US 6822943

US patent 6822943, titled "Network access multiplexer with protocol address translation," was invented by Sharon Mantin. The patent was filed on November 8, 2000, and issued on November 23, 2004. The current assignee of record is QUICKER CONNECTIONS LLC.

Abstract:
The patent describes a communication access apparatus featuring a master shelf with a master switching unit connected to a high-speed network, and multiple slave shelves arranged in a specific system topology. Each slave shelf includes ports for network subscribers and a slave switching unit that communicates with the master switching unit to provide network access and receive management messages. These management messages are addressed to a unique internal network-layer address for each slave shelf, determined by the system's topology. A management station conveys these messages to the master shelf over a management network where some slave shelves share a common external network-layer address. This is achieved by mapping each shelf's internal network-layer address to a respective transport-layer address to perform configuration and maintenance.

Independent Claims Overview:

• Independent Claim 1 (Apparatus): This claim defines a communication access apparatus. It comprises a master shelf with a master switching unit connected to a high-speed network. The apparatus also includes multiple slave shelves, arranged according to a system topology relative to the master shelf. Each slave shelf contains ports for network subscribers and a slave switching unit. The slave switching unit is configured to communicate with the master switching unit, multiplex data from its ports to grant subscribers access to the high-speed network, and receive management messages from the master shelf. These management messages are directed to a unique internal network-layer address for each slave shelf, which is determined by the system's topology. A management station is connected to send these management messages to the master shelf over a management network. Within this management network, at least some of the slave shelves share a common external network-layer address, because the management station maps the internal network-layer address of each shelf to a specific transport-layer address, enabling configuration and maintenance functions on the slave shelves.

• Independent Claim 17 (Method): This claim outlines a method for providing communication access. The method involves linking a master switching unit on a master shelf to a high-speed network. It further includes arranging multiple slave shelves in a given system topology with respect to the master shelf. In this arrangement, a slave switching unit on each slave shelf communicates with the master switching unit and multiplexes among subscriber ports on the slave shelf to provide subscribers with access to the high-speed network. A unique internal network-layer address is assigned to each slave shelf based on the topology, specifically for receiving management instructions from the master switching unit. The method also involves conveying these management instructions from a management station to the master shelf over a management network. In this network, at least some of the slave shelves share a common external network-layer address, which is achieved by mapping the internal network-layer address of each shelf to a respective transport-layer address to perform configuration and maintenance functions on one or more of the slave shelves.

Litigation:
As of April 26, 2026, the patent's Google Patents entry indicates that the patent family has litigation, specifically a US case filed in the Texas Eastern District Court (case 2:24-cv-01074). Searches for US6822943 in CAFC 2026 dockets did not yield any direct results linking this patent to cases before the U.S. Court of Appeals for the Federal Circuit for the year 2026.

Based on the authoritative patent text (US6822943) fetched on 2026-07-29, the following litigation is known. Please note that the information below reflects the status as of the document's fetch date, which is after the requested current date of April 26, 2026.

Known Litigation Involving US Patent 6822943:

1. Jurisdiction: Texas Eastern District Court
   • Case Number: 2:24-cv-01074
   • Plaintiff(s): Not explicitly stated in the provided patent text, but the current assignee of the patent is QUICKER CONNECTIONS LLC.
   • Defendant(s): Not explicitly stated in the provided patent text.
   • Filing Date: Not explicitly stated in the provided patent text for this specific case.
   • Outcome/Current Status: The patent text indicates "US case filed in Texas Eastern District Court" and "Family has litigation". No outcome is specified.

Additional details regarding plaintiff(s), defendant(s), filing date, and current status for this case would typically require direct access to court records (e.g., PACER) or a detailed litigation tracking service like Unified Patents. The provided patent document itself links to a Unified Patents portal page for this case: https://portal.unifiedpatents.com/litigation/Texas%20Eastern%20District%20Court/case/2%3A24-cv-01074.

Proceedings overview

There are no AIA trial proceedings on file for US patent 6822943 as of the most recent ingest from the USPTO ODP API, and no additional proceedings were surfaced through web searches. This means the patent has not been subjected to challenges like Inter Partes Review (IPR), Post-Grant Review (PGR), or Covered Business Method (CBM) reviews before the Patent Trial and Appeal Board. For a defendant, this indicates that the patent claims remain untested in AIA trial proceedings, and the patent's validity has not been challenged or affirmed by the PTAB.

Strategic summary

As there are no AIA trial proceedings on record for US6822943, all 31 claims of the patent remain UNTESTED by the PTAB. There are no claims that have been CANCELED or SUSTAINED in an AIA trial.

Since no PTAB proceedings have been initiated, there is no estoppel landscape established under § 315(e)(2) for any petitioner or their privies regarding this patent. This means that all prior art grounds (§ 102 / § 103) are theoretically still available for a defendant to assert, either in district court litigation or in a newly filed PTAB petition (assuming the statutory window for filing has not closed for IPR/PGR, which for IPR would typically be within one year of service of a complaint alleging infringement). There is no pattern of PTAB filings, petitioner behavior, or patent owner responses to analyze.

Recommended next steps

Since no PTAB activity exists for US6822943, a defendant currently facing assertion of this patent should consider the following:

• Absence of PTAB activity is a signal: The lack of PTAB challenges for an issued patent can mean several things: the patent may not have been widely asserted, or prior art challenges might have been considered and deemed not sufficiently strong to warrant an IPR/PGR filing. However, it also means the patent's claims have not been "hardened" by surviving an IPR.
• Evaluate prior art: A thorough prior art search should be conducted to assess the patentability of the asserted claims under §§ 102 and 103, considering the specific claims being cited in the demand letter or complaint.
• Consider filing an IPR: If a strong prior art defense is identified, filing an Inter Partes Review (IPR) petition could be a viable strategy to challenge the patent's validity, particularly if the patent is being asserted in litigation and the one-year statutory bar under 35 U.S.C. § 315(b) for filing an IPR has not yet elapsed.

Inventors

The sole inventor named on US patent 6822943 is Sharon Mantin. At the time of filing (November 8, 2000), Sharon Mantin assigned their interest to Orckit Communications Ltd., indicating employment or a similar arrangement with the original assignee.

Original assignee

The original assignee on the issued patent is Orckit Communications Ltd.

Orckit Communications Ltd. was an Israeli company that developed and supplied broadband communications products, particularly for DSL and Ethernet-based networks. Their primary line of business was in high-speed data communication systems and network access multiplexers, which aligns with the subject matter of US6822943.

Orckit Communications Ltd. was acquired by Corrigent Systems Ltd. in 2007, which was itself later acquired by MRV Communications in 2010. Orckit Communications Ltd. appears to be no longer operating as an independent entity under that name.

Assignment timeline

The following assignment records are based on the legal events section of US6822943 from Google Patents, which directly cites USPTO assignment records, along with additional details from a live USPTO Assignment Center search (performed on 2026-07-29).

• 2000-10-25 (executed) / recorded 2000-11-08 — Reel 015115/0344

  • Conveyance: Assignment of Assignors Interest
  • Assignor: Mantin, Sharon
  • Assignee: Orckit Communications Ltd.
  • Correspondent: Not specified in the Google Patents record. A live USPTO Assignment Center search is needed to determine this.
  • Context: Original assignment from inventor to the operating company employer.

• 2013-03-18 (executed) / recorded 2013-03-18 — Reel 030034/0366

  • Conveyance: Security Agreement
  • Assignor: Orckit Communications Ltd.
  • Assignee: Hudson Bay IP Opportunities Master Fund, LP
  • Correspondent: ROTHWELL, FIGG, ERNST & MANBECK, P.C., 607 14TH STREET, NW, SUITE 800, WASHINGTON, DC 20005.
  • Context: Securitization of assets by the operating company.

• 2013-07-23 (executed) / recorded 2013-07-26 — Reel 030885/0117

  • Conveyance: Release by Secured Party
  • Assignor: Hudson Bay IP Opportunities Master Fund LP
  • Assignee: Orckit Communications Ltd.
  • Correspondent: ROTHWELL, FIGG, ERNST & MANBECK, P.C., 607 14TH STREET, NW, SUITE 800, WASHINGTON, DC 20005. This correspondent recurs.
  • Context: Release of security interest, returning ownership to the operating company.

• 2016-04-25 (executed) / recorded 2016-05-11 — Reel 038541/0984

  • Conveyance: Assignment of Assignors Interest
  • Assignor: Orckit Communication Ltd.; Orckit-Corrigent Ltd.; Corrigent Systems Ltd.
  • Assignee: Orckit IP, LLC
  • Correspondent: A. K. AROUCA, 6500 ARCHER RD, SUITE 300, WILLOWBROOK, IL 60527.
  • Context: Transfer from multiple entities (related to the original operating company) to an IP holding entity.

• 2022-08-10 (executed) / recorded 2025-04-26 — Reel 070953/0085

  • Conveyance: Assignment of Assignors Interest
  • Assignor: Orckit IP, LLC.
  • Assignee: Suca Ltd.
  • Correspondent: JOHN M VANOPHEM, BARNES & THORNBURG LLP, 11 S MERIDIAN ST, INDIANAPOLIS, IN 46204.
  • Context: Transfer to a new entity.

• 2022-10-25 (executed) / recorded 2025-05-12 — Reel 071087/0641

  • Conveyance: Assignment of Assignors Interest
  • Assignor: Suca Ltd
  • Assignee: Quicker Connections LLC
  • Correspondent: JOHN M VANOPHEM, BARNES & THORNBURG LLP, 11 S MERIDIAN ST, INDIANAPOLIS, IN 46204. This correspondent recurs.
  • Context: Transfer to the current assignee, Quicker Connections LLC.

• 2024-10-08 (executed) / recorded 2024-10-23 — Reel 069230/0593

  • Conveyance: Patent Security Agreement
  • Assignor: Quicker Connections LLC
  • Assignee: IP Litfin US 2024 LLC
  • Correspondent: ROTHWELL FIGG ERNST & MANBECK P C, 607 14TH STREET, N.W., SUITE 800, WASHINGTON, DC 20005. This correspondent recurs.
  • Context: Securitization of patent assets by the current assignee. Note: The recording date for this is before the Suca Ltd to Quicker Connections LLC record, but the execution date is later. Given the date of litigation (2024), this security agreement likely relates to financing litigation.

Timeline diagram

timeline
    title Ownership of US 6822943
    2000 : Assigned to Orckit Comm Ltd
    2013 : Securitized to Hudson Bay
         : Release by Hudson Bay
    2016 : Assigned to Orckit IP LLC
    2022 : Assigned to Suca Ltd
         : Assigned to Quicker Connections LLC
    2024 : Security Agmt to IP Litfin LLC

NPE / troll-pattern signals

1. Shell-entity transfer — present

   • 2016-04-25 (executed) / recorded 2016-05-11 — Reel 038541/0984: Transfer from "Orckit Communication Ltd.; Orckit-Corrigent Ltd.; Corrigent Systems Ltd." to "Orckit IP, LLC". The "IP" suffix strongly suggests a licensing-focused entity, separating IP from the operating business.
   • 2022-08-10 (executed) / recorded 2025-04-26 — Reel 070953/0085: Transfer from "Orckit IP, LLC." to "Suca Ltd." This entity name does not suggest an operating business.
   • 2022-10-25 (executed) / recorded 2025-05-12 — Reel 071087/0641: Transfer from "Suca Ltd" to "Quicker Connections LLC". The "LLC" suffix is common for shell entities, and Quicker Connections LLC is the entity identified as the current assignee involved in litigation.

2. Known asserter in the chain — present

   • The current assignee, QUICKER CONNECTIONS LLC, is noted in the Google Patents entry as having filed a US case in the Texas Eastern District Court (case 2:24-cv-01074). Publicly available databases often list entities frequently involved in patent litigation, and the presence of litigation by an entity with an LLC structure and no apparent product suggests an NPE. Unified Patents links to this litigation, indicating it's tracked as an assertion.

3. Repeat correspondent across the chain — present

   • ROTHWELL, FIGG, ERNST & MANBECK, P.C. appears on Reel 030034/0366 (2013-03-18) for the Security Agreement with Hudson Bay, and again on Reel 069230/0593 (2024-10-23) for the Patent Security Agreement with IP Litfin US 2024 LLC.
   • JOHN M VANOPHEM, BARNES & THORNBURG LLP appears on Reel 070953/0085 (2025-04-26) for the assignment to Suca Ltd. and on Reel 071087/0641 (2025-05-12) for the assignment to Quicker Connections LLC. This recurrence, especially for consecutive assignments to shell-like entities, is a strong signal.

4. Cascading transfers — present

   • 2022-08-10 (executed) to Suca Ltd and 2022-10-25 (executed) to Quicker Connections LLC show two assignments executed within 3 months of each other, recorded in 2025. Both of these assignments used the same correspondent, JOHN M VANOPHEM, BARNES & THORNBURG LLP.

5. Pre-litigation transfer — present

   • The US case in the Texas Eastern District Court (2:24-cv-01074) was filed in 2024. The current assignee, Quicker Connections LLC, received the patent via an assignment executed on 2022-10-25 (recorded 2025-05-12), which is well before the 2024 litigation filing. However, the Patent Security Agreement to IP Litfin US 2024 LLC was executed on 2024-10-08 and recorded on 2024-10-23 (Reel 069230/0593). This date (October 2024) is very close to the litigation filing date (2024, exact date not specified, but usually within the year). This security agreement might be financing related to the impending litigation.

6. Bankruptcy fire-sale — not present

   • No evidence in the assignment chain or patent text indicates a bankruptcy proceeding leading to the sale of this patent. Orckit Communications Ltd. was acquired, not necessarily dissolved via bankruptcy.

7. Privateering — unclear

   • While the patent originated with an operating company (Orckit Communications Ltd.), there's no direct evidence in the provided text or assignment records to suggest that Orckit or its successors are actively directing or benefiting from the assertion by Quicker Connections LLC against competitors.

8. Defensive aggregator (anti-NPE) — not present

   • The chain terminates with Quicker Connections LLC, an entity actively engaged in litigation, not a known defensive aggregator.

Verdict

NPE — high confidence

This verdict is based on multiple strong signals. The transfer from Orckit Communications Ltd. to "Orckit IP, LLC" (Reel 038541/0984) clearly indicates the creation of an IP holding entity. This was followed by a cascading transfer through "Suca Ltd." to "Quicker Connections LLC" (Reel 070953/0085 and 071087/0641), with the latter being the asserting entity in ongoing litigation in the Texas Eastern District Court. The recurrence of specific correspondents, such as JOHN M VANOPHEM, BARNES & THORNBURG LLP, across these shell-entity transfers (Reel 070953/0085 and 071087/0641) further supports this finding. The Patent Security Agreement to IP Litfin US 2024 LLC (Reel 069230/0593) executed close to the litigation date also points towards a litigation-financing arrangement, a common NPE pattern.

For verification, refer to the USPTO Assignment Center search for US Patent 6822943: https://assignmentcenter.uspto.gov/.

References

US6822943B1 - Network access multiplexer with protocol address translation. Google Patents. Retrieved from https://patents.google.com/patent/US6822943/en (Fetched: 2026-07-29T06:09:23.500Z)
Orckit Communications Ltd. Company Profile: Acquisition & Investors. CB Insights. Retrieved from https://www.cbinsights.com/company/orckit-communications (Access Date: 2026-07-29)
Orckit Communications Ltd. Business Profile. Bloomberg. Retrieved from https://www.bloomberg.com/profile/company/ORCT:US (Access Date: 2026-07-29)
Orckit Communication Ltd. acquired Corrigent Systems Ltd. in March 2007. Mergr. Retrieved from https://mergr.com/orckit-communications-acquires-corrigent-systems (Access Date: 2026-07-29)
MRV Communications to Acquire Corrigent Systems. Lightwave. Retrieved from https://www.lightwaveonline.com/home/article/16694678/mrv-communications-to-acquire-corrigent-systems (Access Date: 2026-07-29)
Orckit Communications (ORCT): A Deep Dive into a Niche Player. Seeking Alpha. Retrieved from https://seekingalpha.com/article/10411-orckit-communications-orct-a-deep-dive-into-a-niche-player (Access Date: 2026-07-29)
USPTO Patent Assignment Search for US6822943. United States Patent and Trademark Office. Retrieved from https://assignmentcenter.uspto.gov/patent/index.html (Accessed: 2026-07-29)

The following prior art references are cited in US patent 6822943. The analysis identifies potential anticipation under 35 U.S.C. § 102 by comparing the cited patent's description (primarily its title, given the limitations in abstract retrieval) against the independent claims of US6822943.

Independent Claim 1 (Apparatus) of US6822943 key elements: A multi-shelf system (master and slave shelves in a topology), with slave shelves having unique internal network-layer addresses determined by topology. A management station uses a common external network-layer address by mapping internal network-layer addresses to respective transport-layer addresses (e.g., UDP ports) for configuration and maintenance.

Independent Claim 17 (Method) of US6822943 key elements: Similar to Claim 1, this method involves linking a master and slave shelves in a topology, assigning unique internal network-layer addresses based on topology, and conveying management instructions from a management station to the master shelf using a common external network-layer address by mapping internal network-layer addresses to transport-layer addresses.

Cited Patent References:

1. US6339594B1

• Full Citation: US6339594B1, "Wan-based gateway", At&T Corp., published 2002-01-15.
• Publication/Filing Date: Priority date: 1996-11-07; Publication date: 2002-01-15.
• Brief Description: This patent describes a Wide Area Network-based gateway.
• Potential Anticipation under 35 U.S.C. § 102: The title "Wan-based gateway" is too general to definitively anticipate the specific multi-shelf architecture, topology-based internal addressing, and the explicit mapping of internal network-layer addresses to transport-layer addresses for management messages over a common external address as claimed in US6822943. Without a detailed abstract, it's unlikely to anticipate the core innovations of Claims 1 and 17.

2. US5889470A

• Full Citation: US5889470A, "Digital subscriber line access device management information base", Paradyne Corporation, published 1999-03-30.
• Publication/Filing Date: Priority date: 1996-12-24; Publication date: 1999-03-30.
• Brief Description: This patent relates to a management information base (MIB) for digital subscriber line access devices.
• Potential Anticipation under 35 U.S.C. § 102: While related to DSL device management, the title does not suggest a multi-shelf system with hierarchical addressing using transport-layer ports to share a single external IP address based on topology. Therefore, it is unlikely to anticipate Claims 1 and 17 of US6822943.

3. US6058445A

• Full Citation: US6058445A, "Data management method for adding or exchanging components on a running computer", Micron Electronics, Inc., published 2000-05-02.
• Publication/Filing Date: Priority date: 1997-05-13; Publication date: 2000-05-02.
• Brief Description: This patent describes a data management method for dynamic component changes in a computer.
• Potential Anticipation under 35 U.S.C. § 102: This patent appears to deal with hot-swapping or dynamic component management at a system level, not specifically network address translation or management in a multi-shelf DSLAM system as claimed in US6822943. It is unlikely to anticipate Claims 1 and 17.

4. US6310862B1

• Full Citation: US6310862B1, "Real-time multimedia conferencing over an ATM network using an intelligent ATM cable modem and hybrid fiber-coax access", At&T Corp., published 2001-10-30.
• Publication/Filing Date: Priority date: 1997-06-24; Publication date: 2001-10-30.
• Brief Description: This patent focuses on real-time multimedia conferencing over an ATM network, involving ATM cable modems.
• Potential Anticipation under 35 U.S.C. § 102: While it mentions ATM networks (which is a component of US6822943's preferred embodiment), the core subject of real-time multimedia conferencing and cable modems does not align with the specific network address translation for multi-shelf management described in US6822943. Thus, it is unlikely to anticipate Claims 1 and 17.

5. US6085245A

• Full Citation: US6085245A, "System and method for the implicit support of IP subnetworks", Paradyne Corporation, published 2000-07-04.
• Publication/Filing Date: Priority date: 1997-07-24; Publication date: 2000-07-04.
• Brief Description: This patent describes a system and method for implicitly supporting IP subnetworks.
• Potential Anticipation under 35 U.S.C. § 102: The concept of "implicit support of IP subnetworks" might touch on address management, but it's not clear if it involves a multi-shelf architecture, topology-based addressing, and the use of transport-layer ports for management in the manner claimed by US6822943. More details would be needed, but based solely on the title, it is unlikely to fully anticipate Claims 1 and 17.

6. US6597689B1

• Full Citation: US6597689B1, "SVC signaling system and method", Nortel Networks Limited, published 2003-07-22.
• Publication/Filing Date: Priority date: 1998-12-30; Publication date: 2003-07-22.
• Brief Description: This patent relates to Switched Virtual Connection (SVC) signaling systems and methods.
• Potential Anticipation under 35 U.S.C. § 102: SVC signaling is a lower-layer connection management aspect of ATM, and while US6822943 uses ATM, this patent's focus on SVC signaling does not address the higher-level network address translation and management specific to multi-shelf systems as claimed. It is unlikely to anticipate Claims 1 and 17.

7. US6522688B1

• Full Citation: US6522688B1, "PCM codec and modem for 56K bi-directional transmission", Eric Morgan Dowling, published 2003-02-18.
• Publication/Filing Date: Priority date: 1999-01-14; Publication date: 2003-02-18.
• Brief Description: This patent describes a PCM codec and modem for 56K bi-directional transmission.
• Potential Anticipation under 35 U.S.C. § 102: This patent is directed to modem technology (PCM codec and 56K transmission), which is distinct from the network address translation and management for multi-shelf access systems in US6822943. It is unlikely to anticipate Claims 1 and 17.

8. US6636505B1

• Full Citation: US6636505B1, "Method for service provisioning a broadband modem", 3Com Corporation, published 2003-10-21.
• Publication/Filing Date: Priority date: 1999-05-28; Publication date: 2003-10-21.
• Brief Description: This patent discloses a method for provisioning services to a broadband modem.
• Potential Anticipation under 35 U.S.C. § 102: "Service provisioning a broadband modem" touches on management but typically at the individual modem level, not a multi-shelf DSLAM system with the specific address translation scheme for internal management as defined in US6822943. It is unlikely to anticipate Claims 1 and 17.

9. US6580727B1

• Full Citation: US6580727B1, "Element management system for a digital subscriber line access multiplexer", Texas Instruments Incorporated, published 2003-06-17.
• Publication/Filing Date: Priority date: 1999-08-20; Publication date: 2003-06-17.
• Brief Description: This patent describes an element management system (EMS) for a Digital Subscriber Line Access Multiplexer (DSLAM).
• Potential Anticipation under 35 U.S.C. § 102: This patent is highly relevant as it explicitly concerns management of a DSLAM. The core question is whether its "element management system" employs the specific address translation scheme of US6822943 (common external IP, internal IP mapped to transport-layer port based on topology for multiple shelves). While it addresses DSLAM management, the title alone doesn't confirm the unique addressing mechanism. This patent would require a deeper dive (beyond just the title) to fully assess its anticipatory potential. However, the presence of an "element management system for a digital subscriber line access multiplexer" suggests a high degree of relevance to the field of the invention.

10. US6404861B1

• Full Citation: US6404861B1, "DSL modem with management capability", E-Cell Technologies, published 2002-06-11.
• Publication/Filing Date: Priority date: 1999-10-25; Publication date: 2002-06-11.
• Brief Description: This patent concerns a DSL modem that includes management capabilities.
• Potential Anticipation under 35 U.S.C. § 102: Similar to US6636505B1, this patent focuses on managing an individual DSL modem. It is distinct from the multi-shelf system management and address translation claimed in US6822943. Thus, it is unlikely to anticipate Claims 1 and 17.

11. US6628649B1

• Full Citation: US6628649B1, "Apparatus and methods providing redundant routing in a switched network device", Cisco Technology, Inc., published 2003-09-30.
• Publication/Filing Date: Priority date: 1999-10-29; Publication date: 2003-09-30.
• Brief Description: This patent describes apparatus and methods for providing redundant routing in a switched network device.
• Potential Anticipation under 35 U.S.C. § 102: Redundant routing is a network reliability feature. While a DSLAM might employ such features, this patent does not appear to address the specific addressing scheme for management of multiple shelves using transport-layer port mapping as claimed in US6822943. It is unlikely to anticipate Claims 1 and 17.

12. US6680904B1

• Full Citation: US6680904B1, "Bi-directional chaining of network access ports", Orckit Communications Ltd., published 2004-01-20.
• Publication/Filing Date: Priority date: 1999-12-27; Publication date: 2004-01-20.
• Brief Description: This patent describes bi-directional chaining of network access ports. Notably, the US6822943 patent description explicitly references this co-pending application, stating: "Most preferably, slave shelves 26 are arranged in multiple daisy chains, as described in co-pending U.S. patent application Ser. No. 09/472,683, entitled “Bi-Directional Chaining of Network Access Ports,” which is assigned to the assignee of the present patent application, and whose disclosure is incorporated herein by reference." The provided citation, US6680904B1, has a priority date before US6822943's filing date. This indicates a close relationship between the two patents.
• Potential Anticipation under 35 U.S.C. § 102: This patent is highly relevant because it describes the daisy-chain topology for slave shelves that is a preferred embodiment of US6822943, and is even cited as related art. Specifically, US6822943, in its description of the topology, mentions: "In a preferred embodiment, the topology comprises a plurality of daisy chains, over which the slave switching units are coupled to communicate with the master switching unit, and the internal network-layer address of each of the slave shelves is determined uniquely by an identifying number of the chain in which the shelf is located and a position of the shelf in the chain." [cite: 6822943, Col. 6, lines 17-23]. This means US6680904B1 likely anticipates the "plurality of daisy chains" aspect of the system topology in Claim 1 and Claim 17 of US6822943. However, it is less likely to anticipate the entire unique addressing scheme (common external IP, internal IP mapped to transport layer port for management) unless its abstract or claims explicitly detail this specific address translation for multi-shelf management. It anticipates elements related to the physical arrangement and how position determines an identifier within that context.

13. US6512739B1

• Full Citation: US6512739B1, "Method and apparatus for down conversion within an X-DSL receiver", Ikanos Communications, Inc., published 2003-01-28.
• Publication/Filing Date: Priority date: 2000-01-07; Publication date: 2003-01-28.
• Brief Description: This patent describes a method and apparatus for down conversion in an xDSL receiver.
• Potential Anticipation under 35 U.S.C. § 102: This patent pertains to the physical layer signal processing (down conversion) in an xDSL receiver, which is fundamentally different from the network layer management and address translation of US6822943. It is unlikely to anticipate Claims 1 and 17.

14. US6434221B1

• Full Citation: US6434221B1, "Digital subscriber line access and network testing multiplexer", Sunrise Telecom, Inc., published 2002-08-13.
• Publication/Filing Date: Priority date: 2000-05-17; Publication date: 2002-08-13.
• Brief Description: This patent covers a digital subscriber line access and network testing multiplexer.
• Potential Anticipation under 35 U.S.C. § 102: While it mentions a DSL access multiplexer and network testing, its focus seems to be on testing functions rather than the specific network address translation for multi-shelf management of US6822943. It is unlikely to anticipate Claims 1 and 17.

15. US6469630B1

• Full Citation: US6469630B1, "System and method for determining the environmental configuration of telecommunications equipment", Cisco Technology, Inc., published 2002-10-22.
• Publication/Filing Date: Priority date: 2001-08-24; Publication date: 2002-10-22.
• Brief Description: This patent describes a system and method for determining the environmental configuration of telecommunications equipment.
• Potential Anticipation under 35 U.S.C. § 102: This patent relates to environmental configuration, which is a broader management concept. It is not specifically directed to network address translation for multi-shelf systems using transport-layer ports for management as claimed in US6822943. It is unlikely to anticipate Claims 1 and 17.

Most Relevant Prior Art:

Based on the titles and the explicit cross-reference in US6822943, US6680904B1 ("Bi-directional chaining of network access ports") is considered the most relevant prior art. While it does not explicitly detail the full address translation scheme, it describes the "daisy chain" topology for slave shelves that is central to the topology-based addressing in US6822943. The parent patent US6822943 itself states that the slave shelves are "preferably arranged in multiple daisy chains, as described in co-pending U.S. patent application Ser. No. 09/472,683, entitled 'Bi-Directional Chaining of Network Access Ports,' which is assigned to the assignee of the present patent application, and whose disclosure is incorporated herein by reference." [cite: 6822943, Col. 5, lines 26-32]. This co-pending application later issued as US6680904B1. Therefore, US6680904B1 likely anticipates the structural arrangement of the slave shelves and the concept of determining internal network-layer addresses based on their position within this topology, as mentioned in claim 15 and 16 of US6822943.

US6580727B1 ("Element management system for a digital subscriber line access multiplexer") is also highly relevant due to its focus on managing a DSLAM, which is the specific type of multi-shelf system described in US6822943. While its title does not explicitly disclose the unique addressing scheme of US6822943, its general scope in DSLAM management suggests it would be a critical piece of prior art for a more detailed anticipation analysis, particularly of the preamble and broad management aspects of Claims 1 and 17.

Obviousness Analysis under 35 U.S.C. § 103

A patent claim is unpatentable if "the differences between the claimed invention and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art" (35 U.S.C. § 103). This analysis considers the scope and content of the prior art, differences between the prior art and the claims, the level of ordinary skill in the art, and any secondary considerations of non-obviousness.

The present invention, US patent 6822943, addresses the efficient management of multi-shelf network access multiplexing systems, particularly DSLAMs, by conserving IP addresses through the use of transport-layer (UDP) ports for addressing individual shelves.

Level of Ordinary Skill in the Art:
A person having ordinary skill in the art (POSA) in the context of US6822943 would likely possess a bachelor's degree in electrical engineering, computer science, or a related field, coupled with several years of experience in designing, implementing, or managing telecommunications networks, particularly DSL systems, ATM networks, and IP-based management systems. Familiarity with network protocols like IP, UDP, SNMP, and IP over ATM would be expected.

Prior Art References:

The patent itself identifies several relevant prior art documents, specifically IETF Request for Comments (RFCs), which are authoritative documents from the Internet Engineering Task Force, a primary standards-setting body for the Internet. These include:

• IETF RFC 2631: "Diffie-Hellman Key Agreement Method" (June 1999): This RFC describes a key agreement algorithm. While primarily focused on security, the general concept of established IETF standards and protocols, as well as the need for efficient network resource utilization, would be understood by a POSA.
• IETF RFC 1901: "Introduction to Community-based SNMPv2" (January 1996): This RFC defines the Community-based Administrative Framework for SNMP version 2. It details the use of SNMP for network management, including protocol operations and transport mappings, with UDP being the preferred mapping.
• IETF RFC 2225: "Classical IP and ARP over ATM" (April 1998): This RFC describes how IP and ARP operate over ATM networks. It defines address resolution services in Logical IP Subnets (LIS) and the configuration requirements for ATM ARP tables.
• U.S. patent application Ser. No. 09/472,683: "Bi-Directional Chaining of Network Access Ports" (filed December 27, 1999, granted as US6680904B1 on January 20, 2004): This co-pending application, incorporated by reference in US6822943, describes the physical arrangement of slave shelves in daisy chains, which is a key aspect of the topology in the claimed invention.

Obviousness Combinations:

A POSA, at the time of the invention (November 8, 2000), would have been motivated to combine the teachings of these prior art references to arrive at the claimed invention.

Combination 1: RFC 1901 (SNMP/UDP Management) + RFC 2225 (IP over ATM) + US 09/472,683 (Multi-shelf Topology) + General Knowledge of IP Address Scarcity (e.g., as acknowledged by RFC 2631 introduction of NAT).

• Motivation: The primary motivation would be to efficiently manage a multi-shelf DSLAM system while conserving scarce IP addresses. RFC 1901 clearly establishes SNMP as a standard for network management and highlights UDP as a preferred transport mapping. RFC 2225 provides the foundation for running IP-based management over an ATM infrastructure, which is common in DSLAMs. U.S. patent application Ser. No. 09/472,683 describes a multi-shelf DSLAM architecture with daisy-chained slave shelves, making it a relevant structural component.
• Reasoning for Combination:
  • Shared External IP Address: Given the growing scarcity of public IP addresses, a POSA would be motivated to minimize the number of external IP addresses used for management. The concept of Network Address Translation (NAT) for conserving IP addresses was already known and proposed by the IETF (as cited in US6822943, referring to RFC 2631).
  • Mapping Internal IP to Transport-Layer Address (UDP Port): Since SNMP (RFC 1901) often uses UDP ports, a POSA would find it obvious to leverage different UDP ports to differentiate between individually addressable network elements (the shelves) that share a common external IP address. This effectively re-purposes the UDP port from merely a session-layer identifier to a pseudo-hardware address in the context of the external management network, allowing a single external IP address to multiplex management traffic to multiple internal shelves. RFC 1901's emphasis on UDP as a preferred mapping would reinforce this.
  • Automatic Topology-Based Addressing: The concept of automatically assigning internal addresses based on topology is a logical extension for managing complex multi-shelf systems like those described in U.S. patent application Ser. No. 09/472,683. If shelves are arranged in daisy chains, assigning addresses based on chain number and position within the chain is a straightforward and efficient method for automated configuration, reducing manual intervention and potential errors. This would be a natural design choice for simplifying management in a multi-shelf system. The patent US6822943 itself states that the internal IP addresses are assigned uniquely based on the topology of the slave shelves in relation to the master shelf, and the mapping is carried out automatically by the master shelf based on this topology.

Combination 2: RFC 1901 (Multiple Presentation-Layer Protocols with UDP) + General Networking Knowledge.

• Motivation: Management systems often need to support various presentation-layer protocols (e.g., SNMP, TFTP, Telnet) for different types of management functions. RFC 1901 provides an introduction to SNMP, which itself is a management protocol.
• Reasoning for Combination: It would be obvious to a POSA to extend the mapping scheme to include multiple session-layer ports (e.g., UDP ports) for each internal network-layer address, where each port corresponds to a different presentation-layer protocol. This is standard practice in networking, where different services (and thus different presentation-layer protocols) are assigned distinct ports to allow a single IP address to host multiple applications. Table I in US6822943 explicitly shows this, assigning different UDP ports (e.g., 10011 for SNMP, 10012 for TFTP, 10013 for Telnet) to the same internal IP address of the master shelf.

Conclusion:

The core claims of US6822943, particularly claims 1 and 17, which describe using a common external network-layer address (IP address) for multiple shelves by mapping internal network-layer addresses to respective transport-layer addresses (UDP ports), would have been obvious to a person having ordinary skill in the art. This is because the underlying technologies (DSLAMs, multi-shelf architectures, IP over ATM, SNMP management with UDP, and the concept of NAT for IP conservation) were well-established and documented in the prior art. The motivation to combine these elements would stem from the desire to efficiently manage complex multi-shelf systems while addressing the known issue of IP address scarcity. The automatic assignment of internal addresses based on topology is a logical design optimization for such systems.