Cisco Systems Inc v. 802 Systems Inc

1. Case Identification

• Case #: IPR2021-00618
• Patent #: 8,458,784
• Filed: March 18, 2021
• Petitioner(s): Cisco Systems, Inc.
• Patent Owner(s): 802 Systems Inc.
• Challenged Claims: 1-9 and 11-17

2. Patent Overview

• Title: Methods and Systems for Firewall/Data Protection
• Brief Description: The ’784 patent discloses systems for filtering data packets in real time between an external network (e.g., the Internet) and an internal network. The system evaluates packets against filtering rules as they are being transmitted without buffering, and if a packet is deemed invalid or a determination cannot be made in time, it is "junked" by corrupting its data.

3. Grounds for Unpatentability

Ground 1: Claims 1-3 and 16-17 are obvious over Carter and Maria.

• Prior Art Relied Upon: Carter (Patent 5,386,470) and Maria (Patent 6,092,110).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Carter taught a low-latency multiport repeater that performs real-time packet filtering. As a packet is received and retransmitted, Carter’s device inspects header data (e.g., source/destination addresses) against stored access rules. If a packet is unauthorized, the repeater corrupts the remainder of the frame by overwriting it with meaningless data, thus selectively altering it. Maria taught the common network topology of placing a packet filter between an external network (Internet) and an internal network. Maria also disclosed a "restrictive mode" where packets are blocked by default unless they affirmatively match an allow rule, which maps to the ’784 patent’s limitation of invalidating a packet if a validity determination isn't made by the time the packet’s end is received.
  • Motivation to Combine: A POSITA would combine Carter’s efficient, low-latency filtering repeater with the common network environment taught by Maria (i.e., between an internal and external network) to provide a known security function. Further, a POSITA would incorporate Maria's default-deny "restrictive mode" into Carter’s system to resolve the timing challenge inherent in a non-buffering repeater. This would ensure security by defaulting to invalidating a packet when a complex rule evaluation cannot be completed before the packet must be fully retransmitted.
  • Expectation of Success: A POSITA would have a high expectation of success, as the combination involved applying a known filtering technique (Maria's restrictive mode) to a known filtering device (Carter's repeater) to achieve the predictable result of secure, real-time packet filtering in a standard network architecture.

Ground 2: Claims 4-9 and 11-12 are obvious over Carter, Maria, and Salim.

• Prior Art Relied Upon: Carter (Patent 5,386,470), Maria (Patent 6,092,110), and Salim (Patent 6,628,653).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground built upon the combination of Carter and Maria by adding the teachings of Salim to address claims requiring both stateful and non-stateful filtering. Petitioner asserted Carter taught non-stateful filtering (using static rules like source/destination addresses) and rudimentary stateful filtering (using a frame counter). Salim provided more advanced and explicit details for stateful filtering, such as IP traffic conditioning based on negotiated bandwidth, using a decision table to maintain state across multiple packets in a session.
  • Motivation to Combine: A POSITA, having combined Carter and Maria, would look to improve the system's filtering capabilities. Salim's disclosure of stateful inspection for firewall and traffic conditioning purposes provided a clear roadmap. A POSITA would be motivated to incorporate Salim’s stateful techniques into the Carter/Maria system to provide more robust security and network management, such as preventing bandwidth abuse, which was a known problem.
  • Expectation of Success: The combination would predictably result in a filter with both stateful and non-stateful capabilities. Implementing Salim's well-understood stateful filtering methods in Carter's device was a matter of applying known design principles.

Ground 3: Claims 13-15 are obvious over Carter, Maria, Salim, and Loschke.

• Prior Art Relied Upon: Carter (Patent 5,386,470), Maria (Patent 6,092,110), Salim (Patent 6,628,653), and Loschke (Patent 5,956,336).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground added Loschke to the previous combination to address claims reciting a "result aggregator logic" and a "completion signal." Loschke taught a high-speed comparator circuit using a Content Addressable Memory (CAM) for efficiently looking up header information. Loschke’s circuit included logic gates (e.g., an AND gate) to aggregate results from multiple different comparisons and generated an error flag bit to signal when a search was completed without a match.
  • Motivation to Combine: A POSITA implementing the Carter/Maria/Salim system would need to efficiently process multiple, complex filtering rules (both stateful and non-stateful) at line speed, as required by Carter's non-buffering repeater. Loschke’s high-speed CAM and comparator circuit provided a known solution to improve the speed and efficiency of database lookups. A POSITA would combine Loschke's teachings to implement Carter’s comparators and database, allowing the system to aggregate results and determine if all checks were complete.
  • Expectation of Success: Using a CAM-based comparator as taught by Loschke was a well-known technique for high-performance filtering applications. A POSITA would expect this implementation to predictably achieve the necessary speed and efficiency for the combined system to function as intended.

4. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §325(d) was inappropriate because the asserted prior art combinations were not previously presented to or considered by the USPTO during prosecution.
• Petitioner further argued that discretionary denial under Fintiv was inappropriate. It contended the parallel district court case was in its early stages with minimal investment from the parties and the court. Petitioner asserted that the scheduled trial date was nearly a year away and highly uncertain due to judicial backlogs, weighing against denial. Finally, Petitioner stipulated that if the IPR were instituted, it would not pursue the same invalidity grounds in the district court, thus avoiding duplicative efforts.

5. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1-9 and 11-17 of the ’784 patent as unpatentable.