DISTRIBUTED CONNECTION-ORIENTED SERVICES FOR SWITCHED COMMUNICATION NETWORKS

• US 20100177778A1
• Filed: 03/23/2010
• Published: 07/15/2010
• 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 8,462,794 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 of forwarding data packets in a switched communications network, the network including end systems and a plurality of switches connected by links, the switches having ports connected to end systems and ports connected to other switches, and each end system having a unique physical address, the method comprising:

populating a directory with MAC address information and with alias address information of a plurality of end systems;

receiving, from a source end system of the plurality of end systems, a packet at a port of an ingress switch of the plurality of switches;

subsequent to receiving the packet at the port of the ingress switch, determining, from the packet, an alias address of the source end system;

obtaining, from the directory, a destination MAC address bound to the alias address;

restricting transmission of the packet to a path from the ingress switch to an egress switch to which a destination end system having the destination MAC address is attached, to forward the packet to the destination end system.

54. The method of claim 53, comprising:

restricting transmission of the packet to the path, wherein the egress switch includes a port connected to the destination end system.

55. The method of claim 53, comprising:

populating a local directory with information limited to information of end systems connected to one switch of the plurality of switches, wherein the information includes MAC address information and alias address information of the end systems connected to the one switch.

56. The method of claim 53, wherein populating the directory comprises:

populating a local directory having information of only a plurality of end systems connected to the ingress switch, wherein the information includes MAC address information and alias address information of the plurality of end systems connected to the ingress switch.

57. The method of claim 53, wherein populating the directory comprises:

populating a virtual directory having MAC address information and alias address information of a plurality of end systems connected to the ingress switch and having MAC address information and alias address information of end systems connected to other switches.

58. The method of claim 53, wherein populating the directory comprises:

populating a virtual directory having MAC address information and alias address information of a plurality of end systems connected to the ingress switch and having MAC address information and alias address information of end systems connected to switches of the switched communications network and to at least one other switch external to the switched communications network.

59. The method of claim 58, wherein the at least one other switch external to the switched communications network includes the egress switch.

60. The method of claim 53, comprising:

populating the directory with a VLAN mapping that identifies the virtual LAN to which at least one of the plurality of end systems belong.

61. The method of claim 53, wherein populating the directory comprises:

populating the directory with MAC address information and with alias address information of the plurality of end systems, wherein the alias information is associated with a virtual LAN to which at least one of the plurality of end systems belong.

62. The method of claim 53, wherein the virtual LAN includes the destination end system.

63. The method of claim 53, wherein the plurality of end systems includes the destination end system.

64. The method of claim 53, further consisting of:

restricting transmission of the packet from the ingress switch to the egress switch to forward the packet to the destination end system.

65. The method of claim 54, comprising:

establishing a connection from the ingress switch to the egress switch.

66. The method of claim 65, further consisting of:

establishing the connection from the ingress switch to the egress switch having the port connected to the destination end system having the destination MAC address.

67. A method of forwarding data packets in a switched communications network, the network including end systems and a plurality of switches connected by links, the switches having ports connected to end systems and ports connected to other switches, and each end system having a unique physical address,

the method consisting of:

populating a directory with MAC address information and with alias address information of a plurality of end systems; and

populating the directory with at least one VLAN mapping that identifies a virtual LAN to which at least one of the plurality of end systems belong;

the method further comprising;

receiving, from a source end system of the plurality of end systems, a packet at a port of an ingress switch of the plurality of switches;

subsequent to receiving the packet at the port of the ingress switch, determining, from the packet, an alias address of the source end system;

obtaining, from the directory, a destination MAC address bound to the alias address; and

transmitting the packet from the ingress switch to an egress switch to which a destination end system having the destination MAC address is attached, to forward the packet to the destination end system.

68. The method of claim 67, further comprising:

tagging the packet with a header prior to transmitting the packet from the ingress switch to the egress switch.

69. The method of claim 67, further comprising:

modifying the packet with path information prior to transmitting the packet from the ingress switch to the egress switch.

70. The method of claim 67, further comprising:

restricting transmission of the packet from the ingress switch to the egress switch to forward the packet to the destination end system.

71. The method of claim 67, further consisting of:

transmitting the packet from the ingress switch to the egress switch to forward the packet to the destination end system.

72. An apparatus for forwarding data packets, comprising:

a switched communications network, the network including end systems and switches connected by links, the switches having ports connected to end systems and ports connected to other switches, and each end system having a unique physical address;

a directory populated with MAC address information and with alias address information of a plurality of end systems, wherein the alias information is associated with a virtual LAN to which at least one of the plurality of end systems belong;

a port of an ingress switch of the plurality of switches, the port configured to receive a packet from a source end system of the plurality of end systems;

the ingress switch configured to determine, from the packet, an alias address of the source end system, and the ingress switch further configured to obtain, from the directory, a destination MAC address bound to the alias address;

a switching engine configured to restrict transmission of the packet from the ingress switch to an egress switch to which a destination end system having the destination MAC address is attached, to forward the packet to the destination end system.

73. The apparatus of claim 72, wherein the directory comprises a local directory with information limited to information of end systems connected to one switch of the plurality of switches, wherein the information includes MAC address information and alias address information of the end systems connected to the one switch.

74. The apparatus of claim 72, wherein the directory comprises a local directory having information of only a plurality of end systems connected to the ingress switch, wherein the information includes MAC address information and alias address information of the plurality of end systems connected to the ingress switch.

75. The apparatus of claim 72, wherein the directory comprises a virtual directory having MAC address information and alias address information of a plurality of end systems connected to the ingress switch and having MAC address information and alias address information of end systems connected to other switches.

76. The apparatus of claim 72, wherein the directory comprises a virtual directory having MAC address information and alias address information of a plurality of end systems connected to the ingress switch and having MAC address information and alias address information of end systems connected to switches of the switched communications network and to at least one other switch external to the switched communications network.

77. A method of forwarding data packets in a switched communications network, the network including a plurality of end systems and switches connected by links, the switches having ports connected to end systems and ports connected to other switches, and each end system having a unique physical address, the method comprising:

receiving, from a source end system of the plurality of end systems, a packet at a port of an ingress switch;

tagging the packet with a VLAN identifier that identifies a VLAN of the source end system to which the packet belongs;

matching the packet with a destination end system connected to a port of an egress switch based on the VLAN identifier that identifies the VLAN of the source end system;

removing, at the egress switch, the VLAN identifier from the packet; and

subsequent to removing the VLAN identifier from the packet, transmitting the packet out of the egress switch, wherein the VLAN identifier matches a VLAN identifier of the destination end system.

78. The method of claim 77, comprising:

tagging the packet with the VLAN identifier that identifies the VLAN of the source end system, wherein at least one other end system is connected to the ingress switch, the at least one other end system having a different VLAN identifier that identifies a different VLAN.

79. The method of claim 77, comprising:

transmitting the packet out of the egress switch, wherein at least one other end system is connected to the egress switch, the at least one other end system having a different VLAN identifier that identifies a different VLAN.

80. The method of claim 77, consisting of:

tagging the packet with the VLAN identifier that identifies the VLAN of the source end system, wherein at least one other end system is connected to the ingress switch, the at least one other end system having a different VLAN identifier that identifies a different VLAN.

81. The method of claim 77, consisting of:

transmitting the packet out of the egress switch, wherein at least one other end system is connected to the egress switch, the at least one other end system having a different VLAN identifier that identifies a different VLAN.