Invalidity dossier
US 7224668
Control plane security and traffic flow management
Current assignee: Cisco Systems Inc
Added 9/23/2026, 8:05:01 PM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview: US 7,224,668 B1 — "Control Plane Security and Traffic Flow Management"
Bibliographic data (as supplied): US Patent 7,224,668 B1; application US10/307,154; filed 2002-11-27; granted/published 2007-05-29; priority date 2002-11-27. Inventors: Adrian C. Smethurst, Michael F. Keohane, R. Wayne Ogozaly. Original assignee: Cisco Technology, Inc.; current assignee listed as [Cisco Systems Inc.](/litigations/by-plaintiff/Cisco%20Systems%20Inc.) Status listed as expired – lifetime (adjusted expiration 2025-08-23). Classifications include H04L63/1458 (denial of service) and H04L45/60 (router architectures).
Purpose: The patent addresses denial-of-service attacks on internetworking devices such as routers, switches, and firewalls. According to the text, routers separate control plane functions (routing tables, QoS policies, protocols such as BGP and SNMP) from data plane functions (accepting and forwarding transit packets), and control plane processes are attractive attack targets because failure causes widespread disruption. The stated goal is "improved immunity to denial of service attacks, and in general, to provide improved Quality of Service (QoS) for network infrastructure equipment."
Plain-language scope: Existing approaches described in the excerpt—access lists on input interfaces, hardware rate limits (e.g., for SYN, RPF failures, ICMP unreachables), and class/policy maps per interface—are characterized as difficult to deploy across many ports and costly to transit traffic performance. The invention instead treats a collection of control plane processes as a single entity: a uniquely addressable device port (a "control plane port"). Packets destined for control plane processes are directed through that port, so a set of port services unique to the control plane can be applied in aggregate. Packets can be identified as control-plane-destined by implicit packet information (e.g., recognizing a control plane process address), routing/switching decisions, or configuration information. Administrators may define classes of packets (e.g., Telnet SYN) and attach policies such as rate limiting.
Not established by this excerpt: The full claim language, dependent claims, and complete specification text are not included; the omitted portions may qualify or limit the described scope. The excerpt alone does not establish claim scope, validity, enforceability, or the legal effect of the listed status.
Generated 10/1/2026, 9:41:36 PM
Cases on file (0)
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Litigation summary
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Proceedings on file (0)
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No PTAB proceedings on file. This patent has not been challenged via IPR, PGR, or CBM. The absence is itself a signal — well-asserted patents eventually attract IPRs. The LLM analysis below may surface filings the ODP feed hasn’t indexed yet.
PTAB challenges
AIA trial proceedings at the USPTO Patent Trial and Appeal Board — IPR, PGR, and CBM. Petitioners, judge panels, claim-level invalidation outcomes from Final Written Decisions, and Federal Circuit appeals. The single most important defensive datapoint after litigation history.
Assignment history
Inventors, original assignee, and the chain of ownership recorded with the USPTO — including the correspondent attorney who recorded each assignment, since shell-LLC chains often share one repeat-player attorney even when the entity names look unrelated. Surfaces NPE / patent-troll patterns: shell-entity transfers, known asserters in the chain, repeat correspondent fingerprints, pre-litigation assignments, and bankruptcy fire-sales.
Prior art
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Obviousness
Combinations of prior art that suggest the claimed invention would have been obvious under 35 U.S.C. § 103.
Extensions
Patent term adjustments, term extensions, continuations, divisionals, family members, and expiration dates.
Derivative works
Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.