PTAB

IPR2014-01179

Cisco Systems Inc v. Constellation Technologies LLC

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1. Case Identification

2. Patent Overview

  • Title: Automatic Protection Switching in Packet Networks
  • Brief Description: The ’048 patent describes a method and system for automatic protection switching in a packet network to re-route data packets upon a network link failure. The technology utilizes a pre-defined, closed-loop "protection path" or "p-cycle" to provide an alternate route around the failed link.

3. Grounds for Unpatentability

Ground 1: Obviousness over Grover '880, Grover1998, and RFC 2003 - Claims 1, 11, 12, 20-22, 25, 26, 29, 30, and 34 are obvious over the core combination.

  • Prior Art Relied Upon: Grover (Patent 6,914,880, "Grover '880"), Applicant's Admitted Prior Art (AAPA), Grover1998 (an IEEE conference paper), and RFC 2003 (an IETF standards document).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the primary reference, Grover '880, taught the foundational concept of using preconfigured cyclical routes ("p-cycles") to restore network failures by providing a detour for packets. While Grover '880 focused on node failures, it expressly stated its methods were also applicable to link failures. Grover1998, authored by the same inventor, was cited to explicitly detail the use of p-cycles for protecting against link failures, thus teaching the claimed "protection path" for a "protected link." The combination of Grover '880 and Grover1998 disclosed detecting a failure and rerouting packets along the p-cycle. Finally, RFC 2003 was asserted to teach a standard, well-known method of IP-in-IP encapsulation, which Petitioner mapped to the claims’ requirements for "encapsulating the packets within tunnel packets."
    • Motivation to Combine: Petitioner contended a person of ordinary skill in the art (POSITA), guided by Grover '880’s suggestion to protect link failures, would have looked to related works by the same inventor, such as Grover1998, for specific implementation details. Furthermore, a POSITA would combine this p-cycle protection scheme with the standardized and simpler IP-in-IP tunneling method of RFC 2003 to implement the packet rerouting, as it would obviate the need for the special packet handling described in Grover ’880 and improve interoperability.
    • Expectation of Success: A POSITA would have a high expectation of success in applying the standard tunneling protocol from RFC 2003 to the p-cycle network of Grover, as this involves using a well-documented technology for its intended purpose of routing packets along an alternate path.

Ground 2: Obviousness over Grover '880, Grover1998, RFC 2003, and RFC 1700 - Claims 2-4, 23, 24, 27, and 28 are obvious over the core combination plus RFC 1700.

  • Prior Art Relied Upon: Grover '880, AAPA, Grover1998, RFC 2003, and RFC 1700 (an IETF standards document).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground built upon the core combination from Ground 1 to address dependent claims requiring the packet header to specify the packet’s nature (e.g., "tunnel packet or a non-tunnel packet"). Petitioner argued that RFC 2003 taught using a specific protocol field value of "4" in the outer IP header to signify IP-in-IP encapsulation. RFC 1700, a foundational standards document, was introduced to show that it defined the meaning of these protocol field values, explicitly assigning the value "4" to IP-in-IP tunneling. This combination, therefore, taught a header that specifies the packet type.
    • Motivation to Combine: Petitioner asserted that a POSITA implementing the tunneling taught in RFC 2003 would be motivated to consult RFC 1700, the standard for "Assigned Numbers," to correctly interpret and use the protocol field values. This was presented as a routine step in applying a known standard.
    • Expectation of Success: The combination was argued to be a straightforward application of established internet standards, leading to a high expectation of success.

Ground 3: Obviousness over Grover '880, Grover1998, RFC 2003, and RFC 1812 - Claims 13-16 and 19 are obvious over the core combination plus RFC 1812.

  • Prior Art Relied Upon: Grover '880, AAPA, Grover1998, RFC 2003, and RFC 1812 (an IETF standards document).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground addressed claims detailing the steps a router takes when processing received packets, such as determining a destination node and deciding whether to forward a packet or process it locally. Petitioner argued that RFC 1812, which specifies the requirements for IP Version 4 routers, explicitly taught these standard packet handling procedures. The argument was that the routers in Grover '880, when performing normal routing functions, would inherently operate according to these well-established router requirements.
    • Motivation to Combine: A POSITA would be motivated to incorporate the standard router functionalities of RFC 1812 into the Grover '880 system to ensure the routers were compliant with prevailing industry standards for routing packets, thereby ensuring interoperability and predictable network behavior.
    • Expectation of Success: Integrating standard router processing logic into a routing system was presented as a predictable and routine design choice with a clear expectation of success.
  • Additional Grounds: Petitioner asserted additional obviousness challenges based on combinations including RFC 2473 (for nested tunneling), Fee (Patent 6,285,475) (for physical layer failure detection), Chan (Patent 6,301,254) (for logical layer failure detection), Swallow (Patent 6,751,190) (for MPLS label switching), and Teraslinna (Patent 5,623,492) (for source/destination labels).

4. Key Claim Construction Positions

  • "protection path" (all claims): Petitioner argued this term should be construed as "a p-cycle consisting of a closed loop of nodes and links that can provide an alternative path in case of a failure in a network." This construction was critical for mapping the "p-cycle" teachings of the Grover references onto the claims.
  • "encapsulated / encapsulating" (all claims): Petitioner proposed this means "the inclusion of a first datagram/packet in the body of a second datagram/packet by adding a header for the second datagram/packet." This construction aligned the claims with the standard IP-in-IP tunneling technique described in RFC 2003.
  • "tunnel packet" (all claims): Consistent with the above, Petitioner argued this term means "a packet/datagram, encapsulating another packet/datagram, to be forwarded using a tunnel." This linked the claim term directly to the technology disclosed in RFC 2003.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-36 of the ’048 patent as unpatentable.