Method and apparatus providing connection-oriented services for packet switched data communications networks. Directory services include distributed discovery of MAC addresses and protocol alias addresses. Topology services include a link state topology exchange among switches, which provides each switch with a complete topology graph of the network. This enables an access switch receiving a data packet to determine a complete path from a source end system to a destination end system. Another service includes resolution of broadcast frames to unicast frames, in order to reduce the amount of broadcast traffic. Policy restrictions may be applied prior to connection setup. Path determination services enable multiple paths from a source to a destination. Connection management includes source routed mapping of connections on the desired path. A distributed call rerouting service is provided wherein if a link on an active path fails, each switch receives a topology change notification and unmaps any connection involving the failed link. A broadcast/unknown service provides restricted flooding of nonresolvable packets. Furthermore, connection-oriented switching is provided based on the source and destination MAC addresses as a connection identifier. Still further, resolution of networks outside the switch domain is enabled by access switches listening for network and server route advertisements and maintaining best routes to said networks and servers. The best route metrics may be combined with best path metrics to determine a path from a first access switch to an egress switch connected to the external network.

Distributed connection-oriented services for switched communication networks

Method and apparatus for establishing restricted broadcast groups in a switched network. The method assigns different virtual LAN identifiers (VLAN-IDs) to different subsets of associated end systems or access ports. Tables are maintained for mapping the VLAN-IDs with associated end systems and access ports. When a broadcast packet is received at a first switch, it is encapsulated with a VLAN header, including the VLAN-IDs, and sent out a multicast channel to all other switches in the network (domain). The original packet is sent out the other access ports of the receiving switch for the designated VLAN-IDs. The switches receiving the VLAN packet remove the header and send the original packet out access ports associated with the VLAN-IDs extracted from the header. The method provides a mechanism for forwarding broadcast packets of a protocol not supported by the switching mechanism, as well as multicast packets and unicast packets from undiscovered end systems.

Method for establishing restricted broadcast groups in a switched network

A local area network switch which implements packet segmentation and reassembly for cell-based switching on a backplane cell bus. A plurality of packet processing units are each coupled to a backplane cell bus wherein each packet processing unit hosts a plurality of local area network ports. Each packet processing unit is associated with a single packet buffer memory that is shared by the ports associated with the packet processing unit. The segmentation of local area network packets into fixed-size cells facilitates an efficient local area network switch which provides dedicated bandwidth for each of the ports associated with the switch. There is also provision for coupling the local area network ports to communicate with a high-speed network interface.

Method and apparatus for switching data packets in a data network

Flight of the Falcon

A method for integrating Asynchronous Transfer Mode (ATM) and frame-based traffic flows within a telecommunications network is disclosed. The telecommunications network includes a network processor having upside processing means for delivering an incoming flow from the telecommunications network to a switch and downside processing means for delivering outgoing network traffic from the switch to the telecommunications network. The incoming flow is initially received at the upside processing means as a frame-based flow. The incoming flow may be characterized as belonging to a group having frame-based flows and ATM flows. In response to the receipt of the incoming flow, the incoming flow is determined if it is destined for a legacy, ATM-only device. The incoming flow is then processed according to the determined routing requirements and the incoming flow characterization before delivering the incoming flow to the switch.

Network processor for multiprotocol data flows

Internetworking of FDDI, Ethernet or other local area networks including the ATM-LAN to the public ATM networks will involve the development of the ATM hub. Taking the performance and cost-effective factors into account, a scalable two-stage switching hub platform is proposed for private network environment with ATM-ready capabilities. Packet as well as cell switching architectures are adopted for the design of the switching fabrics. The architecture applies the concept of each source/destination port pair with dedicated input and output queues. A generalized multisubsystem interconnect adapter (MIA) is also proposed for heterogeneous subsystems to a common switching fabric. The design complexity versus performance of the I/O queues' number and length are analyzed. Finally, an implementation-leading approach of the MIA is presented.

http://ieeexplore.ieee.org/iel2/3878/11300/00513425.pdf

Yao-Tzung Wang

Papers

A platform for seamless interworking among conventional LANs and ATM networks