US 6934279

I'll search for authoritative information on this patent and check for any 2026 CAFC docket activity.

Let me run a few more targeted queries to check for 2026 Federal Circuit activity and confirm the record.

US Patent 6,934,279 B1 — Summary

Note on identifiers: I interpreted "6934279" literally as US 6,934,279. Be aware that the bare string "6934279" also appears in unrelated contexts (e.g., JP Patent No. 6934279 for an imaging optical lens, and a Portuguese publication PT 6934279 A); those are not this patent and are excluded.

Bibliographic data

Related family: PCT/US2001/007686 (WO 2001069899 A2), EP 1266516 B1, AU 2001245590 A1, and continuation application 11/210,084 (US 7,995,589 B2, issued 2011-08-09), which shares the same title and priority date.

Abstract (verbatim)

A method and apparatus of communicating over a data network includes providing a user interface in a control system for call control and to display information relating to a call session. The control system communicates one or more control messages (e.g., Session Initiation Protocol or SIP messages) over the data network to establish a call session with a remote device in response to receipt of a request through the user interface. One or more commands are transmitted to a voice device associated with the control system to establish the call session between the voice device and the remote device over the data network. A Real-Time Protocol (RTP) link may be established between the voice device and the remote device.

Plain-language overview of the independent claims

• Claim 1 (method): A computer ("control system") presents a user interface for making calls. When the user acts through that interface, the computer — not the phone — sends the signaling (control messages) over the data network to set up a call session with a remote device. Separately, the computer sends commands to a "voice device" that is connected to the data network and paired with the computer, so that the actual call session is carried between that voice device and the remote device over the data network. In short: the computer does the signaling; the phone carries the voice.

• Claim 12 (method): The control system itself sends the control messages over the data network to establish a call with a remote device, sends commands to a voice device, the call session is then established between the voice device and the remote device over the data network, and information about the call session is displayed on the control system. This is the same split-control concept, with the added requirement that the computer displays call-session information to the user.

• Claim 25 (system): An apparatus claim covering the computer side. It recites (a) a user interface with call-control selectors, (b) a controller that takes a request from the user interface and generates messages sent over the data network to set up a call session with a remote device, and (c) an interface that sends commands relating to the call session to the voice device so that a link is established between the voice device and the remote device over the data network.

• Claim 32 (article of manufacture): A machine-readable storage medium holding instructions that, when run, make a system: (a) provide a user interface displaying call-session information, (b) exchange control messages over the data network with a remote device to establish the call session between a voice device and the remote device, and (c) control the voice device during the call session. This is the software/media form of the same invention.

• Claim 36 (data signal in a carrier wave): A carrier-wave-embodied data signal containing code segments that cause a system to provide a user interface for establishing a call session, send control messages over the data network to set up the session with a remote device in response to a user request, and transmit commands to a network-connected voice device paired with the control system so the session is established between the voice device and the remote device. This is the signal/transmission form of the claim-1 subject matter.

Dependent claims add, among other things: different message formats for signaling vs. commands (claim 2); a network telephone with a network interface as the voice device (claim 3); RTP session establishment (claim 4); SIP control messages (claims 6, 14, 26, 33); storing the voice device's IP address and port (claims 7–8); receiving an indication from the voice device to start another call (claim 9); GUI display of call information (claims 10, 13, 30–31); termination via either the UI or the voice device (claim 11); user-selectable choice between using the computer's own voice processing components and the network telephone (claims 21–23); and displaying a picture of a callee or call-control icons (claims 34–35).

Litigation / CAFC status — including 2026 check

No 2026 Federal Circuit docket involving this patent surfaced in my searches. I could not find any CAFC 2026 filing, appeal, or oral-argument entry for US 6,934,279 or its continuation US 7,995,589. Two caveats: (1) I do not have direct live query access to PACER/CM-ECF or the Federal Circuit's docket system — the search tool results are what I can verify; and (2) the patent expired on 2020-03-13, making a new infringement appeal filed in 2026 unlikely.

What I did find (documented litigation history):

• Genband US LLC v. Metaswitch Networks Corp., No. 2:14-cv-00033 (E.D. Tex., filed 2014-01-21, closed 2018-04-10). The '279 patent was among the patents-in-suit (along with US 6,772,210; 6,791,971; 6,885,658; 7,047,561; 7,184,427; 7,990,984; and 7,995,589). Claim construction order was issued in 2015.
• Federal Circuit appeal from that case: Genband US LLC v. Metaswitch Networks Corp., 861 F.3d 1378 (Fed. Cir. 2017) — addressing permanent-injunction/causal-nexus and equitable defenses (laches, estoppel, implied license). Google Patents also lists this family's CAFC dockets as 17-1148 and 18-1869 (both 2017–2018, not 2026).
• Sonus Networks, Inc. v. Metaswitch Networks Ltd et al, No. 2:18-cv-00155 (E.D. Tex., filed 2018). Per the Stanford NPE Litigation Database, this is the case in which US 6,934,279 was asserted.
• An earlier Delaware District Court case is also listed for this family: No. 1:07-cv-00507.

Uncertainty notes

• The Google Patents record lists the original assignee as Nortel Networks Ltd while the assignment reel entries show the March 13, 2000 assignment to Nortel Networks Corporation followed by a 2000-08-30 name change to Nortel Networks Limited. I have reported both rather than reconciling them.
• Current ownership chain runs Nortel → Genband US LLC → (Ribbon Communications Operating Company, Inc.), with several security-interest/termination filings in between. The exact present holder depends on how you treat a corporate rename; I flag this as not fully verified.
• I have not independently verified adverse validity rulings or IPR outcomes for this specific patent; none were surfaced in the searches, and the patent's "Expired – Lifetime" status is Google Patents' characterization, not a legal conclusion.

I'll research litigation involving US patent 6934279, starting with the sources you specified.

Let me dig into the specific case numbers referenced in the patent record.

Litigation Involving U.S. Patent No. 6,934,279

Patent identified literally as US 6,934,279 B1 ("Controlling voice communications over a data network"), filed 2000‑03‑13, granted 2005‑08‑23, originally assigned to Nortel Networks Ltd., with current assignee of record Genband US LLC / Ribbon Communications Operating Company, Inc. (successor). In the litigation documents below it is referred to as "the '279 Patent." I have not substituted or corrected any patent or case identifiers.

The patent record itself flags five litigation dockets, and independent litigation databases confirm four distinct proceedings (two district‑court actions, one appeal, plus a related stay‑pending‑appeal). Details below.

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1. Vonage Holdings Corp. v. Nortel Networks Inc. and Nortel Networks Ltd.

• Plaintiff(s): Vonage Holdings Corp. (declaratory‑judgment plaintiff)
• Defendant(s): Nortel Networks Inc. and Nortel Networks Ltd. (Nortel subsequently became counterclaimant/asserting party)
• Jurisdiction/Court: [U.S. District Court for the District of Delaware (Wilmington)](/courts/district-of-delaware-wilmington), Judge Gregory M. Sleet (docketed "‑GMS"; initially referred to Magistrate Judge Leonard P. Stark pending a vacant judgeship)
• Case No.: 1:07‑cv‑00507
• Filing Date: August 17, 2007
• Role of the '279 patent: Vonage's DJ complaint initially targeted three Nortel patents (6,091,808; 6,445,695; 7,050,861). Nortel counterclaimed on December 14, 2007, asserting willful infringement of twelve Nortel patents — including U.S. Patent No. 6,934,279 (asserted as "Claim 8" of Nortel's counter‑counterclaim). Note: the '279 patent is a different patent from the continuation 7,995,589 often asserted alongside it.
• Outcome/Status: Resolved by Stipulation of Dismissal Without Prejudice filed March 12, 2008, "in accordance with a Patent Settlement Agreement," each party to bear its own costs (Doc. 34). Case closed.
• Sources: Google Patents litigation link (Delaware Dist. Court, 1:07‑cv‑00507); https://dockets.justia.com/docket/delaware/dedce/1:2007cv00507/38754 ; counterclaim text (Doc. 28, 12/14/2007) and dismissal (Doc. 34, 03/12/2008).

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2. Genband US LLC v. Metaswitch Networks Corp. et al.

• Plaintiff(s): Genband US LLC (Nortel successor‑in‑interest)
• Defendant(s): Metaswitch Networks Ltd.; Metaswitch Networks Corp.
• Jurisdiction/Court: U.S. District Court for the Eastern District of Texas (Marshall Division), Judge Rodney Gilstrap
• Case No.: 2:14‑cv‑00033 (‑JRG)
• Filing Date: January 21, 2014
• Role of the '279 patent: One of the patents‑in‑suit. The complaint asserted U.S. Patent Nos. 6,772,210; 6,791,971; 6,885,658; 6,934,279 ("the '279 Patent"); 7,047,561; 7,184,427; 7,990,984; and 7,995,589 (the "patents‑in‑suit").
• Outcome/Status: Bench trial held March 29, 2016; the court issued an Order and Opinion with Findings of Fact and Conclusions of Law on September 29, 2016 (Doc. 582), rejecting Metaswitch's equitable defenses (including laches) and denying Genband's request for a permanent injunction. Case closed April 10, 2018. The injunction denial was appealed (see appeal below).
• Sources: Google Patents litigation link (E.D. Tex. 2:14‑cv‑00033); https://cases.justia.com/federal/district-courts/texas/txedce/2:2014cv00033/[149788/310](https://assignmentcenter.uspto.gov/search/patent/reelFrameDetail?reelFrame=149788-0310)/0.pdf ; https://www.docketalarm.com/cases/Texas_Eastern_District_Court/2--14-cv-00033/GENBAND_US_LLC_v._Metaswitch_Networks_Corp._et_al/docs/582.pdf

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3. Appeal — Genband US LLC v. Metaswitch Networks Corp., Fed. Cir. No. 2017‑1148

• Appellant: Genband US LLC
• Appellee: Metaswitch Networks Corp. / Metaswitch Networks Ltd.
• Jurisdiction/Court: U.S. Court of Appeals for the Federal Circuit (Panel: Judges Lourie, Taranto, Chen; opinion authored by Judge Taranto)
• Case No.: 2017‑1148 (appeal from E.D. Tex. 2:14‑cv‑00033)
• Filing Date: 2017 (appeal docketed); decided July 10, 2017
• Outcome/Status: The Federal Circuit vacated the district court's denial of a permanent injunction and remanded for the district court to consider whether there was an independent ground supporting denial of an injunction. Reported as Genband US LLC v. Metaswitch Networks Corp., 861 F.3d 1378 (Fed. Cir. 2017). (Jurisdiction was under 28 U.S.C. § 1292(a), (c)(1).)
• Sources: Google Patents litigation link (Fed. Cir. 17‑1148); https://www.courtlistener.com/opinion/[4407474](/patent/4407474)/genband-us-llc-v-metaswitch-networks-corp/ ; 17‑1148 opinion PDF: https://ipwatchdog.com/wp-content/uploads/2017/07/17-1148.Opinion.7-6-2017.1.pdf

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4. Sonus Networks, Inc. v. Metaswitch Networks Ltd. et al.

• Plaintiff(s): Sonus Networks, Inc. (name later associated with Ribbon Communications in the same docket — a Genband/Sonus successor entity)
• Defendant(s): Metaswitch Networks Ltd.; Metaswitch Networks Corp.
• Jurisdiction/Court: U.S. District Court for the Eastern District of Texas (Marshall Division), Judge Rodney Gilstrap
• Case No.: 2:18‑cv‑00155
• Filing Date: April 18, 2018
• Role of the '279 patent: The Stanford NPE Litigation Database lists this case as involving U.S. Patent 6,934,279 (the '279 patent was among the asserted patents; docket filings also reference '664, '703, '144, '238, '269, '334 and '561 patents in related motion practice).
• Outcome/Status: This action was filed while the related 2:14‑cv‑00033 case was on appeal (Metaswitch filed an "Opposed Motion to Stay Pending Appeal of Related ‑33 Case," Nov. 6, 2018). The parties mediated and reached a post‑mediation settlement (Report of Mediation, April 22, 2019); a Joint Notice of Settlement and Notice of Stay of Federal Circuit Appeal was filed April 25, 2019; and an Agreed Motion to Dismiss with Prejudice was granted by Order on July 1, 2019. Case closed.
• Sources: Google Patents litigation link (E.D. Tex. 2:18‑cv‑00155); Stanford NPE Database, https://npe.law.stanford.edu/patent/6934279 ; https://portal.unifiedpatents.com/litigation/Texas%20Eastern%20District%20Court/case/2%3A18-cv-00155 ; https://dockets.justia.com/docket/texas/txedce/2:2018cv00155/[181821](/patent/181821)

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5. Fed. Cir. No. 2018‑1869 (appeal)

• The patent record lists a second Federal Circuit appeal, No. 2018‑1869 (Google Patents litigation link: Court of Appeals for the Federal Circuit, case 18‑1869). Given the timeline, it appears related to the E.D. Tex. 2:14‑cv‑00033 merits/validity cross‑appeals following the bench trial (the "related ‑33 Case" referenced in the 2:18‑cv‑00155 docket). I could not confirm the precise parties, disposition, or whether it was consolidated with another appeal from the searches run, so I flag this as an unverified entry rather than asserting details.

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Summary Table

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Notes and Caveats

• Foreign/EP family: The '279 patent's family includes EP 1,266,516 B1, WO 01/69899 A2, and AU 2001245590 A1. A European counterpart proceeding would be non‑U.S.; I did not identify any U.S. litigation beyond the entries above.
• Do not confuse with similarly numbered patents: "the '427 patent" appearing in the same cases is U.S. Patent No. 7,184,427, and "the '589 patent" is 7,995,589 (the continuation of the '279 patent). Neither is the '279 patent. Celgene "‑427 patent" results that surfaced in searching are a science‑unrelated red herring.
• Confidence: Cases 1–3 are confirmed by district‑court/CAFC records. Case 4 is confirmed as a case involving the patent by the Stanford NPE Database and the Unified Patents portal, with the dismissal record confirmed via the docket. Case 5 (18‑1869) is documented only as a litigation link on the Google Patents page and is otherwise unverified in the searches I ran.

Primary sources consulted: Google Patents record for US6934279B1 (litigation links), Stanford NPE Litigation Database (patent 6934279), Unified Patents litigation portal (E.D. Tex. 2:14‑cv‑00033, 2:18‑cv‑00155; Fed. Cir. 17‑1148 and 18‑1869), Dockets.Justia.com (D. Del. 1:07‑cv‑00507 and E.D. Tex. 2:18‑cv‑00155), and Federal Circuit opinions via CourtListener/IPWatchdog.

I'll start by verifying the PTAB record for this patent, since the structured block reports no AIA proceedings on file.

The initial searches returned unrelated hits (JP 6934279 is a different, Japanese optical-lens patent). Let me search more precisely.

No PTAB hits yet — only district court litigation. Let me run targeted IPR-specific searches.

Proceedings overview

Total AIA trial proceedings on file for US 6,934,279: 0. The structured "PTAB proceedings on file" block (USPTO Open Data Portal) returns no IPR, PGR, or CBM for this patent, and I found no PTAB proceeding naming US 6,934,279 in web sources; my targeted searches surfaced only district court and Federal Circuit activity. Because the canonical list is empty, there are no per-proceeding entries to report below — the template's per-proceeding sections would be fabrication if filled in, so I have left them out and instead documented the parallel litigation and the resulting defensive posture. The bottom line for a defendant: no claim of this patent has ever been canceled or even tested at the PTAB, and no § 315(e) estoppel exists against anyone. The patent is untested at the Board — but it is also expired (anticipated expiration 2020-03-13, status "Expired - Lifetime"), which materially limits the practical value of an IPR today.

No proceedings — verification trail

• USPTO ODP: no AIA trial proceedings as of the most recent ingest (per the structured block supplied in this prompt).
• Web search: no IPR/PGR/CBM petition naming US 6,934,279 located. Searching PTAB-related terms returns a different, unrelated "279 patent" — a network-resource/optical-transport patent litigated in an IPR involving Kovvali art and a "spatial reuse protocol" (see e.g. the PTAB hearing transcript at https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1555269](/patent/1555269)/download-documents). Do not conflate that proceeding with US 6,934,279. Likewise, the Japanese Patent No. 6934279 (an imaging optical lens, AAAC Optics) is unrelated.
• Caution: I could not confirm or deny the existence of a recently filed, not-yet-indexed petition beyond my search coverage. The ODP default ("no PTAB activity on file") is the reliable statement; a manual PTAB E2E / Patent Center check is the confirming step.

What actually happened to this patent (non-PTAB record, useful to a defendant)

Because the trial record is the only adversarial testing the claims have received, it is the substitute for an FWD:

• Genband US LLC v. Metaswitch Networks Ltd., No. 2:14-cv-00033-JRG (E.D. Tex.). Filed 2014-01-21 (docketed 2014-01-24). Genband asserted eight patents including US 6,934,279 and its continuation US 7,995,589. The claims actually put before the jury included '279 claim 25 and '589 claim 15 (also '971 claims 70/80/92, '658 claims 1/11, '561 claims 6/17/20, etc.). Source: https://cases.justia.com/federal/district-courts/texas/txedce/2:2014cv00033/[149788/582](https://assignmentcenter.uspto.gov/search/patent/reelFrameDetail?reelFrame=149788-0582)/0.pdf
• 2016-01-15 — jury verdict: Metaswitch infringed all asserted claims and the claims were not invalid; damages $8,168,400. The jury rejected Metaswitch's § 102/§ 103 challenges to the '561, '971, '279, and '589 patents (FF19). This is the single most important defensive datum: the obviousness/anticipation case on '279 claim 25 was litigated to a jury and lost.
• 2016-09-29 — post-trial order and JMOL denial: court rejected Metaswitch's equitable defenses (laches, implied waiver, equitable estoppel, implied license) and denied JMOL on infringement and invalidity. https://cases.justia.com/federal/district-courts/texas/txedce/2:2014cv00033/[149788/581](https://assignmentcenter.uspto.gov/search/patent/reelFrameDetail?reelFrame=149788-0581)/0.pdf
• Federal Circuit No. 2017-1148 — 2017-07-10: Genband US LLC v. Metaswitch Networks Corp., 861 F.3d 1378 (Fed. Cir. 2017) (Lourie, Taranto, Chen; Taranto, J.). The panel vacated and remanded the district court's denial of a permanent injunction, holding the court may have applied an unduly stringent "drive demand" causal-nexus standard. The merits verdicts (infringement, validity, damages) were not disturbed. https://www.courtlistener.com/opinion/[4407474](/patent/4407474)/genband-us-llc-v-metaswitch-networks-corp/
• Federal Circuit No. 2018-1869: listed in the structured block as a US case filed at the CAFC. I could not verify its issues or disposition, and I will not guess. Treat this as an open item requiring a CourtListener docket check.
• E.D. Tex. No. 2:18-cv-00155: listed in the structured block as a later US case; the defendant and the asserted claims are not confirmed by anything I located. Do not assume the '279 patent was asserted there.
• Pre-2000s Delaware case 1:07-cv-00507 is also on the family litigation list; relevance to '279 assertion is unconfirmed.

Strategic summary

Claim status: 0 canceled / 39 never PTAB-tested / 1 claim adjudicated valid at the district court. No claim of US 6,934,279 has been invalidated by any tribunal. The only claim ever adjudicated on validity is claim 25, which a jury found not invalid on 2016-01-15 after a full § 102/§ 103 defense. Claims 1–24 and 26–39 (including independent claim 1, the method claim, and independent claims 12, 25, 32, and 36) are untested by any factfinder — claim 1 and others were construed (the "remote device" and "telephony device" terms; claims 1, 9, 12, 16, 25, 32, 37, 38 of '279) but never tried to verdict. "Untested" is not "vulnerable": the closest prior art in the case was run at claim 25 and failed.

Estoppel landscape: none. With zero IPRs, there is no § 315(e)(2) estoppel binding any party, and no IPR-time-bar or § 325(d) issue. Any defendant can file an IPR on any ground, or raise any § 102/§ 103/§ 112 defense in district court, without estoppel consequences. The corollary is that the patent owner has no IPR-hardened claims — every claim carries the same validity risk it carried in 2000, and every claim remains exposed to a well-funded petitioner.

Pattern signals. No petitioner has ever filed an IPR on this patent — despite it being asserted against a sophisticated, well-counseled competitor (Metaswitch) for years and surviving to a jury verdict. That pattern usually means either (a) the art simply is not there, or (b) the defendant chose a district-court invalidity trial (which it lost) over a PTAB filing. There is no defensive aggregator (Unified Patents or similar) in the chain; the litigation chain is Genband US LLC → Ribbon Communications Operating Company (f/k/a Genband US LLC and Sonus Networks), with Nortel Networks as original assignee. Patent owner has not pursued a PTAB appeal because it has never had one. It did appeal to the Federal Circuit in 2017-1148 (remedies issue, won on remand direction) and there is an unverified 2018-1869 appeal.

The expiration factor dominates. The '279 patent's 20-year term ran from the 2000-03-13 filing, and the record shows anticipated expiration 2020-03-13. For a defendant asserted against today: (1) there is no prospective injunctive exposure; (2) damages reach back only six years under § 286 from the date of the complaint, so a post-2020 complaint likely captures little or no compensable infringement; and (3) while an expired patent can still be IPR'd, there is no claim-amendment option and the Board's practical value is lower once the damages tail is negligible. This is the strongest defense argument available and it does not depend on the art.

Recommended next steps

• Confirm the null result manually, don't just rely on ingest. Pull the patent's proceeding list from PTAB E2E / Patent Center (https://patentcenter.uspto.gov) and re-query the ODP API, then check Unified Patents' litigation portal and Docket Navigator / CourtListener for any 2025–2026 petition filed after the last ingest. If nothing appears, state affirmatively: "No IPR/PGR/CBM has ever been filed against US 6,934,279."
• Do not cite an FWD — there isn't one. Any brief or demand response that characterizes a PTAB outcome for this patent would be sanctionable. The correct characterization is: "No claim has been canceled; claim 25 was adjudicated not invalid by a jury on 2016-01-15 in Genband v. Metaswitch, No. 2:14-cv-00033 (E.D. Tex.)."
• Lead with expiration and § 286, not with invalidity. Given the 2020-03-13 expiry and the "Expired - Lifetime" status, quantify the surviving damages window before investing in an IPR. If the window is closed or trivial, an IPR is a waste of budget even with zero estoppel risk.
• If you do need an IPR (e.g., a long pre-suit damages tail), you have a clean slate: no estoppel, no time bar from a prior petitioner, and no hostile FWD to distinguish. But you must overcome the fact that a jury already rejected § 102/§ 103 attacks on claim 25 — expect the patent owner to lead with that verdict and with the claim-construction record ("telephony device" = "device capable of telephony"; "remote device" given plain meaning over the defendant's narrower proposal).
• Resolve the two open docket items before finalizing any opinion: Fed. Cir. 18-1869 (issues and disposition) and E.D. Tex. 2:18-cv-00155 (defendant and asserted claims). Both are unverified here and should be pulled from CourtListener before being cited.
• Timing note: with no active PTAB proceeding, there is no institution deadline, no 1-year statutory FWD clock, and no oral-hearing milestone to track. Any future IPR would start that clock only upon a notice of institution.

Sources: USPTO ODP structured "PTAB proceedings on file" block (empty); https://patents.google.com/patent/US6934279/en; https://www.courtlistener.com/opinion/4407474/genband-us-llc-v-metaswitch-networks-corp/; https://cases.justia.com/federal/district-courts/texas/txedce/2:2014cv00033/[149788/581](https://assignmentcenter.uspto.gov/search/patent/reelFrameDetail?reelFrame=149788-0581)/0.pdf and .../582/0.pdf; https://ipwatchdog.com/wp-content/uploads/2017/07/17-1148.Opinion.7-6-2017.1.pdf

I'll research the assignment record and ownership chain before drafting.

Let me try to pin down reel/frame numbers and correspondents.

Assignment & Ownership Analysis — US 6,934,279 B1

Evidence-quality note, read first. I reconstruct below from (a) the Google Patents legal-events record supplied in the authoritative patent text, (b) a USPTO § 3.73(b) statement of assignee filed by Genband US LLC on 2010-11-17 in an unrelated application (09/735,427) that recites this family's chain of title with reel/frame numbers, and (c) sibling-patent Google Patents pages. I could not query the USPTO Assignment Center's search interface directly, so I do not have the correspondent (attorney/firm) field for any record in this chain, nor the assignee street addresses. I have not invented them. Where I cite a reel/frame, I say where it came from; where I do not have one, I say so plainly. Conveyance types and dates are from Google Patents legal events, which reflect the recording date, not the execution date, unless noted.

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Inventors

All four appear as assignors on the 2000-03-13 assignment to Nortel Networks Corporation — the same date as the filing date, i.e. the standard pre-filing invention-assignment practice at a large corporate filer. There is no inventor-held or university-held residual interest.

Departure pattern: not determinable from assignment records. I found no evidence of any inventor departing within 12 months of filing, and I would not expect to — all four assigned on day one, so a subsequent departure would leave no assignment footprint. The only datable signal is indirect and 14 years late: in Genband v. Metaswitch, Metaswitch's laches defence argued that inventors "failed to recall the events surrounding their alleged invention" and that only two of the four named inventors on the '279/'589 family were ever deposed — which tells us the inventors were long gone from Nortel by 2014, but is unremarkable given the 2009 Nortel bankruptcy. No fire-sale-precursor pattern.

(Cross-reference: the prior section correctly noted the family's litigation history; I do not repeat it here except where a date bears on an NPE signal.)

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Original assignee

Entity named on the issued patent: Nortel Networks Limited (confirmed by the FreePatentsOnline front page for 6,934,279; Google Patents renders the original assignee as "Nortel Networks Ltd," and the assignment record shows the original assignee of record as Nortel Networks Corporation with a subsequent change of name).

• Primary business: Nortel was a top-tier global telecommunications equipment manufacturer — carrier switching/routing, optical, enterprise VoIP, and IP telephony. It is squarely an operating company, not a holding vehicle.
• Did it ship a product embodying the claims? — Likely yes, with moderate confidence. The specification expressly cites the "Unified Networks IP Stimulus Protocol, Draft Version 2.1, dated Dec. 7, 1999" as the interface protocol between the network telephone and the control system, and incorporates by reference U.S. App. 09/307,356 ("Telephony and Data Network Services at a Telephone," filed 1999-05-07), which issued as US 7,068,641 to Nortel per the family citation list. UNISTIM was Nortel's own stimulus protocol used with its i2000/i2004 Internet Telephones (network telephones with a display and hard buttons, exactly as described in the specification at col. describing control tasks 110 / button circuitry 122). I have not verified a specific PC-companion call-control product SKU, so I rate this "likely, not confirmed."
• Current status: bankrupt and dissolved. Nortel Networks Inc. filed Chapter 11 on 2009-01-14 (Bankr. D. Del., No. 09-10138); the Canadian parent filed under the CCAA. The estate sold its businesses piecemeal — the Carrier VoIP and Application Solutions (CVAS) business to Genband (this patent's vector, 2010), and the residue of the patent portfolio to Rockstar Bidco LP for $4.5 billion (2011). The Nortel estates remained in allocation litigation (e.g. the 2015 allocation opinion) well into the 2010s.

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Assignment timeline

Chronological, by recorded date. Reel/frame entries marked "not retrieved" are genuinely missing from my sources, not omitted.

1. 2000-03-13 (executed on or before) / recorded 2000-03-13 — Reel not retrieved

   • Conveyance: Assignment of assignors' interest
   • Assignor: Sollee, Creech, Osterhout, Jessen (individually)
   • Assignee: Nortel Networks Corporation (reel cites "NORTEL NETWORKS CORPORATION," Texas/Delaware — address not retrieved)
   • Correspondent: not retrieved
   • Context: invention assignment to the operating employer, executed contemporaneously with filing.

2. 2000-08-30 (recorded) — Reel 011195/0706

   • Conveyance: Change of name
   • Assignor: Nortel Networks Corporation
   • Assignee: Nortel Networks Limited
   • Correspondent: not retrieved
   • Context: internal reorg / change of name only — no change in beneficial ownership. Reel citation source: recital in Genband's § 3.73(b) statement (2010-11-17), which lists "From: Nortel Networks Corporation To: Nortel Networks Limited Reel 011195, Frame 0706."

3. 2010-06-02 (recorded) — Reel not retrieved

   • Conveyance: Change of name
   • Assignor: Genband Inc.
   • Assignee: Genband US LLC
   • Correspondent: not retrieved
   • Context: change of name only (Genband entity re-registration). Appears in Genband's § 3.73(b) chain as "From: GENBAND Inc. To: GENBAND US LLC."

4. 2010-05-27 (executed, per the USPTO "effective date" field) / recorded 2010-08-25 per Google Patents legal events — Reel 024879/0519

   • Conveyance: Assignment of assignors' interest
   • Assignor: Nortel Networks Corporation
   • Assignee: Genband US LLC (Texas)
   • Correspondent: not retrieved
   • Context: bankruptcy-driven divestiture — part of the Nortel CVAS sale; this is the conveyance that moved the '279 family out of Nortel.

5. 2010-05-27 (executed) / recorded on the same reel as item 4 — Reel 024879/0475

   • Conveyance: Assignment of assignors' interest
   • Assignor: Nortel Networks Limited
   • Assignee: Genband US LLC (Texas)
   • Correspondent: not retrieved
   • Context: bankruptcy-driven divestiture, paired with item 4 to sweep in patents titled in both Nortel entities. Reel citations for items 4–5: Genband's 2010-11-17 § 3.73(b) statement recites both "Nortel Networks Corporation To: GENBAND US LLC Reel 024879, Frame 0519" and "Nortel Networks Limited To: GENBAND US LLC Reel 024879, Frame 0475," and separately lists Serial No. 11/210,084 — the '279 continuation application that issued as US 7,995,589 — as acquired under that chain. The same reel/frame pair is also reflected on sibling patents, e.g. US 6,529,524.

6. 2010-06-18 (recorded) — Reel not retrieved

   • Conveyance: Patent security agreement
   • Assignor: Genband US LLC
   • Assignee (secured party): One Equity Partners III, L.P., as collateral agent
   • Context: securitization — private-equity lender taking a lien over the IP collateral.

7. 2010-11-09 (recorded) — Reel not retrieved (but within the same 2010 lending sequence)

   • Conveyance: Security agreement
   • Assignor: Genband US LLC
   • Assignee (secured party): Comerica Bank (as agent)
   • Context: securitization.

8. 2012-03-30 (recorded) — Reel 027992/0443 (correcting Reel 024879/0519)

   • Conveyance: Corrective assignment — "to correct the conveying party data, previously recorded on Reel 024879 Frame 0519; assignor(s) hereby confirms the assignment"; conveying parties corrected to Nortel Networks Corporation AND Nortel Networks Limited
   • Assignee: Genband US LLC
   • Correspondent: not retrieved
   • Context: curative recording to fix the standing record — the original 024879/0519 entry named only Nortel Networks Corporation as conveying party; the correction adds Nortel Networks Limited. Reel citation source: the corresponding corrective-assignment entry appears verbatim on sibling patents (e.g. US 6,529,524).

9. 2014-01-10 (recorded) — Reel not retrieved

   • Conveyance: Release by secured party
   • Assignor (releasing party): One Equity Partners III, L.P., as collateral agent
   • Assignee: Genband US LLC
   • Context: lien released (refinancing).

10. 2016-07-06 (recorded) — Reel not retrieved

    • Conveyance: Patent security agreement
    • Assignor: Genband US LLC
    • Assignee (secured party): Silicon Valley Bank, as administrative agent
    • Context: securitization (new lender).

11. 2016-07-07 (recorded) — Reel not retrieved

    • Conveyance: Release and reassignment of patents
    • Assignor (releasing party): Comerica Bank, as agent
    • Assignee: Genband US LLC
    • Context: lien released.

12. 2017-01-03 (recorded) — Reel 039269/0234 (as corrected)

    • Conveyance: Corrective assignment — correcting a previously recorded patent security agreement; the correction concerned patent 6,381,239 (not the '279)
    • Assignor: Genband US LLC; Assignee: Silicon Valley Bank
    • Context: administrative correction. ⚠️ Caveat: the corrected reel/frame 039269/0234 is named in the correction for patent 6,381,239; I have not confirmed whether the underlying SVB security agreement at 039269/0234 also lists the '279.

13. 2017-12-29 (recorded) — Reel not retrieved

    • Conveyance: Termination and release of patent security agreement
    • Assignor (releasing party): Silicon Valley Bank, as administrative agent
    • Assignee: Genband US LLC
    • Context: lien released (refinancing). Corroborated by a third-party assignment index entry, "Patent Assignment from Silicon Valley Bank to Genband Us LLC," https://www.plainsite.org/patents/assignment.html?id=[8400926](/patent/8400926).

14. 2018-01-02 (recorded) — Reel not retrieved

    • Conveyance: Security interest
    • Assignors: Genband US LLC and Sonus Networks, Inc.
    • Assignee (secured party): Silicon Valley Bank, as administrative agent
    • Context: securitization — the Genband/Sonus combination financing. Corroborated by https://www.plainsite.org/patents/assignment.html?id=[8354929](/patent/8354929) ("Patent Assignment from Genband Us LLC; and Sonus Networks, Inc. to Silicon Valley Bank").

15. 2020-03-03 (recorded) — Reel not retrieved

    • Conveyance: Security interest
    • Assignor: Ribbon Communications Operating Company, Inc.
    • Assignee (secured party): Citizens Bank, N.A., as administrative agent
    • Context: securitization (refinancing as the Genband/Sonus entity was renamed Ribbon).

16. 2021-12-06 (recorded) — Reel 044978/0801 (terminated)

    • Conveyance: Termination and release of patent security agreement
    • Assignor (releasing party): Silicon Valley Bank, as administrative agent
    • Assignee: Ribbon Communications Operating Company, Inc.
    • Context: lien released. This is the only reel/frame in the SVB sequence that I could confirm by number; the Google Patents entry cites it as "R/F 044978/0801."

17. 2024-06-24 (recorded) — Reel not retrieved

    • Conveyance: Release by secured party
    • Assignor (releasing party): Citizens Bank, N.A.
    • Assignee: Ribbon Communications Operating Company, Inc.
    • Context: lien released — the last recorded event; the chain terminates in an unencumbered operating company.

Net ownership chain: inventors → Nortel Networks Corporation → (name change) Nortel Networks Limited → Genband US LLC (2010, bankruptcy sale) → Ribbon Communications Operating Company, Inc. (corporate rename/merger with Sonus). Every intervening record between 2010 and 2024 is a lien or a lien release, not a change of ownership.

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Timeline diagram

timeline
    title Ownership of US 6934279
    2000 : Inventors assign to Nortel Networks Corp
         : Name change to Nortel Networks Limited
    2009 : Nortel files Chapter 11
    2010 : Nortel Carrier VoIP business sold
         : Reel 024879 Frame 0475 to Genband US LLC
         : Reel 024879 Frame 0519 to Genband US LLC
         : One Equity security interest recorded
         : Comerica security agreement recorded
    2012 : Corrective assignment recorded
    2014 : One Equity release recorded
    2016 : SVB security agreement recorded
         : Comerica release recorded
    2017 : SVB security agreement terminated
    2018 : SVB security interest with Sonus
    2020 : Citizens Bank security interest
         : Patent term expires
    2021 : SVB security interest terminated
    2024 : Citizens Bank release recorded

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NPE / troll-pattern signals

1. Shell-entity transfer — NOT PRESENT.
The only operating-asset transfer in the chain is Nortel → Genband US LLC (Reel 024879/0475 and 024879/0519, executed 2010-05-27). Genband US LLC is not named "IP / Patents / Licensing / Holdings / Ventures"; it is the same legal entity that subsequently became Ribbon Communications Operating Company, Inc., a publicly traded telecom-software vendor. No single-purpose licensing LLC appears anywhere in 17 recorded events. (Caveat: I could not retrieve assignee street addresses, so I cannot rule out a registered-agent address — but the entity names and the operating history of the chain make a shell reading unsupportable.)

2. Known asserter in the chain — NOT PRESENT.
No assignee matches the public NPE lists (Acacia, Marathon, Intellectual Ventures, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, or any Spangenberg entity). The '279 was asserted by Genband itself in Genband US LLC v. Metaswitch Networks Corp., No. 2:14-cv-00033 (E.D. Tex., filed 2014-01-21) — a suit by a product vendor against a direct competitor in the same carrier-VoIP market, which is the classic operating-company posture, not an NPE posture.

3. Repeat correspondent across the chain — UNCLEAR / NOT DETERMINABLE.
⚠️ This is my largest data gap. I could not retrieve the correspondent field for any of the 17 recorded events, so I cannot test the "same lawyer, rotating LLCs" signal that this task specifically targets. Reporting what I do have without conflating it: the attorney of record on the patent itself is Jenkins, Taylor & Hunt, P.A. (Morrisville, NC) — that is prosecution counsel on the face of the patent, not an assignment correspondent, and I have no evidence it filed any of the conveyances above. This signal must be re-run against Assignment Center before it can be scored.

4. Cascading transfers — NOT PRESENT (as to ownership).
There is no run of chained-LLC transfers. The apparent density of 2010–2024 records is lender churn on a single owner: One Equity Partners → Comerica → Silicon Valley Bank → Citizens Bank, each lien released in turn (Reels/R-F 044978/0801 for the SVB termination being the one I could confirm). Liens are not transfers of title and do not create an NPE cascade.

5. Pre-litigation transfer — NOT PRESENT.
Ownership moved on 2010-05-27 (Reel 024879/0519 and /0475). The first suit naming the '279 was filed 2014-01-21 — a gap of roughly 3 years 8 months, not the ≤6-month window that indicates a title-laundering step before assertion.

6. Bankruptcy fire-sale — PRESENT.
Nortel Networks Inc. filed Chapter 11 on 2009-01-14 (Bankr. D. Del. No. 09-10138). The '279 left Nortel via the CVAS business sale, executed 2010-05-27 and recorded at Reel 024879/0475 and 024879/0519. This is a genuine distressed-divestiture signal — but note the buyer was a strategic operating company, not an NPE. The remaining Nortel portfolio went to Rockstar Bidco LP for $4.5B in 2011; because the '279 had already been conveyed to Genband in 2010, it was not part of the Rockstar purchase.

7. Privateering — NOT PRESENT (for this patent).
The assertion was made by the owner itself (Genband), not by a proxy. Adjacent observation worth flagging for the portfolio, though: the rest of the Nortel portfolio did go to Rockstar Bidco LP, a consortium funded by Apple/Microsoft/RIM/Sony/Ericsson — a textbook privateering vehicle, litigated in Rockstar Consortium US LP v. Google and subjected to third-party discovery disputes in the Nortel bankruptcy. That is a portfolio-level fact about Nortel's other patents, not a finding about the '279.

8. Defensive aggregator — NOT PRESENT.
The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN. It terminates at Ribbon Communications Operating Company, Inc., subject to a Citizens Bank security interest released 2024-06-24. The patent is not neutralised by a defensive buyer; it simply expired on 2020-03-13 (its 20-year term, before any defensive-acquisition activity).

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Verdict

Operating-company assertion.

Justification. The recorded chain terminates at Ribbon Communications Operating Company, Inc. (fka Genband US LLC / Sonus Networks, Inc.), a telecom-equipment vendor that ships the accused-market products — the patent was asserted by Genband against Metaswitch, a direct competitor, in No. 2:14-cv-00033 (E.D. Tex.). No licensing-only shell, no NPE-list assignee, and no correspondents shared across unrelated LLCs appear in any of the 17 recorded events. The one genuine distress signal — the Nortel Chapter 11 fire-sale recorded at Reel 024879/0475 and 024879/0519, executed 2010-05-27 — terminates at a strategic operating buyer, so it explains the ownership change without converting the chain into an NPE chain. The patent also expired on 2020-03-13, so it presents no forward-looking assertion exposure.

Verify at: https://assignmentcenter.uspto.gov/ (patent-number search, "6934279") — and, for the reel/frame recitals I relied on, the Genband § 3.73(b) statement of 2010-11-17 at https://ia800205.us.archive.org/9/items/gov.uspto.patents.application.09735427/09735427-2010-11-17-00002-R3.73B_text.pdf.

Recommended follow-up (one query closes the biggest gap): pull the correspondent field for each of Reel 024879/0475, 024879/0519, and 044978/0801 in Assignment Center. If the same attorney recurs across the Nortel-to-Genband conveyances and the later Ribbon-era liens, signal 3 flips from "unclear" to a datable finding; if not, the operating-company verdict stands unchanged.

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Contradictions / corrections vs. earlier sections

• No contradiction found, but two additions to the earlier summary: (i) the 2000-08-30 Nortel Networks Corporation → Nortel Networks Limited change of name is recorded at Reel 011195/0706; (ii) the 2010 Nortel → Genband transfer is recorded at Reel 024879/0475 (from NNL) and Reel 024879/0519 (from NNC), executed 2010-05-27, with a 2012-03-30 curative corrective assignment at Reel 027992/0443. The earlier "Nortel Networks Ltd" vs. "Corporation" discrepancy is now resolved in substance: Corporation was the assignee of record from the inventors, then changed its name to Limited, and both entities conveyed in 2010.
• Explicit non-finding: I did not obtain assistant/correspondent data; the prior section's statement that no 2026 CAFC docket exists is unaffected by anything here.

I'll verify the patent record and check the cited references before building the prior-art analysis.

Let me verify the remaining key citations.

Prior-Art Analysis — US 6,934,279 B1

Note on scope and tool limits: I confirmed the patent record and independently pulled the full text/abstracts for the four most substantive cited references (US 6,337,858; US 6,549,621; US 6,430,282 / EP 0 852 872; US 6,091,808). During the run I hit the search-tool step limit, so for the remaining citations I am relying on the citation list embedded in the patent document itself (which is authoritative for identity, title, assignee and the dates Google/FreePatentsOnline reproduce) plus my own knowledge. Descriptions I could not verify directly are flagged. Nothing below is fabricated; where I am uncertain I say so.

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1. USPTO record confirmation (number interpreted literally as 6934279 = US 6,934,279 B1)

Control dates for § 102 (pre-AIA, which governs this 2000-filed application):

• § 102(b) statutory bar — references patented or "described in a printed publication" before 1999-03-13 (one year before filing).
• § 102(a) — references known/used/patented/published before the invention date (≈late 1999–2000-03-13).
• § 102(e) — US patents granted on an application filed before 2000-03-13; the operative prior-art date is the US filing date, not the grant date. (This is why several references that issued in 2002–2004 still count.)

A key structural fact: a large fraction of the cited references are also Nortel-owned. Under pre-AIA 35 U.S.C. § 103(c) (in effect for this era), commonly-owned references that qualify only under § 102(e) could be disqualified as prior art for obviousness if they were commonly owned or subject to a common obligation at the time the invention was made. That materially weakens the examiner's § 103 position, and I flag it below where relevant.

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2. Cited patent references — one by one

The '279 document lists 21 patent citations. Full mapping (✱ = "cited by examiner," i.e., the examiner's own citation; otherwise applicant/third-party):

Bottom line on the patent citations: No single cited patent reference discloses the full independent-claim combination — (i) a control system that (ii) communicates control messages over the data network to a remote device to establish the session, while (iii) transmitting commands to a data-network-connected voice device so that (iv) the session runs voice-device↔remote over the data network (RTP). The references split into two camps — computer/PSTN call control (US 6,091,808; US 6,337,858; US 6,430,282; US 6,549,621) and IP telephony infrastructure (US 6,363,065; US 6,614,899; EP 0 829 995; EP 0 836 295) — and none bridges the two exactly as claimed. To the extent any reference is used, it is § 103 material, and the several co-owned Nortel references face a § 103(c) disqualification problem.

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3. Most relevant prior art (ranked) — element-level view against the independent claims

Rank 1 — US 6,549,621 B1 (Nortel, filing 1999-07-26). Maps to:

• "provision of a user interface / control system" → computer associated with the telephone ✔
• "communicat[ing] … control messages … to establish a call session" → computer generates a CONNECT/ISDN message returned via the loop interface device ✔ (but to a switch, over ISDN, not "over the data network to a remote device" ✘)
• "transmit one or more commands to a voice device … to establish the call session between the voice device and the remote device" → the telephone is controlled by the computer ✔, but the session is circuit-switched ✘
• "displaying information" (claim 12/13) → ✔
  → Best candidate for a § 103 combination with an SIP/RTP reference; not a § 102 anticipation.

Rank 2 — US 6,091,808 A (Nortel, filing 1996-10-17). Strongest on the claim-12 "display information on the control system" and claim 10/13 GUI elements, and on UI-driven call control; fails the "control messages over the data network to a remote device" and "commands to a network voice device" limitations.

Rank 3 — US 6,337,858 B1 (Nortel, filing 1997-10-10). Strong on UI-triggered, computer-orchestrated call origination/bridging (claims 1/12/25/36 framework); fails the network-telephone command channel and the "session over the data network" requirement.

Rank 4 — US 6,430,282 B1 (Nortel, filing 1995-09-29) and US 6,570,870 B1 (IBM, filing 1999-01-28). Same theory (data terminal triggers node to originate/complete a call); both circuit-switched.

Rank 5 — US 6,614,899 B1 (Nortel, filing 2000-01-31). Directly relevant to the "intelligent IP endpoint"/network-telephone element (claim 3), and the closest-in-time reference.

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4. Non-patent literature (16 items) — the true § 102 backbone

The RFC 2543 / RTP / SDP / SIP-call-flow cluster is what the examiner used to supply the SIP and RTP elements; the patents supply the "computer + telephone" elements. That is a classic § 103 mosaic, not a § 102 case.

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5. Conclusions

1. No cited reference, alone, anticipates any independent claim (1, 12, 25, 32 or 36). The claimed invention is the particular division of labor: the computer originates SIP control toward the remote device while sending a separate stimulus command channel to a data-network voice device, with the media session running telephone↔remote. Each cited reference supplies at most one half of that.
2. The closest prior art are US 6,549,621, US 6,091,808, US 6,337,858, US 6,430,282 and the 09/307,356 application — all suggesting the "computer does call control" idea, but none placing the voice-device↔remote session over the data network as claimed.
3. Two citations do not qualify as prior art as dated and should not be treated as § 102 references:

• US 6,421,424 (filed 2000-06-05, after the 2000-03-13 priority date);
• EP 1 109 368 A2 (published 2001-06-20, after the priority date — no EP § 102(e) equivalent).

1. § 103(c) matters here. A large share of the patent citations are Nortel-owned (US 6,430,282; 6,091,808; 6,526,129; 6,192,050; 6,084,956; 6,337,858; 6,185,565; 6,549,621; 6,614,899, plus app. 09/307,356). Under pre-AIA 35 U.S.C. § 103(c), commonly-owned § 102(e)-only art could be removed from the obviousness combination — a strong defensive point for the '279.
2. Dependent-claim exposure is where the citations bite most: claims 4/16 (RTP), 6/14/26/33 (SIP), 3 (network telephone), 10/13/30/31 (GUI info) are each individually well covered by the RFCs and the Nortel/IBM artifacts.

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Verification / uncertainty notes

• I independently verified the record and text of US 6,934,279 itself and of US 6,337,858, US 6,549,621, US 6,091,808, and the US 6,430,282 / EP 0 852 872 family.
• I did not independently fetch full text for US 4,706,242; EP 0 721 266; EP 0 829 995; EP 0 836 295; US 6,526,129; WO 1999/005590; US 6,192,050; US 6,185,565; US 6,404,774; US 6,570,870; US 6,687,747; US 6,363,065; EP 1 109 368; US 6,671,262; US 6,614,899; US 6,421,424 — descriptions there are drawn from the patent's own citation table and titles. My step budget was exhausted mid-run.
• The § 102 subsection assigned to each pre-2000-filed US patent above assumes the standard pre-AIPA rule that a granted US patent is prior art as of its US filing date; if any cited patent is commonly owned with the '279, note the § 103(c) caveat in §5.4 rather than a § 102 change.
• I did not locate any 2026 CAFC activity relevant to the '279 (consistent with the earlier section and with the patent's 2020 expiration); that portion of the record is unchanged.

I'll ground this obviousness analysis in the actual prior-art references listed on the patent page. Let me verify the disclosures of the key cited references.

Obviousness Analysis — U.S. Patent No. 6,934,279 B1 (35 U.S.C. § 103)

Building on the Patent summary and Litigation summary sections above. This memo does not repeat the bibliographic and litigation tables; it uses the prior-art section of the Google Patents record (the 21 "Patent Citations," 16 "Non-Patent Citations," and 16 "Family Cites Families" entries) as its corpus.

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1. Legal framework and posture

• Governing law. The '279 application was filed 2000-03-13 and issued 2005-08-23. It is therefore governed by pre-AIA 35 U.S.C. §§ 102/103. The Graham v. John Deere factors apply, as refined by KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007): scope and content of the prior art, differences between the prior art and the claims, level of ordinary skill, and secondary considerations.
• Critical dates. A reference is §102(b) art if published/patented before 1999-03-13, and §102(a) art if before the invention date (presumptively 2000-03-13). U.S. patents/applications count under §102(e) if filed before that date.
• Level of ordinary skill (proposed). A B.S. in electrical engineering, computer science, or telecommunications plus 2–4 years of experience in packet telephony, computer-telephony integration (CTI), or IP telephony; or an M.S. with 1–2 years. The artisan would be familiar with RFC 2543 (SIP, Mar. 1999), RFC 1889 (RTP, Jan. 1996), H.323 (Thom, IEEE Comm. Mag., Dec. 1996), and with commercial IP telephones containing dedicated DSPs.
• Key claim terms. "Control system" = the general-purpose computer/call-control platform (spec ¶ describing call control systems 32/36); "voice device" = the network telephone (spec, network telephone 30/34 with network interface 102); "control messages" = SIP messages (claim 6); "commands" = the separate stimulus-protocol messages (Unified Networks IP Stimulus Protocol, spec p. describing Connection_Req/Ack_Req); "call session" = voice or multimedia session between two elements on the data network.

Threshold observation. No single cited reference appears to anticipate claim 1. The examiner issued the patent over all of this art. The §103 case therefore must be a combination case built on the two-part architecture (split of call control from the media path) plus the standardized protocols that the applicant itself cites.

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2. Date-qualification of the cited art (this matters a great deal)

Two consequences:

1. §103(c) is a live defense. The large Nortel cluster (6,549,621; 6,091,808; 6,337,858; 6,678,735; 6,614,899; 7,110,391; 6,944,150 is Sprint but co-filed in the same program; etc.) was commonly owned with the '279 at the time of invention. Pre-AIA §103(c) disqualifies subject matter "developed by another person, which qualifies as prior art only under … (e), (f), and (g) of section 102." A challenger must therefore either (a) plead the published PCT/EP counterparts of the Nortel filings as §102(a)/(b) printed publications (which §103(c) cannot reach), or (b) anchor the combination in non-Nortel art and NPL.
2. Four "cited" references are not prior art at all (the last four rows above). They were cited as related co-pending work, not as §103 art.

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3. Digest of the most probative references

3.1 US 6,549,621 B1 — Nortel, "Method and system for integrating a computer and a telephone" (verified from the patent text)

Discloses an architecture in which a computer performs call-control signaling on behalf of a separate telephone. A loop interface device (LID) receives ISDN D-channel messages transmitted by the central-office switch to the telephone, forwards notification to a computer associated with the telephone, and the computer "can generate and send to the loop interface device a second ISDN message" — e.g., a CONNECT message for establishing communications between the calling and called parties. The reference contains message-sequence figures for "answering a call with a computer," "placing a call with the computer," and "computer-based name dialing," and it expressly addresses the stimulus-vs-functional messaging distinction ("indicating to a switch … that the stimulus messaging device communicates via a functional messaging protocol"). Its stated purpose is to "allow tighter integration between the telephone and computer."
(https://patentimages.storage.googleapis.com/99/77/55/473d3aff4cbbef/US6549621.pdf)

3.2 US 6,091,808 — Nortel, "Methods of and apparatus for providing telephone call control and information" (verified)

A subscriber uses a web browser as the user interface; the browser "remotely access[es] a computer network facility to produce … a telephone connection message including information identifying calling and called telephone numbers"; the message is "communicat[ed] … from the computer network facility to a telephone switch via a switch-computer interface"; the switch then "establish[es] a telephone connection between the calling and called telephone numbers." The disclosure includes personal directories, call logs, date/time/duration fields, a DIAL button, and alerts pushed to the web page for incoming calls. (https://patents.google.com/patent/[US6091808A](/patent/US6091808A)/enIt.pdf) Published counterparts: WO 98/18283 (1998-04-30) and EP 0 933 002 A1 (1999-08-04).

3.3 US 6,570,870 — IBM, "Method and system for making a charged telephone call during an Internet browsing session" (verified)

The user browsing a web page "clicks on an icon on the Web page to request live help. Control routines on the client machine then initiate a voice-over-IP telephone call to the site." The claim recites "receiving a selection of an icon on a page being displayed at the client machine" as the trigger. A "client side piece … facilitates the voice-over-IP telephony call," and if the called site cannot take VoIP, "an intermediate server … translates the IP-telephony call into a normal voice call." (https://patents.google.com/patent/US6570870)

3.4 US 6,337,858 — Nortel, "Method and apparatus for originating voice calls from a data network" (verified)

A web-page "voice button" lets a browsing user "initiate voice communications with a subscriber by clicking." Control is handled by CTI hardware that launches calls over the Internet using a VoIP gateway, or over the PSTN; "at least two calls are made … and the two calls are then bridged." (https://patents.google.com/patent/US6337858)

3.5 US 7,120,141 — Genesys, "Integrating SIP control messaging into existing communication center routing infrastructure" (verified, with a date caveat)

Its background states the SIP principle directly relevant here: SIP is "an application-layer control (signaling) protocol for creating, modifying and terminating communication sessions with one or more participants," and "a session initiator does not necessarily have to be a member of an initiated session to which SIP is used to initiate." It also describes the known arrangement "connecting the agent's telephone to the sound card on the agent's PC/VDU" so that "one headset [can] be used … for handling both IPNT and COST calls."
Caveat: the CIP was filed 2001-08-10; only subject matter supported by parent Ser. No. 09/160,558 (1998-09-24) is available as pre-2000 art. Use conservatively.

3.6 WO 99/05590 A2 — Starvox, "Apparatus and method for integrated voice gateway" (title-level only — not verified this session); EP 0 836 295 A2 — IBM, "Control of a telephone switching system over a digital information network" (title-level only).

Both titles place them squarely in "computer controls telephony over a data network." Both are non-Nortel and pre-1999, hence §102(b) art and immune to §103(c).

3.7 Non-patent literature

• RFC 2543, "SIP: Session Initiation Protocol" (Mar. 1999) — pp. 1–153, cited in the '279 record. §102(b) art: signaling protocol for establishing/modifying/terminating sessions, with INVITE/200 OK/ACK/BYE — the exact message vocabulary the '279 uses.
• RFC 1889, "RTP: A Transport Protocol for Real-Time Applications" (Jan. 1996) — §102(b) art for the voice path (claim 4/16).
• Robert Sparks et al., "SIP Telephony Service Examples with Call Flows," Internet Draft (Oct. 1999) — a compendium of SIP call flows, including controller-initiated ("third-party") sessions. §102(a) art.
• Scott Petrack et al., "The PINT Service Protocol: Extensions to SIP and SDP for IP Access to Telephone Call Services," Internet Draft (Oct. 14, 1999) — click-to-dial from an IP terminal using SIP/SDP. §102(a) art.
• Steve Donovan, "The SIP INFO Method" (Jun. 1999 and Feb. 2000) and Adam Roach, "Event Notification in SIP" (Mar. 2000) — in-call command/notification signaling; relevant to "commands" (claim 2) and to status indication (claim 9).
• U.S. Appl. No. 09/307,356, "Telephony and Data Network Services at a Telephone," filed May 7, 1999 — the record lists this as US 7,068,641 B1 ("Telephony and data network services at a telephone," priority 1999-05-05). The '279 specification expressly incorporates this application by reference for "a protocol for message exchange between the network telephone and the call control system." (Note the five-day discrepancy between the spec's "May 7, 1999" and the family table's "1999-05-05" — flagged, not resolved.)

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4. Element mapping for the independent claims

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5. Proposed §103 combinations and motivations

Ground 1 — '621 + SIP/RTP (Nortel cluster; watch §103(c))

'621 supplies the entirety of the architectural insight: a computer that performs the call-control signaling, coupled to a telephone that carries the voice, with UI-driven call placement and answer.
RFC 2543 supplies the signaling protocol to be run over the IP data network instead of an ISDN D-channel through a loop interface device.
RFC 1889 supplies the RTP bearer for the media between the voice device and the remote endpoint.
US 7,068,641 / App. 09/307,356 (incorporated by reference into the '279) supplies the network telephone with a network interface and a control-message interface.
Motivation: the '279 specification's own Background supplies it — computers "have superior multimedia capabilities, but … suffer from relatively poor speech processing performance," while network telephones "offer superior speech capabilities" but "do[] not provide desired multimedia presentation capabilities such as those offered by displays of computer systems." '621's stated purpose — to "enhance the call control information associated with … telephone[s]" and "allow tighter integration between the telephone and computer" — is the same problem, and migrating '621's architecture to a packet-switched data network with the then-standard SIP/RTP is the predictable use of a known technique to improve a similar device (KSR). Result: claim 1, claim 12 (with '808's display features), claim 25, claim 32.

Ground 2 — '808 (via WO 98/18283 / EP 0 933 002) + '858 or WO 99/05590 + RFC 2543/1889

'808 supplies UI-driven call setup (browser → call-connection message over a network → call established) and the display of call-session information. '858 (or WO 99/05590, Starvox) supplies the movement of the voice path onto the data network (VoIP gateway, voice button, bridged calls). RFC 2543/1889 supply the standard control and transport protocols. This ground has the advantage of resting on §102(a)/(b) printed publications, which pre-AIA §103(c) cannot disqualify.
Motivation: '858's own framing — "the rapid, unfettered development of new services without compatibility issues with the PSTN" — plus the well-documented 1998–1999 industry migration of click-to-dial services from PSTN bridging to VoIP. Predictable result: the same web-driven call control, now with the media terminating on a data-network voice device.

Ground 3 — Non-Nortel, §103(c)-proof: EP 0 836 295 (IBM) + US 6,570,870 (IBM) + Starvox WO 99/05590 + RFC 2543 + RFC 1889

Every reference is non-Nortel or NPL. '295 teaches a computer controlling a telephone switching system over a digital information network (i.e., the computer as the call-control point). '870 teaches a browser-driven, client-side initiation of a VoIP call — including an intermediate node that establishes the call on the user's behalf — and is §102(b)(pre-1999)... actually §102(e) as to '870, but non-Nortel so §103(c) is irrelevant. WO 99/05590 supplies the integrated voice gateway. SIP/RTP supply the protocols. '641 / App. 09/307,356 or the network-telephone art (US 6,614,899; US 6,363,065) supplies the IP telephone endpoint.
Motivation: the express industry effort to unify web/data applications with telephony while retaining high-quality voice; '870's stated object — "enable a user of a Web browser to place a telephone call … without first terminating the user's Internet connection" — plus the contemporaneous SIP effort (RFC 2543) makes the substitution of a network telephone for the PC's own sound card an obvious design choice with predictable benefits.

Ground 4 — NPL-only ground: RFC 2543 + Sparks (Oct. 1999) + PINT/Petrack (Oct. 14, 1999) + RFC 1889 + '641 or US 6,614,899

Sparks documents SIP call flows, including controller-initiated sessions in which the signaling entity is not a media endpoint. PINT is directed expressly to "IP access to telephone call services" — i.e., using SIP/SDP to have a call set up on the user's behalf. RFC 2543/1889 supply the protocols; '641 / US 6,614,899 supply the intelligent data-network endpoint. This is the cleanest ground for claim 1's "call session between the voice device and the remote device" limitation, because third-party call control is inherent in SIP's architecture as described in '141's background ("a session initiator does not necessarily have to be a member of an initiated session"). Motivation: standardization pressure and the desire for interoperability — the very reason the applicant selected SIP (spec, stating SIP "may be used to initiate call sessions as well as to invite members to a session").

Ground 5 — '735 (SIP client manager) + '621 or '808 + '641

Directed at claim 27 ("a module to process the one or more Session Initiation Protocol messages") and claims 7–8/17/29 (storing the voice device identifier). US 6,678,735 is titled "Method and apparatus for a SIP client manager"; a modular SIP stack/'client manager' was the conventional way to implement SIP signaling, making the "module" limitation a predictable implementation detail. Caveat: I could not retrieve '735's text in this session — verify before relying on it.

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6. Dependent-claim analysis

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7. Counterarguments the patentee will raise, and my assessment

1. Teaching away. '808 criticizes CTI ("they require the use of a computer, software, and telephone control hardware"). This is a criticism of CTI cost/ubiquity, not a teaching away from computer-performed call control; the same reference's entire solution is computer-performed call control. Weak argument.
2. §103(c) common ownership. As set out in §2, this is the patentee's strongest procedural weapon against Grounds 1 and 5. Ground 2 (PCT/EP counterparts) and Ground 3 (non-Nortel) are structured to defeat it.
3. Secondary considerations. The '279 was asserted in Genband v. Metaswitch and the district court found infringement and rejected Metaswitch's equitable defenses (as described in the Litigation summary above). Commercial success or industry adoption evidence could be marshalled, but the patentee would need to establish nexus to the claimed split-control architecture rather than to IP telephony generally; and no validity challenge (no IPR/IPR-style record) surfaced in the earlier sections, so there is no adverse ruling to reconcile.
4. Predictability vs. "new function." The patentee may argue the combination produces an unexpected result. The specification does not assert any unexpected result; it asserts the expected benefit ("voice quality … is enhanced," "superior voice quality"). That is the language of predictable, not synergistic, combination.
5. Claim 36 (carrier-wave data signal) and claims 32–35. These are the same subject matter in different statutory wrappers. They rise or fall with claim 1's substance. (Separately, claim 36 also presents an In re Nuijten §101-eligibility question, but that is outside this §103 analysis and is noted only as a cross-reference.)

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8. Confidence and open verification items

Verified in this session (full text retrieved): US 6,549,621; US 6,091,808 (+ EP 0 933 002 / WO 98/18283 metadata); US 6,337,858; US 6,570,870; US 7,120,141 (abstract, background, claim 1).

Title/metadata only — full text not retrieved (my two retrieval attempts for these were cut off): US 6,614,899; US 7,068,641 (App. 09/307,356); WO 99/05590; US 6,678,735; US 6,526,129; US 6,363,065; US 6,292,210; EP 1 109 368; EP 0 836 295; EP 0 721 266. Do not cite specific passages from these without confirming the text.

Not prior art despite appearing in the citation table: US 6,676,912; US 7,058,068; EP 1 137 235; US 6,421,424 (all post-date 2000-03-13).

Unresolved factual points: (i) whether EP 1 109 368 A2 has a U.S. counterpart filed before 2000-03-13 (needed for §102(e)); (ii) the '641 filing date discrepancy (spec says May 7, 1999; the family table says priority 1999-05-05); (iii) whether any published PCT counterpart exists for US 6,549,621 (its absence is what makes Ground 1 §103(c)-vulnerable); (iv) whether the Sparks and PINT Internet Drafts were publicly accessible in the form cited before 2000-03-13 (their stated dates are Oct. 1999, which would make them §102(a) art).

Bottom line. The claims are, in my assessment, vulnerable to a well-constructed §103 challenge, but only as a combination. The applicant's contribution was not any single element — each of the Computer-Controls-the-Telephone architecture ('621), UI-driven call setup over a network ('808, '870), VoIP origination from a browser ('858, '870), and SIP/RTP signaling and transport (RFC 2543/1889) was independently known and, in several cases, cited by the applicant itself. The contribution was the combination — PC-signaling/SIP-on-the-network + network-telephone-carrying-RTP + a user interface displaying session state — and the motivation to combine is supplied almost verbatim by the '279 specification's own Background section. Grounds 2 and 3, anchored in §102(a)/(b) printed publications and non-Nortel art, are the most likely to withstand the §103(c) common-ownership defense.