Distributed connection-oriented services for switched communication networks

• US 20050083949A1
• Filed: 03/01/2004
• Published: 04/21/2005
• Est. Priority Date: 11/15/1995
• Status: Active Grant

• Current Assignee: Extreme Networks, Inc.
• Original Assignee: Enterasys Networks Incorporated (Extreme Networks, Inc.)
• Inventors: Fee, Brendan, Kane, Laura, Cullerot, David L., Dobbins, Kurt, Ruffen, David J., Oliver, Chris, Andlauer, Philip, Grant, Thomas A., Bahi, David H., Skubisz, Michael, Len, Theodore, Yohe, Kevin
• Granted Patent: US 7,720,076 B2
• Time in Patent Office: Days
• US Class Current: 370/395.530
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• CPC Class Codes: H04L 12/1877 Measures taken prior to transmission
• CPC Class Codes: H04L 12/1886 with traffic restrictions for efficiency improvement, e.g. involving subnets or subdomains
• CPC Class Codes: H04L 12/46 Interconnection of networks
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 12/467 Arrangements for supporting untagged frames, e.g. port-based VLANs
• CPC Class Codes: H04L 2212/00 Encapsulation of packets
• CPC Class Codes: H04L 41/0213 Standardised network management protocols, e.g. simple network management protocol [SNMP]
• CPC Class Codes: H04L 41/40 using virtualisation of network functions or resources, e.g. SDN or NFV entities
• CPC Class Codes: H04L 45/04 Interdomain routing, e.g. hierarchical routing
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04L 45/24 Multipath
• CPC Class Codes: H04L 45/34 Source routing
• CPC Class Codes: H04L 49/201 Multicast operation; Broadcast operation
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches
• CPC Class Codes: H04L 49/354 for supporting virtual local area networks [VLAN]

Abstract

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.

Claims

1-52. -52. (canceled)

53. A method to provide information of a system in a network, the method comprising the steps of:

creating a local data structure in a network device with an attached end system; and

populating said local data structure with alias information about a locally attached end system identifier and a source port identifier of said network device.

54. The method of claim 53, wherein said step of populating said local data structure is performed in at least one of an implicit manner and an explicit manner.

55. The method of claim 53, wherein said end system identifier includes a MAC address of the attached end system.

56. The method of claim 53, wherein said data structure can further hold additional information identifying at least one of an owner switch, an alias type, a VLAN policy, and a VLAN ID.

57. A method to provide a virtual data structure of a system in a network, the method comprising the steps of:

creating a data structure in a network device with an attached end system;

populating said data structure with alias information and an attached end system identifier; and

reading data from two or more data structures in a network.

58. The method of claim 57, wherein the said virtual data structure is used to establish an association of a MAC address to alias information for a system in the network.

59. The method of claim 57 wherein said virtual data structure is used to establish an association of a MAC address to an IP address for a system in the network.

60. The method of claim 57 further comprising the step of, locating a device in the network.

61. The method of claim 60, wherein the step of locating includes a step of constructing a query for said virtual data structure to retrieve information to locate the device.

62. The method of claim 60, wherein a location of the device comprises an identifier of a network device having said device locally attached.

63. The method of claim 60, wherein a location of the device comprises a network device and a port identifier of the network device having said device locally attached.

64. A method to reduce at least one of broadcast traffic and unknown traffic flooding in a network using information held by a virtual data structure, the method comprising the steps of:

receiving at least one of a broadcast frame and an unknown destination frame; and

reading information from the virtual data structure to establish a MAC address destination of at least one of said broadcast frame and said unknown destination frame.

65. The method of claim 64 further comprising the step of, forwarding at least one of said broadcast frame and said unknown destination frame to said MAC address destination.

66. The method of claim 64 further comprising the step of, sending information from the virtual data structure to a selected network device to support said selected network device'"'"'s direct communication with said MAC address destination.

67. A network device comprising,

a port to receive network traffic;

and

a data processing mechanism configured to create a local data structure that includes at least alias information about a locally attached end system identifier and a source port identifier of said network device.