Invalidity dossier
US 5956721
Method and computer program product for classifying network communication packets processed in a network stack
Current assignee: Microsoft Technology Licensing LLC
Added 9/21/2026, 9:31:38 AM
Active provider: DeepSeek · deepseek-flash
Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
US 5,956,721 — Overview
Title: Method and computer program product for classifying network communication packets processed in a network stack
Patent number: US 5,956,721 A
Application number: US 08/933,868
Inventors: John R. Douceur, Yoram Bernet, Ofer Bar
Original assignee: [Microsoft Corp.](/litigations/by-plaintiff/Microsoft%20Corp.) (later listed as Microsoft Technology Licensing, LLC)
Priority/filing date: 1997-09-19
Publication (grant) date: 1999-09-21
Legal status (as listed): Expired – Lifetime; anticipated expiration 2017-09-19
Purpose and plain-language scope. The supplied text frames the invention around classifying network communication packets as they are processed in a network stack. Per the classification headings and prior-art keywords, the approach centers on a classification of packets using a pattern or reference pattern compared against a database, with applications including scheduling or organising servicing of application requests while taking quality-of-service (QoS) or priority requirements into account. Stated benefits in the text include enhanced development, reduced maintenance, and increased performance. Classification areas include layered protocol stacks, parsing or analysis of headers, data-link-layer protocols, and network security protocols. The whole disclosure is presented as a method plus a corresponding computer program product; no claim language is included in the excerpt, so the precise claim scope cannot be stated from this text.
Source: https://patents.google.com/patent/US5956721/en
What the excerpt does not establish. This excerpt does not include the claims, abstract, or description body, so it does not establish the specific steps, elements, or limitations actually claimed, nor any measured results. It does not establish the identity or contents of any prior-art reference or how the invention distinguishes over it. It does not establish inventorship validity, ownership history beyond the recorded assignments shown, enforceability, or whether the "Expired" status is legally conclusive (the source itself notes status listings are assumptions, not legal conclusions). Related family members (EP 1 032 894 B1, EP 1 843 546 B1, JP 3461802 B2, CA 2304145 C, WO 1999/015993 A1, US 6,185,568 B1) appear in the source but are outside this overview's permitted scope.
Generated 10/1/2026, 10:02:15 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)
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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
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.