingress Cache table in the Ingress MPOA Client (I-MPC) to indicate whether the flow is to be routed through an MPOA shortcut towards the Egress MPOA Client (E-MPC) or is to be routed through the default path towards the Ingress MPOA Server (I-MPS). A first embodiment comprises a method of controlling the routing of a data flow from a source to a destination for security purposes. A second embodiment comprises a method of load sharing a plurality of data flows. A third embodiment comprises a method of learning about past MPOA resolution successes and failures and utilizing past establishment history to bypass the MPOA resolution process.

Method of establishing a flow in an ATM based MPOA network

A method of establishing calls between an ingress MPC (the calling party) and an egress MPC (the called party) in MPOA enabled ATM based networks. The call establishment method utilizes the call request SETUP, CONNECT and CONNECT_ACK messages in creating the shortcut VCC between ingress and egress MPCs. The calling party is adapted to send a READY_IND message in a reliable manner to the called party indicating that it is ready to receive frames over the shortcut VCC. The called party starts sending data over the shortcut VCC only when it knows that the calling party is ready. The called party knows the calling party is ready upon receipt of a READY_IND message or at least one data frame on the shortcut VCC. The calling party knows that the called party is ready to receive frames when it receives the CONNECT message. Since the READY_IND message sent by the calling party may get lost, the calling party is adapted to re-send the READY_IND message repeatedly until it is certain the called party has received it. The calling party utilizes a timer whereupon expiration, the READY_IND message is re-sent to the called party and the timer is restarted.

Method of establishing MPOA shortcut virtual channel connections

An apparatus for and a method of implementing multicast registration in an ATM based ELAN. The present invention provides a mechanism for a LEC to register to receive all multicast group traffic flows without requiring the LEC to generate a separate request for each multicast MAC address. The mechanism of the present invention provides means for a LEC to register to receive all multicast flows by defining an 'all_multicast' TLV and including this TLV in the LE_REGISTER_REQUEST request message sent by the LEC. The LEC, LES and SMS are modified to perform the multicast registration/unregistration method of the present invention. The LEC generates the LE_REGISTER_REQUEST message and includes the all_multicast TLV indicating that the LEC desires to receive all multicast traffic flows in the ELAN. The LES, upon receipt of such an all_multicast TLV, adds the LEC to its list of LECs to receive all multicast traffic and communicates the related information to the SMS. The SMS is adapted to add the LEC to each of the multicast groups currently maintained by the SMS. A similar symmetric process occurs in the event a LEC wishes to stop receiving all multicast traffic.

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Givaataim, Israel

Lior Katzri