Cisco Systems Inc v. Monarch Networking Solutions LLC

1. Case Identification

• Case #: IPR2020-01227
• Patent #: 9,019,965
• Filed: July 6, 2020
• Petitioner(s): Cisco Systems, Inc.
• Challenged Claims: 1-3, 6, 10-13, 17-20

2. Patent Overview

• Title: Data Packet Routing Device and Associated Method
• Brief Description: The ’965 patent discloses methods and devices for routing Internet Protocol version 4 (IPv4) data packets between two private IPv4 domains across a public Internet Protocol version 6 (IPv6) network. The core technique involves encapsulating the IPv4 packet within an IPv6 packet and constructing the IPv6 destination or source address by combining a known IPv6 prefix with the private IPv4 address of the destination or source terminal.

3. Grounds for Unpatentability

Ground 1: Obviousness over Ananda and RFC 1918 - Claims 1 and 3 are obvious over Ananda in view of RFC 1918.

• Prior Art Relied Upon: Ananda (Application # 2004/0107287) and RFC 1918 (Request for Comments: 1918).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Ananda teaches a method and apparatus for enabling communication between IPv4 hosts across an IPv6 backbone, solving the same problem as the ’965 patent. Ananda explicitly discloses encapsulating an IPv4 packet from a source terminal in a first subnet (the "first IPv4 domain") into an IPv6 packet for routing across an IPv6 backbone to a destination terminal in a second subnet (the "second IPv4 domain"). Critically, Ananda teaches constructing the IPv6 destination address by combining an IPv6 prefix (derived from the IPv6 backbone) with portions of the destination terminal's IPv4 address. This combination, Petitioner asserted, meets the key limitation of claims 1 and 3 concerning the construction of the IPv6 destination address.
  • Motivation to Combine: While Ananda discloses that its IPv4 hosts may be assigned private addresses, RFC 1918 provides the express rationale for doing so. RFC 1918 details the well-known benefits of using private, non-routable IP addresses within enterprise networks, such as conserving the limited global IPv4 address space and providing greater network design flexibility. A POSITA implementing Ananda’s network transition solution would combine it with the standard practice of using private addresses as taught by RFC 1918 to gain these established advantages.
  • Expectation of Success: A POSITA would have a high expectation of success because implementing private IPv4 domains within Ananda's framework was a straightforward application of a well-known, standardized networking practice (RFC 1918) to a disclosed system (Ananda) to achieve predictable benefits.

Ground 2: Obviousness over Ananda, RFC 1918, and Wetterwald - Claims 2, 6, 10-13, and 17-20 are obvious over Ananda, RFC 1918, and Wetterwald.

• Prior Art Relied Upon: Ananda (Application # 2004/0107287), RFC 1918 (Request for Comments: 1918), and Wetterwald (Patent 7,639,686).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground addresses claims directed to the operations of the receiving gateway and the construction of the IPv6 source address. Petitioner argued that Ananda discloses the receiving gateway's functions, including decapsulating the IPv6 packet to extract the original IPv4 packet and routing it within the second IPv4 domain. However, Ananda’s example assigns the encapsulating device's IP address as the IPv6 source address. Wetterwald was introduced to cure this. Wetterwald explicitly teaches constructing an IPv6 source address for an IPv4-in-IPv6 packet by combining a prescribed address prefix with the private IPv4 address of the original source terminal. This directly maps to the key limitation in claims 2 and 6. Dependent claims related to electronic circuits, logic chips, and data storage were argued to be obvious implementations using conventional hardware.
  • Motivation to Combine: A POSITA would combine Wetterwald’s source address construction technique with the Ananda/RFC 1918 system to improve network reliability, security, and administration. Using the true source terminal's address in the IPv6 source field, as taught by Wetterwald, allows for accurate traffic monitoring, troubleshooting, and implementation of security policies (e.g., blocking a malicious host). This is a predictable improvement over Ananda's method.
  • Expectation of Success: Success was expected because Wetterwald’s technique for constructing a source address is substantially the same as Ananda’s technique for constructing a destination address. Applying this known technique to the source address to gain predictable benefits in network management was a simple and logical design choice for a POSITA.

4. Key Claim Construction Positions

• "constructed by combining": Petitioner argued this term should be given its plain and ordinary meaning of "to unite, merge, or join," and should not be limited to the specification's exemplary embodiment of simple concatenation. This construction is central to ensuring that the methods of address derivation in the prior art, which may involve translation and prefixing, fall within the scope of the claims.
• "domain": Petitioner contended that "domain" should be construed as "network" and does not require "common control" or a "single administrative authority." The petition argued the claims themselves define the commonality (e.g., "IPv4 domain" means devices using the IPv4 protocol), and the prior art discloses such networks or subnets, regardless of their administrative structure.

5. Arguments Regarding Discretionary Denial

• §325(d) - Same or Substantially Same Art: Petitioner argued that denial under §325(d) would be inappropriate. Although Ananda was cited in an Information Disclosure Statement (IDS) during prosecution, the Examiner never applied it in any rejection or discussed it substantively. RFC 1918 and Wetterwald were never cited or considered at all. Therefore, Petitioner contended the core arguments and prior art combinations in the petition were not previously presented to and considered by the PTO.
• §314(a) - Fintiv Factors: Petitioner argued that the factors from Apple Inc. v. Fintiv, Inc. weigh against discretionary denial. The parallel district court case was in a very early stage with minimal investment by the parties and the court. Petitioner highlighted that the trial date was uncertain, as the court had scheduled eight other trials for the same day, making a delay likely. Petitioner asserted the strong merits of the petition and the clear overlap in issues meant that an IPR would be the most efficient and effective way to resolve the invalidity dispute.

6. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1-3, 6, 10-13, and 17-20 of the ’965 patent as unpatentable.