James N Guichard

US Patent:

7408941, Aug 5, 2008

Filed:

Jun 14, 2005

Appl. No.:

11/152523

Inventors:

Luca Martini - Denver CO, US
Keyur Patel - San Jose CA, US
Thomas D. Nadeau - Hampton NH, US
James N. Guichard - Groton MA, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04L 12/28
H04L 12/66
G06F 15/16
G06F 15/173

US Classification:

37039553, 370401, 370469, 709224, 709227, 709238, 709249

Abstract:

A method and computer system for auto-routing of multi-hop pseudowires is presented. A first Provider Edge (PE) device receives an advertisement from a layer 2 (L2) capable network device, the advertisement including routing state for reaching the L2 device. A first Border Gateway Protocol (BGP) table is populated with the routing state for the L2 capable network device which is reachable by way of an address family reserved for L2 end point reachability information. The first PE device advertises the first BGP table information within a first Service Provider (SP) network such that a multi-hop Pseudowire is capable of being established which includes the L2 capable device.

US Patent:

7433320, Oct 7, 2008

Filed:

Feb 1, 2005

Appl. No.:

11/048077

Inventors:

Stefano Previdi - Rome, IT
James N. Guichard - Groton MA, US
Jean-Philippe Vasseur - Dunstable MA, US
David D. Ward - Somerset WI, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04L 12/28
H04L 12/46

US Classification:

370248, 370252, 370254, 370351, 370389

Abstract:

Customer edge (CE) to CE device verification checks initiate routes from available CEs as a set of path verification messages, destined for remote CE routes serving a remote VPN. An extended community attribute, included among the attributes of the path verification message, stores the identity of the originating CE router. The path verification message propagates across the network, and transports the identity of the originating CE router because the originator identity is not overwritten by successive routing. Upon receipt by the remote CE, the originator is determinable from the extended community attribute. A further reachability field is also included in the extended community attribute and indicates whether per CE or per prefix is appropriate for the particular route in question. In this manner, CE-CE connectivity checks identify CEs which are reachable from other CEs. Accordingly, such a mechanism allows for route reachability aggregation on a per-CE or per-prefix reachability basis.

US Patent:

7471636, Dec 30, 2008

Filed:

Feb 23, 2005

Appl. No.:

11/063803

Inventors:

Jean-Philippe Vasseur - Dunstable MA, US
Stefano Previdi - Rome, IT
James N. Guichard - Groton MA, US
David D. Ward - Somerset WI, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04L 12/26

US Classification:

370242, 370252

Abstract:

A data communication device (e. g. , a router) originates a network configuration message in response to a network topology change or so as to refresh a configuration message. The data communication device encodes a timestamp in the network configuration message. The timestamp indicates a time of originating the network configuration message. Further, the data communication device transmits the network configuration message over the network to other network devices that, in turn, initiate further broadcast of at least a portion of contents of the network configuration message. Based on the timestamp of the network configuration message, the data communication devices receiving the network configuration message identify transmission time value indicating how long the network configuration message takes to be conveyed over the network to the other network devices. The data communication devices utilize the transmission time value as a timeout period for determining whether a data communication device failure occurs.

US Patent:

7483387, Jan 27, 2009

Filed:

May 23, 2005

Appl. No.:

11/135600

Inventors:

James Guichard - Groton MA, US
Daniel C. Tappan - Boxborough MA, US
Jean-Philippe Vasseur - Dunstable MA, US
Simon Spraggs - Hayling Island Hants, GB

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04L 12/26
H04L 12/28
H04L 12/56

US Classification:

370252, 370254, 370255, 370389, 370392, 370401

Abstract:

A system and method are provided for separately distributing edge-device labels and routing information across routing areas of a computer network. Because the edge-device labels are distributed separately from network routing information, the process of distributing the edge-device labels does not preclude conventional edge-device address summarizations. Illustratively, a novel “label mapping” LSA is employed for distributing the edge-device labels across routing areas. The label-mapping LSA may be embodied as an area-scope OSPF opaque LSA (type 10) or an IS-IS LSP containing TLVs of area scope. Advantageously, the present invention is generally applicable whenever label values are allocated to edge devices in a multi-area computer network and data is “tunneled” through the network from one edge device to another.

US Patent:

7505402, Mar 17, 2009

Filed:

Jun 23, 2005

Appl. No.:

11/159719

Inventors:

Clarence A. M. Filsfils - Brussels, BE
James N. Guichard - Groton MA, US
Robert Raszuk - Komorow, PL
Jean-Philippe Vasseur - Dunstable, FR
Kris Michielsen - Keerbergen, BE
Peter De Vriendt - Denderleeuw, BE

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

G06F 11/00
G01R 31/08
H04L 12/56

US Classification:

370217, 370221, 370397

Abstract:

A method, apparatus and computer program product for providing convergence for a dual-homed site in a network is presented. An occurrence of a failure between a first Provider Edge (PE) device and a first Customer Edge (CE) device in communication with a dual-homed site is detected. A determination is made whether an alternate route exists for the dual-homed site in a routing table associated with the first PE device. When an alternate route exists then a routing entry associated with the first CE device in a routing table of said first PE device is kept from being deleted for a predetermined amount of time, the routing table is modified to reference the alternate route, the routing entry is rewritten to perform a POP and lookup in a VRF table of the first PE device, and the routing entry is deleted after the predetermined amount of time has elapsed.

US Patent:

7509491, Mar 24, 2009

Filed:

Jun 14, 2004

Appl. No.:

10/867266

Inventors:

W. Scott Wainner - Potomac Falls VA, US
James N. Guichard - Groton MA, US
Brian E. Weis - San Jose CA, US
David A. McGrew - Poolesville MD, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04L 9/00

US Classification:

713163, 726 15

Abstract:

Conventional mechanisms exist for denoting such a communications group (group) and for establishing point-to-point, or unicast, secure connections between members of the communications group. In a particular arrangement, group members employ a group key operable for multicast security for unicast communication, thus avoiding establishing additional unicast keys for each communication between group members. Since the recipient of such a unicast message may not know the source, however, the use of the group key assures the recipient that the sender is a member of the same group. Accordingly, a system which enumerates a set of subranges (subnets) included in a particular group, such as a VPN, and establishing a group key corresponding to the group applies the group key to communications from the group members in the subnet. The group key is associated with the group ID by enumerating the address prefixes corresponding to each of the subnets in the group, and examining outgoing transmissions for destination addresses matching one of the address prefixes corresponding to the group.

US Patent:

7516224, Apr 7, 2009

Filed:

Oct 21, 2004

Appl. No.:

10/970014

Inventors:

James N. Guichard - New Boston NH, US
Mohammed Sayeed - Shrewsbury MA, US
Bertrand Duvivier - Wepion, BE
Daniel Tappan - Boxborough MA, US
W. Scott Wainner - Potomac Falls VA, US
Christopher Metz - Danville CA, US
W. Mark Townsley - Paris, FR
Wojciech Dec - Amsterdam, NL

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

G06F 15/16

US Classification:

709227, 709230, 370401, 370466

Abstract:

A method, apparatus and computer program product for routing data within a packet-switched network using a PW wherein the PW is terminated directly on the layer-3 routing device such that certain services and applications can be utilized is presented. The method, apparatus and computer program product receives an encapsulated layer-2 Protocol Data Unit (PDU) from a pseudowire emulating a service. The encapsulation is removed from the encapsulated layer-2 PDU and a layer-2 circuit associated with the pseudowire is terminated. The circuit is treated as an interface and the PDU is forwarded based on upper layer protocol information within the PDU.

US Patent:

7583593, Sep 1, 2009

Filed:

Dec 1, 2004

Appl. No.:

11/001149

Inventors:

James N. Guichard - Groton MA, US
Jean-Philippe Vasseur - Dunstable MA, US
Thomas D. Nadeau - Hampton NH, US
Clarence A. M. Filsfils - Brussels, BE
David D. Ward - Somerset WI, US
Stefano Previdi - Rome, IT

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

G01R 31/08
H04L 12/26

US Classification:

370225, 370242

Abstract:

A path verification protocol (PVP) which enumerates a series of messages sent to a set of nodes, or routers, along a suspected path identifies forwarding plane problems for effecting changes at the control plane level. The messages include a command requesting interrogation of a further remote node for obtaining information about the path between the node receiving the PVP message and the further remote node. The node receiving the PVP message replies with a command response indicative of the outcome of attempts to reach the further remote node. The series of messages collectively covers a set of important routing points along a path from the originator to the recipient. The aggregate command responses to the series of PVP messages is analyzed to identify not only whether the entire path is operational, but also the location and nature of the problem.