Xiaohong G Pan

US Patent:

7936666, May 3, 2011

Filed:

Apr 18, 2008

Appl. No.:

12/106176

Inventors:

David Cheung - Cupertino CA, US
Xiaohong Pan - Fremont CA, US

Assignee:

Foundry Networks, LLC - San Jose CA

International Classification:

G01R 31/08

US Classification:

370219, 370220

Abstract:

A virtual router spans a number of physical routing devices. A set of physical ports on one of the physical routing devices is logically represented as a trunk. A respective port priority value is associated with each of those ports, and a device priority value is associated with the physical routing device. If a port in the trunk is out-of-service, then the device priority value can be adjusted by the port priority value associated with the out-of-service port. A corrective action can be implemented if the device priority value fails to satisfy a condition. For example, the physical routing device may failover to another one of the physical routing devices spanned by the virtual router.

US Patent:

8014409, Sep 6, 2011

Filed:

May 30, 2008

Appl. No.:

12/130721

Inventors:

Xiaohong Pan - Fremont CA, US

Assignee:

Foundry Networks, LLC - San Jose CA

International Classification:

H04L 12/56

US Classification:

370401, 370221, 370228

Abstract:

A virtual router spans a number of physical routing devices. One of the physical routing devices is designated as master, and the other physical routing devices are designated as backups to the master. The virtual router may be situated between a first local area network and a second local area network. A virtual router identifier can be associated with multiple interfaces on each of the physical routing devices.

US Patent:

8199641, Jun 12, 2012

Filed:

Jul 25, 2008

Appl. No.:

12/179703

Inventors:

Rangaswamy Jagannathan - Sunnyvale CA, US
Rosanna Lee - Palo Alto CA, US
Derek Sanders - Saratoga CA, US
Xiaohong Pan - Fremont CA, US
Kishor Kakatkar - Santa Clara CA, US

Assignee:

Xangati, Inc. - Cupertino CA

International Classification:

H04L 12/26
G06F 15/173

US Classification:

370229, 709224

Abstract:

A network monitoring system includes devices receiving network traffic information, and generating at least partial results relating to network symptoms. Those partial results are forwarded to devices processing those partial results and generating information relating to problems in response to those symptoms. Problems are reported to users or sent as notifications. In one embodiment, information relating to network traffic is monitored both by a first set of devices associated with source addresses for that network traffic and a second set of devices associated with destination addresses for that network traffic. Information received by that first set of devices includes information relating to both the source address and destination address of network traffic. That first set of devices processes information relating to the source address of network traffic and forwards information relating to the destination address of network traffic to that second set of devices.

US Patent:

8339943, Dec 25, 2012

Filed:

Mar 30, 2011

Appl. No.:

13/076222

Inventors:

Xiaohong Pan - Fremont CA, US

Assignee:

Foundry Networks LLC - San Jose CA

International Classification:

H04L 12/26

US Classification:

370219, 370220, 370221, 370225, 370357, 709238

Abstract:

A virtual router spans a number of physical routing devices. One of the physical routing devices is designated as master, and the other physical routing devices are designated as backups to the master. A failover protocol that includes both a non-dampened state and a dampened state can be implemented. According to the failover protocol, an attempt to designate one of the backups as master in place of the current master is permitted while the virtual router is in the non-dampened state, while such an attempt is suppressed while the virtual router is in the dampened state.

US Patent:

8451731, May 28, 2013

Filed:

Jul 25, 2008

Appl. No.:

12/180193

Inventors:

Rosanna Lee - Palo Alto CA, US
Hong Zhu - Diamond Bar CA, US
Rangaswamy Jagannathan - Sunnyvale CA, US
Xiaohong Pan - San Ramon CA, US
Derek Sanders - Saratoga CA, US
Kishor Kakatkar - Pune, IN
Jing Liu - Cupertino CA, US

Assignee:

Xangati, Inc. - Cupertino CA

International Classification:

H04J 1/16
H04J 3/14
G06F 15/173

US Classification:

370235, 370253, 709224

Abstract:

A network monitoring device includes a flow processing element, disposed to receive flow information relating to network flows, and to generate a set of virtual packets, each representing a portion of a network flow. The virtual packets are maintained in a time-sequential order, and read by elements of the network monitoring device to generate information relating to network traffic, such as symptoms affecting the communication network, problems affecting the communication network, and otherwise. The network monitoring device randomly samples virtual packets, with at least one of two effects: (1) flow information from traffic reporting devices that are themselves sampling at differing rates can be equalized, with the effect of standardizing information from all of them; (2) the network monitoring device itself can restrict its attention to a fraction of all virtual packets, with the effect of keeping up with a relatively large number of virtual packets.

US Patent:

8619552, Dec 31, 2013

Filed:

Apr 27, 2011

Appl. No.:

13/095695

Inventors:

David Cheung - Cupertino CA, US
Xiaohong Pan - Fremont CA, US

Assignee:

Foundry Networks LLC - San Jose CA

International Classification:

H04J 1/16

US Classification:

370219, 370220, 709224, 709239

Abstract:

A virtual router spans a number of physical routing devices. A set of physical ports on one of the physical routing devices is logically represented as a trunk. A respective port priority value is associated with each of those ports, and a device priority value is associated with the physical routing device. If a port in the trunk is out-of-service, then the device priority value can be adjusted by the port priority value associated with the out-of-service port. A corrective action can be implemented if the device priority value fails to satisfy a condition. For example, the physical routing device may failover to another one of the physical routing devices spanned by the virtual router.

US Patent:

8639797, Jan 28, 2014

Filed:

Jul 25, 2008

Appl. No.:

12/180243

Inventors:

Xiaohong Pan - Fremont CA, US
Kishor Kakatkar - Santa Clara CA, US
Derek Sanders - Saratoga CA, US
Rangaswamy Jagannathan - Sunnyvale CA, US
Jing Liu - Cupertino CA, US
Rosanna Lee - Palo Alto CA, US

Assignee:

Xangati, Inc. - Cupertino CA

International Classification:

G06F 15/173

US Classification:

709224, 709223, 709225, 709226

Abstract:

A network monitoring system maintains both information regarding historical activity of a network, and information regarding emergent activity of the network. Comparison of historical activity of the network with emergent activity of the network allows the system to determine whether network activity is changing over time. The network monitoring system maintains data structures representing a p. d. f. for observable values of network parameters. Recent activity of the network can be compared with both the p. d. f. for historical activity and for emergent activity to aid in determining whether that recent activity is within the realm of normal, and whether network activity is changing over time. The network monitoring system adjusts that information regarding historical activity of a network in response to emergent activity of that network. The network monitoring device determines information regarding time-dependent activity of that network in response to spectral analysis regarding historical activity of that network.

US Patent:

8645527, Feb 4, 2014

Filed:

Jul 25, 2008

Appl. No.:

12/180333

Inventors:

Rosanna Lee - Palo Alto CA, US
Xiaohong Pan - Fremont CA, US
Rangaswamy Jagannathan - Sunnyvale CA, US
Derek Sanders - Saratoga CA, US
Kishor Kakatkar - Kothrud, IN

Assignee:

Xangati, Inc. - Cupertino CA

International Classification:

G06F 15/16
G06F 15/173
G06F 3/00

US Classification:

709224, 709201, 709205, 709245, 709246, 710 29

Abstract:

A network monitoring device includes a data structure for maintaining information about endpoints involved in network flows. Each endpoint, either a source or a destination for a network flow, has information maintained in a modified binary trie, having a branch for each bit of the source or destination address, but with interior nodes having only a single child node elided. A pruning thread is given a limited amount of time for operation, with the effect that the data structure is maintained available for use except for only that limited amount of time. In the event that the pruning thread is unable to prune the entire data structure, it maintains a marker indicating where last it left off, and returns to that location in the data structure at a later pruning operation.