Multiplex communications – Pathfinding or routing – Switching a message which includes an address header
Reexamination Certificate
1999-12-16
2004-03-16
Ton, Dang (Department: 2666)
Multiplex communications
Pathfinding or routing
Switching a message which includes an address header
C370S360000, C370S386000, C370S410000, C379S229000, C709S223000, C709S227000
Reexamination Certificate
active
06707820
ABSTRACT:
TECHNICAL FIELD
This application relates generally to virtual circuit networks, and more specifically to a system and method for dynamic channel management providing expansion capability to computer telephony based applications.
BACKGROUND
The use of intelligent telephony based applications is increasing in multi-node telecommunication systems. Existing multi-node telecommunication systems using intelligent applications, such as an Interactive Voice Response (IVR) unit, provide a variety of services to customers. An IVR unit used to make outbound calls and/or to receive inbound calls allows vendors to automatically provide customers with an advertising or maintenance message. A node on such a multi-node system may be a processor-based system, such as a Personal Computer (PC), or any other resource capable of storing information. Furthermore, each node in such a multi-node system may have an interface to allow connections to be established between the different nodes. Moreover, the IVR allows customers to make inbound calls into the multi-node system where different nodes may have different applications residing on them. When a customer calls into the multi-node system of the vendor, the IVR presents the customer with a set of options to choose from, and based on the choices the call may be routed to different nodes in the network. Thus, the different nodes generally need to communicate with each other to provide the desired services to the customer.
Existing systems, however, allow only a limited number of nodes to be connected together to form the multi-node system. Furthermore, the different nodes have to be physically collocated because of the length of the serial bus or cable that is used to connect the different nodes together. The number of nodes that could be connected to the cable is further limited to prevent impairment of the signal on the cable. Moreover, due to the nature of the interface and the associated physical limitations, the nodes in the network are daisy chained to each other. When a caller calls on a telephone line attached to one of the nodes requesting services resident on another node, the call is connected through to the remote node using the serial bus or cable.
More recently, connection-oriented networks have been used to connect different nodes in a multi-node network. A connection-oriented network is a network specifically designed to support connection-oriented protocols. In a connection-oriented protocol, two network nodes of a multi-node network interact with one another to set up a connection between the nodes. When a connection request is made to a connection-oriented network, the network establishes a path between the source and destination nodes. The nodes may then be configured to route packets of data along the established path. A packet switched network that is connection-oriented may also be referred to as a Virtual Circuit (VC) network. Asynchronous Transfer Mode (ATM) networks are an example of virtual circuit networks. ATM architecture allows multiple nodes to be connected together and provides a backbone for data and voice communications.
Asynchronous Transfer Mode is a broadband networking technology that provides a mechanism for transporting voice and data between systems within a virtual circuit network. ATM technology may be used for both Local Area Networks (LANs) and Wide Area Networks (WANs). Thus, ATM may be used to knit local and wide area networks and services into a seamless whole.
Presently available ATM networks include data links for interconnecting a plurality of network switches. A plurality of nodes (such as workstations, personal computers, etc.) are connected to the network switches by way of links. The links have an input port and an output port with respect to each node. When a certain node (“source node”) desires to communicate with another node (“destination node”), a routing for enabling the data transfer between them is selected and determined using identifiers. The topology uses switches that establish a logical circuit from the source node to the destination node, and may guarantee a quality of service (QOS) for that transmission. However, unlike telephone switches that dedicate circuits end to end, unused bandwidth in ATM's virtual circuits can be appropriated whenever available.
The ATM physical interface may be operated at 25.6, 155.52, or 622.08 MHZ full duplex. An ATM Network Interface Card (NIC) may be installed into each node, and connected to an ATM workgroup switch. The NIC provides the desired bridging between the ATM Network Interface and the internal PC Signal Computing System Architecture (SCSA) serial bus required to interface to other resource cards. Thus, connections could be established between the ATM Network Interface and the SCSA for call processing, call connectivity, etc. The SCSA is an internal bus used for interconnecting cards within a PC.
As previously discussed, ATM uses a connection-oriented packet switched protocol. The information to be communicated between the source and destination nodes is organized into a plurality of packets of fixed size. This fixed unit allows very fast switches to be built because the processing associated with variable-length packets is eliminated. For example, there is no need to process the packet to determine the end of the frame. Each packet has a fixed size of 53 bytes and comprises a header and an information field called the “payload”. The header is usually a 5-byte header and the size of the payload is 48 bytes. The payload field stores the information to be transferred, and the header stores a variety of other informations related to the packet that is desirable for the transfer of information. The small size of the ATM packet also ensures that voice and video can be inserted into the stream frequently enough for real-time transmission.
Each packet is part of a virtual circuit, which is identified by a Virtual Path Identifier (VPI) and a Virtual Channel Identifier (VCI) parameter stored within the packet header. A virtual circuit may be a unidirectional virtual trunk carrying data. Since a VC is unidirectional, one receive and one transmit VC must be set up to provide a bi-directional path. Once a VC path is configured between a source node and a destination node within an ATM switch, all routing and switching of packets between the source node and destination node is performed by programmed hardwired logic that no longer requires microprocessor intervention. For transferring packets internally between ports, ATM switches utilize high-speed buses operating in gigabit per second ranges.
There are two primary types of virtual circuits. A Switched Virtual Circuit (SVC) is a VC that is dynamically setup and torn down using the ATM User Network Interface (UNI) end point-to-end point signaling protocol. The UNI protocol utilizes source and destination address information, provided by the node initiating the SVC request, to identify the two nodes requiring a VC Connection (VCC) through the ATM switch and then resolves these addresses to physical ports on the switch. The ATM switch has internal VC routing tables. Thus, on receiving the source and destination address information, it assigns a VPI/VCI translation to its internal VC routing tables. It is not necessary to use the same VPI/VCI at both the source and the destination ports, though often this may be the case. In addition, the same VPI/VCI may be used for both receive and transmit VC at one end. The UNI protocol provides the VPI/VCI assignment to each end point. Once the UNI protocol has completed setting up the SVC, either end point may begin sending packets to the other end by using the near-end assigned VPI/VCI route. The ATM switch performs the translations and switches the packets between the ports according to the stored routing tables. Thus, setting up a SVC between the source and destination nodes is similar in some respects to making a phone call over the Public Switched Telephone Network (PSTN).
The second VC type is called a Permanent Virtual Circuit (PVC). A PVC is staticall
Arndt Richard Edwin
Corey Jerry Lee
Fulbright & Jaworski LLP
Hom Shick
Intervoice Limited Partnership
LandOfFree
Virtual circuit network dynamic channel management does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Virtual circuit network dynamic channel management, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Virtual circuit network dynamic channel management will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3207122