Invalidity dossier
US 6981158
Method and apparatus for tracing packets
Current assignee: Stragent LLC
Added 9/21/2026, 10:20:24 AM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US6981158B1
Title: Method and apparatus for tracing packets
Patent number / authority: US6981158B1 (US)
Application number: US09/881,074
Priority date: 2000-06-19
Filing date: 2001-06-14
Publication date: 2005-12-27
Inventors: Luis Sanchez, William Timothy Strayer, Craig Partridge
Original assignee: BBNT Solutions LLC (listed current assignee: Stragent LLC)
Classification: H04L63/1408 (detecting/protecting against malicious traffic by monitoring network traffic); H04L63/1416 (event/attack signature detection); H04L2463/146 (tracing the source of attacks)
Purpose
The patent relates generally to network security and "more specifically to using low overhead methods for identifying the intrusion location of a packet in a network." The problem addressed is that any router, switch, or computer on the Internet may be a potential entry point for an attack, and malicious packets (including single-packet attacks) are hard to detect and trace. The excerpt explains that source IP addresses are easily forged and untrustworthy, and that most prior-art techniques try to stop malicious packets at the destination rather than locate their origin — referred to as the entry point, ingress point, or intrusion location.
Plain-language scope
Per the excerpt, the invention concerns tracing a packet back to where it entered a network, so that further attacks may be prevented and the actual source identified. The excerpt describes networks of autonomous systems (AS), border routers (e.g., R1 for PAS1, firewall Ft for PAS2, connected by link L1), hosts H1–H5, routing tables, and prior-art devices used to thwart malicious packets. It notes that attacks may be launched via compromised computers or devices, and that tracing under prior art occurs only after the attacking packet has traversed the network.
Not established by the excerpt
The supplied text does not include the full claims, the detailed description, or the abstract, so the precise claimed apparatus and method steps are not established. It does not establish prosecution history, actual ownership status, validity, or the content of any prior art. Litigation and ownership transfers were not researched per instruction.
Source: https://patents.google.com/patent/[US6981158](/patent/US6981158)/en
Generated 10/1/2026, 10:01:46 PM
Cases on file (0)
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Litigation summary
Past and pending lawsuits — plaintiffs, defendants, jurisdictions, outcomes, and notable rulings.
Proceedings on file (0)
All PTAB activity →AIA trial proceedings (IPR / PGR / CBM) filed at the USPTO Patent Trial and Appeal Board against this patent. Sourced from the USPTO Open Data Portal and refreshed every six hours; each proceeding number deep-links to the PTAB E2E docket.
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
Earlier patents, publications, and products that may anticipate or render the claims unpatentable.
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.