Michael E Yip

US Patent:

6618388, Sep 9, 2003

Filed:

Jan 5, 2001

Appl. No.:

09/755736

Inventors:

Michael Yip - Sunnyvale CA
Steve Haddock - Los Gatos CA

Assignee:

Extreme Networks - Santa Clara CA

International Classification:

H04L 1256

US Classification:

370401, 370474

Abstract:

A method and system is provided in which MAN traffic is segregated at a customer and a provider domain level. A switch at the edge of the MAN encapsulates a data packet in a new header, which is used to specify the customer domain tags. The data packet is encapsulated further in another new header, which is used to specify new VMAN tags. The nested encapsulation is repeated as necessary until the data packet is forwarded to a remote switch at the edge of the MAN in accordance with the VMAN configuration or the source and destination address in the original data packet. The remote switch strips the VMAN tags from the data packet, and forwards the stripped data packet to the receiving customer domain as specified in the customer domain tag.

US Patent:

6766482, Jul 20, 2004

Filed:

Oct 31, 2001

Appl. No.:

09/999796

Inventors:

Michael Yip - Sunnyvale CA
Sunil P. Shah - San Jose CA
Michelle M. Ragonese - Burlingame CA

Assignee:

Extreme Networks - Santa Clara CA

International Classification:

G01R 3128

US Classification:

714717, 370216, 370222

Abstract:

A method and apparatus is provided for automatic protection switching in a ring network by creating a protection domain having a control vlan and protected data vlans and designating a master node and transit nodes connected by a primary port and a secondary port. The master node blocks the secondary port for data vlan traffic until it detects a fault either by notice from a transit node or by polling. When a fault is detected, the master node unblocks the secondary port for data vlan traffic. When the fault is restored, the transit node temporarily blocks the restored port to data vlan traffic thereby preventing a loop. Each time the secondary port is blocked and unblocked, the forwarding databases on all the nodes are flushed.

US Patent:

6912592, Jun 28, 2005

Filed:

Jan 5, 2001

Appl. No.:

09/755498

Inventors:

Michael Yip - Sunnyvale CA, US

Assignee:

Extreme Networks, Inc. - Santa Clara CA

International Classification:

G06F015/16

US Classification:

709249, 709218, 709220, 709225, 709230, 370 94, 370 85, 370359, 370392, 370401

Abstract:

A method and system is provided in which data packets from multiple customer VLANs are forwarded over a MAN using VLAN aggregation. A layer-2 switch located at the edge of the MAN connects the customer VLANs to the MAN. The edge switch aggregates multiple customer VLANs (the “sub-VLANs”) into one provider VLAN (the “super-VLAN”). When a packet is forwarded from the sub-VLAN to the super-VLAN and vice versa, the edge switch uses modified bridge forwarding rules to exchange the customer-configured VLAN-IDs with the provider-configured VLAN-IDs before transporting the packet over the MAN. The edge switch further uses modified bridge media access control (MAC) address learning rules to isolate one customer's traffic from another's (i. e. isolate one sub-VLAN's traffic from another sub-VLAN's traffic).

US Patent:

6914905, Jul 5, 2005

Filed:

Jun 16, 2000

Appl. No.:

09/595608

Inventors:

Michael Yip - Sunnyvale CA, US
Shehzad T. Merchant - Mountain View CA, US
Kenneth T. Yin - Rumson NJ, US

Assignee:

Extreme Networks, Inc. - Santa Clara CA

International Classification:

H04L012/56

US Classification:

37039553

Abstract:

A method and system for an aggregated virtual local area network (VLAN) architecture in which several VLANs in a network share the same default router address and subnet mask, but remain isolated from one another's network traffic. Instead of the traditional method of assigning one subnet to a VLAN, each VLAN is assigned only a portion of a subnet's IP address space, and is further grouped into a super-VLAN uniquely associated with that subnet. Intra-VLAN traffic is forwarded only to host IP addresses assigned to that same VLAN according to a VLAN identifier carried in the data packet. Inter-VLAN traffic is processed by a virtual router interface which routes the data packet by applying the routing configuration for the subnet uniquely associated with the super-VLAN, according to a super-VLAN identifier carried in the data packet. The routing configuration used by the virtual router interface includes routing protocols, static routes, redundant router protocols and access-lists. Since each VLAN shares the same virtual router interlace, the traditional address overhead of a subnet is minimized, requiring only one default router and subnet mask, as well as only one pair of subnet broadcast addresses for all hosts on the subnet and the subnet itself.

US Patent:

6954436, Oct 11, 2005

Filed:

Feb 28, 2001

Appl. No.:

09/797475

Inventors:

Michael Yip - Sunnyvale CA, US
Apoorva Bhatt - Belmont CA, US

Assignee:

Extreme Networks, Inc. - Santa Clara CA

International Classification:

H04L012/28

US Classification:

370254, 370217, 370252, 370352, 714 4, 709208, 709220, 709221, 709238

Abstract:

A method for electing a master router in a virtual router network by obtaining a tracking parameter for each of the routers participating in a virtual router network. A priority value is assigned to each of the plurality of routers based on the tracking parameter and reported to each router at periodic intervals. The router with the highest priority value is elected, or re-elected, as the new master. The tracking parameters include a ping tracking parameter obtained by pinging the active routes listed in the routing table for each of the of routers participating in the virtual router network, an environmental tracking parameter obtained by inspecting the operating characteristics outside of the control of the router, including operating temperature and power supply status, and a diagnostic tracking parameter obtained by inspecting the diagnostic data representing operating characteristics within the control of the router, including an operability status of the router's circuitry and channels and a status of the packet-level connectivity to the physical layer backplane network.

US Patent:

6980550, Dec 27, 2005

Filed:

Jan 16, 2001

Appl. No.:

09/761281

Inventors:

Michael Yip - Sunnyvale CA, US
Desikan Saravanan - Santa Clara CA, US
Arthur Lin - Sunnyvale CA, US
Edward Joel Rovner - Chapel Hill NC, US
Tash Hepting - San Jose CA, US
Paul Anderson - San Jose CA, US
Brian Bailey - Monte Sereno CA, US

Assignee:

Extreme Networks, Inc - Santa Clara CA

International Classification:

H04L012/28
H04L012/56

US Classification:

370392, 37039532, 370401

Abstract:

A method for forwarding data packets to one of a plurality of servers comprising receiving a data packet from a source, at a data packet forwarding device having a plurality of ports, performing a hashing function using a unique component of the data packet as a seed value for the hash, generating a hash value using the hashing function, looking up a table for an address of one of the plurality of servers using the hashed value as an index to the table, and forwarding the data packet to a server corresponding to the address.

US Patent:

6992978, Jan 31, 2006

Filed:

Jun 2, 1999

Appl. No.:

09/324454

Inventors:

Pierre A. Humblet - Cambridge MA, US
Bruce D. Miller - North Reading MA, US
Raj Shanmugaraj - Groton MA, US
Steven Sherry - Needham MA, US
Peter B. Beaulieu - Plaistow NH, US
Michael W. Fortuna - Fremont NH, US
Michael C. Yip - Wellesley MA, US
William Abraham - Windham NH, US

Assignee:

Alcatel Communications, Inc. - Plano TX

International Classification:

H04J 11/06
H04J 3/14

US Classification:

370228, 370227

Abstract:

A system and method for fast and reliable failure notification and accelerated switchover for path protection in a communications network having several overlapping areas of nodes interconnected by communications links is described. Upon a failure event involving one of the communications links, a failure message is broadcast identifying the failed link, the broadcast being confined within the areas which include the failed link. A reliable transmission protocol is provided wherein at one or more of the nodes, a LAPD protocol unnumbered information frame containing the failure message is sent to connected nodes. The failure message is resent in another unnumbered information frame after a time interval unless an unnumbered acknowledgment frame containing or referencing the failure message is received from the connected node. A method of path protection includes establishing plural working paths through the nodes. For each working path, an associated protection path is precalculated.

US Patent:

7003705, Feb 21, 2006

Filed:

Jun 17, 2004

Appl. No.:

10/871297

Inventors:

Michael Yip - Sunnyvale CA, US
Sunil P. Shah - San Jose CA, US
Michelle M. Ragonese - Burlingame CA, US

Assignee:

Extreme Networks, Inc. - Santa Clara CA

International Classification:

G01R 31/28

US Classification:

714717, 370216, 370222

Abstract:

A method and apparatus is provided for automatic protection switching in a ring network by creating a protection domain having a control vlan and protected data vlans and designating a master node and transit nodes connected by a primary port and a secondary port. The master node blocks the secondary port for data vlan traffic until it detects a fault either by notice from a transit node or by polling. When a fault is detected, the master node unblocks the secondary port for data vlan traffic. When the fault is restored, the transit node temporarily blocks the restored port to data vlan traffic thereby preventing a loop. Each time the secondary port is blocked and unblocked, the forwarding databases on all the nodes are flushed.