Ram G Krishnan

US Patent:

6961809, Nov 1, 2005

Filed:

Dec 17, 2002

Appl. No.:

10/321871

Inventors:

Ram Krishnan - Santa Clara CA, US
Apurva Mehta - Cupertino CA, US
Michael R. MacFaden - San Jose CA, US

Assignee:

Riverstone Networks, Inc. - Santa Clara CA

International Classification:

G06F012/00

US Classification:

711108

Abstract:

Managing a position-dependent data set that is stored in a content addressable memory (CAM) array involves identifying an instance of a base position-dependent data set that exists in software, identifying an instance of an edited position-dependent data set that exists in software, determining differences between the instance of the base position-dependent data set that exists in software and the instance of the edited position-dependent data set that exists in software, and incorporating the differences between the instance of the base position-dependent data set that exists in software and the instance of the edited position-dependent data set that exists in software into an instance of said base position-dependent data set that exists in a CAM array.

US Patent:

7181567, Feb 20, 2007

Filed:

Jun 4, 2003

Appl. No.:

10/454103

Inventors:

Ram Krishnan - Santa Clara CA, US

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

G06F 12/00

US Classification:

711108, 365 49, 365 50, 711205, 711207

Abstract:

Performing selective update of a content addressable memory (CAM) following restart of an access control module (ACM) at a network node involves maintaining a restart CAM entry database in shared memory. When the ACM restarts, instead of reentering all CAM entries into the CAM or reading the contents of the CAM, the ACM only updates the CAM with the entries that were modified while the ACM was offline, prior to restart.

US Patent:

7325071, Jan 29, 2008

Filed:

Jan 10, 2003

Appl. No.:

10/340113

Inventors:

Ram Krishnan - Santa Clara CA, US

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

G06F 15/173
H04L 12/28
G06F 15/16
H04L 12/56

US Classification:

709238, 709217, 37039531

Abstract:

A method and system for forwarding traffic from a plurality of logical networks using a single forwarding table. Traffic is received in the form of packets with a key and a logical traffic identifier. The routing table is traversed to a forwarding table entry having a longest prefixed search value that matches the key and having a logical network identification array in which the logical traffic identifier may be represented. If the logical traffic identifier is represented in the logical network identification array, then the packet is forwarded in accordance with forwarding information associated with the forwarding table entry.

US Patent:

7327727, Feb 5, 2008

Filed:

May 30, 2003

Appl. No.:

10/449628

Inventors:

Scott Rich - Sunnyvale CA, US
Sandeep Lodha - Sunnyvale CA, US
Ram Krishnan - Santa Clara CA, US
Robert Pfile - Oakland CA, US

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H04L 12/28
H04L 12/56

US Classification:

370389, 370392, 370382, 711108, 711216, 709238, 709204

Abstract:

Performing atomic lookup rule set transitions. A method involves performing lookups using a first set of rules, flagging a subset of the first set of rules as old rules, adding a second set of rules while continuing to perform lookups using the first set of rules, and atomically transitioning to perform lookups using the first set of rules plus the second set of rules minus the old rules. A system implementing the method includes a lookup table and a lookup table management module that is configured to make atomic lookup rule set transitions in the lookup table.

US Patent:

7552275, Jun 23, 2009

Filed:

Apr 3, 2006

Appl. No.:

11/397491

Inventors:

Ram Krishnan - Sunnyvale CA, US

Assignee:

Extreme Networks, Inc. - Santa Clara CA

International Classification:

G06F 12/00
G11C 15/00

US Classification:

711108, 711205, 711206, 365 491

Abstract:

In a packet switching device or system, such as a router, switch, combination router/switch, or component thereof, a method of and system for performing a table lookup operation using a lookup table index that exceeds a CAM key size is provided. Multiple CAM accesses are performed, each using a CAM key derived from a subset of lookup table index, resulting in one or more CAM entries. One or more matching table entries are derived from the one or more CAM entries resulting from the multiple CAM accesses.

US Patent:

7908431, Mar 15, 2011

Filed:

Jun 22, 2009

Appl. No.:

12/489034

Inventors:

Ram Krishnan - Sunnyvale CA, US

Assignee:

Extreme Networks, Inc. - Santa Clara CA

International Classification:

G06F 12/00

US Classification:

711108, 709238

Abstract:

In a packet switching device or system, such as a router, switch, combination router/switch, or component thereof, a method of and system for performing a table lookup operation using a lookup table index that exceeds a CAM key size is provided. Multiple CAM accesses are performed, each using a CAM key derived from a subset of lookup table index, resulting in one or more CAM entries. One or more matching table entries are derived from the one or more CAM entries resulting from the multiple CAM accesses.

US Patent:

7912091, Mar 22, 2011

Filed:

Mar 18, 2009

Appl. No.:

12/406790

Inventors:

Ram Krishnan - Sunnyvale CA, US
Prakash Kashyap - Cupertino CA, US

Assignee:

Extreme Networks, Inc. - Santa Clara CA

International Classification:

H04L 12/56

US Classification:

370490, 709224

Abstract:

A data packet is received at a network switch. The packet has a destination address that is reached via a Link Aggregation group on a virtual local area network (VLAN). A forwarding database lookup is performed to determine a Link Aggregation port reference number for the data packet on the VLAN. A Link Aggregation port table is then searched to determine the primary Link Aggregation port and a backup Link Aggregation port for forwarding the packet. A port array for ports in the Link Aggregation group is searched to determine if the primary Link Aggregation port is valid. If the primary port is valid, then the packet is forwarded on the primary Link Aggregation port. If the primary port is not valid, then the packet is forwarded on the backup Link Aggregation port.

US Patent:

7936764, May 3, 2011

Filed:

Apr 9, 2008

Appl. No.:

12/100246

Inventors:

Ram Krishnan - Sunnyvale CA, US

Assignee:

Extreme Networks, Inc. - Santa Clara CA

International Classification:

H04L 12/28

US Classification:

37039531, 370401

Abstract:

A subset of route entries having the same next hop is identified in a route table. The subset of entries falls within a range of prefixes. Gaps in the subset of route entries that prevent the subset from being contiguous are identified. The gaps in the subset are filled with route entries to make the subset contiguous. All of the route entries in the contiguous subset of route entries have the same next hop, thus the contiguous subset can be aggregated into a single route entry in a forwarding table. For each gap-filling entry added to the route table, an additional route entry having forwarding priority over the gap-filling entry is added to the forwarding table.