Cisco Systems Inc v. Monarch Networking Solutions LLC

1. Case Identification

• Case #: IPR2020-01679
• Patent #: 8,451,845
• Filed: October 1, 2020
• Petitioner(s): Cisco Systems, Inc.
• Patent Owner(s): Monarch Networking Solutions LLC
• Challenged Claims: 1, 5-8

2. Patent Overview

• Title: Method and Device for Receiving a Data Packet in an IPv6 Domain
• Brief Description: The ’845 patent relates to telecommunications networks that facilitate the transition from IPv4 to IPv6 addressing. The technology involves a method and device (e.g., a home gateway) for receiving and processing data packets, particularly for constructing and regularizing IPv6 addresses to enable communication between IPv4 and IPv6 domains.

3. Grounds for Unpatentability

Ground 1: Claims 1 and 5-8 are obvious over Ananda, Wetterwald, and RFC4380.

• Prior Art Relied Upon: Ananda (Application # 2004/0107287), Wetterwald (Patent 7,639,686), and RFC4380 ("Teredo: Tunneling IPv6 over UDP through Network Address Translations").
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Ananda taught the foundational system for enabling communication between IPv4 and IPv6 networks. Ananda disclosed a method where a communications protocol interface (CPI), functioning as a gateway, receives an IPv4 data packet, encapsulates it within an IPv6 packet for transmission across an IPv6 backbone, and then decapsulates it at the destination. Ananda further taught constructing the IPv6 destination address by combining a known IPv6 prefix with the destination IPv4 address. However, Petitioner contended Ananda did not explicitly teach including a destination port number in the constructed address or using a Network Address Translation (NAT) table for public-to-private address translation. Wetterwald was cited for its teachings on using NAT and Port Address Translation (PAT) to manage address spaces, specifically translating between public and private IPv4 addresses. RFC4380 was cited for its disclosure of the Teredo protocol, which explicitly included a destination port number within a constructed IPv6 address to facilitate routing and enhance security.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine these references to solve known problems and improve upon Ananda's system. First, Ananda itself addressed the shortage of IPv4 addresses and the use of private addressing, creating a motivation to incorporate Wetterwald's well-known NAT/PAT solution for managing public-to-private address translation. This would allow hosts in Ananda’s system to use private IPv4 addresses without exposing them on public networks. Second, a POSITA would be motivated to add a destination port number to Ananda's constructed IPv6 address, as taught by Wetterwald and RFC4380, to enhance security. RFC4380 explicitly used the port number to detect potentially fraudulent ("spoofed") traffic, a known problem in the art. This modification would provide a useful verification mechanism in Ananda's system.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success in this combination. Ananda's method for constructing an IPv6 address involved prefixing 32 zero bits to a 32-bit IPv4 address to create a 64-bit segment. A POSITA would recognize that the 16-bit port number taught by RFC4380 could easily be substituted for some of the unused zero bits, making the modification straightforward. Similarly, incorporating Wetterwald's standard NAT/PAT functionality into Ananda's gateway to handle address translation was a predictable implementation of a known solution to a known problem.

4. Key Claim Construction Positions

• "domain" (Claims 1, 5, 7, 8): Petitioner argued that no special construction is necessary, but if one is adopted, "domain" should be construed as "network." Petitioner asserted that the ’845 patent uses the terms synonymously and that the claims themselves provide the necessary context (e.g., "IPv4 domain" communicates using the IPv4 protocol).
• "means for" Limitations (Claim 8): Petitioner contended that several terms in claim 8 are means-plus-function limitations under §112, ¶ 6 and proposed the following constructions:
  • "means for identifying an IPv6 destination address...":
    • Function: Identifying an IPv6 destination address constructed by concatenating an IPv6 prefix, an IPv4 destination address, and a destination port number.
    • Structure: A receiver device (e.g., device 25 of home gateway 20) having a processor (251) and memory (255), and equivalents.
  • "means for regularizing...":
    • Function: (1) Regularizing the IPv6 source address by replacing it, or (2) regularizing the IPv6 destination address by replacing it, and modifying the data packet using the regularized address.
    • Structure: A device (e.g., device 25) having a processor (251) and a memory (255) that stores a NAT table for address translation, and equivalents.
  • "means for routing...":
    • Function: Routing the IPv6 data packet to its destination.
    • Structure: Telecommunications means (254) of the receiver device (25), and equivalents.

5. Arguments Regarding Discretionary Denial

• §325(d) - Same or Substantially the Same Art: Petitioner argued against discretionary denial because the primary references, Ananda and RFC4380, were not considered or cited during the prosecution of the ’845 patent. While a related publication to Wetterwald was cited by the Examiner, Petitioner asserted that the specific, relevant teachings of Wetterwald relied upon in the petition were not applied or substantively discussed during prosecution, and their relevance was therefore overlooked.
• §314(a) - Fintiv Factors: Petitioner argued that the Fintiv factors weighed against discretionary denial. Key arguments included:
  • The parallel district court litigation was in its early stages with minimal investment by the court and parties.
  • While a trial was scheduled, its date was highly uncertain as the court had scheduled eight other cases for the same day, making it likely the trial would be moved to a date after the FWD deadline.
  • Petitioner stipulated that if the IPR is instituted, it would cease asserting the same combination of references in the district court litigation, thus reducing overlap.
  • The merits of the petition were presented as being particularly strong, which is a factor that weighs against denial.

6. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1 and 5-8 of Patent 8,451,845 as unpatentable.