Patents by Inventor Soei-Shin Hang
Soei-Shin Hang has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8531991Abstract: A solution is provided wherein the interfaces between multiple chassis (e.g., edge switches) in a network of layer 2 devices and a spanning tree device are treated as a single emulated switch. This emulated switch effectively enables two different views to the two different sides. Thus, frames from the network of layer 2 switches destined to any port of the emulated switch may take any of the links (through any of the physical switches), thereby enabling effective load-balancing for frames traveling from the layer 2 network side into the spanning tree device. Meanwhile the spanning tree device does not recognize an illegal loop in its connection to two different edge switches as it views the two links as a single logical EtherChannel.Type: GrantFiled: October 16, 2006Date of Patent: September 10, 2013Assignee: Cisco Technology, Inc.Inventors: Sanjay Sane, Lawrence Kreeger, Thomas Edsall, Elango Ganesan, Soei-Shin Hang, Ramana Mellacheruvu
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Patent number: 7821379Abstract: A network node determines the suitability of coupled devices for being remotely line powered before actually powering them. The node scan its ports to determine which ports are coupled to devices. The node then interrogates the coupled devices. A unique discovery tone or bit pattern is generated and sent to devices coupled to ports. The node then monitors the port for a return signal. If there is a return signal, it is compared to the transmitted discovery signal. The signal will be identical after allowing for line losses if the coupled device is suitable for remote line powering. If the comparison yields a match, the network node supplies remote line power to the device.Type: GrantFiled: May 30, 2007Date of Patent: October 26, 2010Assignee: Cisco Technology, Inc.Inventors: Luca Cafiero, Maurilio De Nicolo, Thomas Edsall, Karl Nakamura, Soei-Shin Hang
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Publication number: 20080089247Abstract: A solution is provided wherein the interfaces between multiple chassis (e.g., edge switches) in a network of layer 2 devices and a spanning tree device are treated as a single emulated switch. This emulated switch effectively enables two different views to the two different sides. Thus, frames from the network of layer 2 switches destined to any port of the emulated switch may take any of the links (through any of the physical switches), thereby enabling effective load-balancing for frames traveling from the layer 2 network side into the spanning tree device. Meanwhile the spanning tree device does not recognize an illegal loop in its connection to two different edge switches as it views the two links as a single logical EtherChannel.Type: ApplicationFiled: October 16, 2006Publication date: April 17, 2008Applicant: Cisco Technology, Inc., A California CorporationInventors: Sanjay Sane, Lawrence Kreeger, Thomas Edsall, Elango Ganesan, Soei-Shin Hang, Ramana Mellacheruvu
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Publication number: 20070222562Abstract: A network node determines the suitability of coupled devices for being remotely line powered before actually powering them. The node scan its ports to determine which ports are coupled to devices. The node then interrogates the coupled devices. A unique discovery tone or bit pattern is generated and sent to devices coupled to ports. The node then monitors the port for a return signal. If there is a return signal, it is compared to the transmitted discovery signal. The signal will be identical after allowing for line losses if the coupled device is suitable for remote line powering. If the comparison yields a match, the network node supplies remote line power to the device.Type: ApplicationFiled: May 30, 2007Publication date: September 27, 2007Applicant: CISCO TECHNOLOGY, INC.Inventors: Luca Cafiero, Maurilio De Nicolo, Thomas Edsall, Karl Nakamura, Soei-Shin Hang
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Patent number: 7256684Abstract: A network node determines the suitability of coupled devices for being remotely line powered before actually powering them. The node scan its ports to determine which ports are coupled to devices. The node then interrogates the coupled devices. A unique discovery tone or bit pattern is generated and sent to devices coupled to ports. The node then monitors the port for a return signal. If there is a return signal, it is compared to the transmitted discovery signal. The signal will be identical after allowing for line losses if the coupled device is suitable for remote line powering. If the comparison yields a match, the network node supplies remote line power to the device.Type: GrantFiled: April 29, 2004Date of Patent: August 14, 2007Assignee: Cisco Technology, Inc.Inventors: Luca Cafiero, Maurilio De Nicolo, Thomas Edsall, Karl Nakamura, Soei-Shin Hang
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Patent number: 6831898Abstract: The invention replicates a packet requiring high availability and transmits it from two or more ports of a switch, for example a wiring closet Layer 2 switch. The parent packet carries a unique sequence number. The copies of the packet each carry the parent packet's unique sequence number. Each copy of the packet then travels on separate pathways through routers (Layer 3 network devices). The pathways are maintained separate by assigning high costs in a LSP routing sense to links connecting the two paths, and by assigning low costs to links along the desired paths. The two identical packets converge on the destination station. The destination station accepts the first packet with a particular sequence number, and discards any later packets with the same sequence number. In the event that a link in one path has a catastrophic failure, then the packet travelling along the other path reaches the destination station and service remains operative without interruption.Type: GrantFiled: August 16, 2000Date of Patent: December 14, 2004Assignee: Cisco Systems, Inc.Inventors: Thomas J. Edsall, Silvano Gai, Soei-Shin Hang
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Patent number: 6762675Abstract: A network node determines the suitability of coupled devices for being remotely line powered before actually powering them. The node scan its ports to determine which ports are coupled to devices. The node then interrogates the coupled devices. A unique discovery tone or bit pattern is generated and sent to devices coupled to ports. The node then monitors the port for a return signal. If there is a return signal, it is compared to the transmitted discovery signal. The signal will be identical after allowing for line losses if the coupled device is suitable for remote line powering. If the comparison yields a match, the network node supplies remote line power to the device.Type: GrantFiled: September 27, 1999Date of Patent: July 13, 2004Assignee: Cisco Technology, Inc.Inventors: Luca Cafiero, Maurilio De Nicolo, Thomas Edsall, Karl Nakamura, Soei-Shin Hang
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Patent number: 6457058Abstract: An improved look up mechanism for accessing a RAM to obtain forwarding information for data frames being transported among ports of a high-performance switch is provided. The look up mechanism includes a multi-page look up table and associated hashing technique. A media access control (MAC) address and a virtual local area network (VLAN) identifier are transformed with a hash function to obtain a hash key. The hash key is an address pointing to a particular entry in the look up table. A virtual first page is also derived from the hash key, which selects a particular physical page of the look up table to be initially accessed each time that MAC address/VLAN pair is used. The look up mechanism may also be used to access a short cut table containing Layer 3 short cut information. In either case, ultimately, the likelihood is increased that a match will be found on the first RAM access, thus maintaining high-speed switch performance.Type: GrantFiled: July 12, 2001Date of Patent: September 24, 2002Assignee: Cisco Technology, Inc.Inventors: Daniel Ullum, Thomas J. Edsall, Soei-Shin Hang
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Patent number: 6266705Abstract: An improved look up mechanism for accessing a RAM to obtain forwarding information for data frames being transported among ports of a high-performance switch is provided. The look up mechanism includes a multi-page look up table and associated hashing technique. A media access control (MAC) address and a virtual local area network (VLAN) identifier are transformed with a hash function to obtain a hash key. The hash key is an address pointing to a particular entry in the look up table. A virtual first page is also derived from the hash key, which selects a particular physical page of the look up table to be initially accessed each time that MAC address/VLAN pair is used. The look up mechanism may also be used to access a short cut table containing Layer 3 short cut information. In either case, ultimately, the likelihood is increased that a match will be found on the first RAM access, thus maintaining high-speed switch performance.Type: GrantFiled: September 29, 1998Date of Patent: July 24, 2001Assignee: Cisco Systems, Inc.Inventors: Daniel Ullum, Thomas J. Edsall, Soei-Shin Hang