PTAB

IPR2019-00909

Cisco Systems Inc v. Bushnell Hawthorne LLC

Key Events

Petition

petition

Title: Method for Geo-Location Based DNS Redirection
Brief Description: The ’686 patent describes a method for selecting an optimal internet service based on a user’s geographical location. The system purports to achieve this by transparently modifying Domain Name System (DNS) messages to direct network traffic to the most efficient server.

Prior Art Relied Upon: the Cisco NAT Paper (a 1997 Cisco white paper) and Logan (Patent 6,578,066).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that the Cisco NAT Paper taught a method for transparently altering DNS messages by modifying the question or answer sections to facilitate routing in multi-homed enterprise networks. Logan taught a system that determines a user's geo-location from a DNS request and selects the geographically closest server to provide content. The combination of Cisco NAT Paper's DNS modification technique with Logan's geo-location based server selection allegedly met all limitations of independent claim 17.
- Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine the references as they address the same problems of improving network efficiency, reliability, and load balancing in large, geographically dispersed networks. Petitioner contended a POSITA would integrate Logan's geo-location optimization into the multi-homed network framework of the Cisco NAT Paper to improve routing performance by directing users to the closest available server.
- Expectation of Success: The combination involved predictable software modifications using known techniques, such as IP address tables, and would have yielded the expected benefits of enhanced routing efficiency.

Prior Art Relied Upon: Logan (Patent 6,578,066).
Core Argument for this Ground:
- Prior Art Mapping: This ground was presented as an alternative based on the Patent Owner's apparent litigation position construing the claim term "modifies" to include merely populating a blank section of a DNS message. Petitioner asserted that Logan disclosed a server switch that receives a DNS request, determines the user's geo-location, and then populates the answer section of the DNS response with an ordered list of IP addresses based on that location. Under the Patent Owner’s broad construction, this act of populating the answer section would meet the "modifying" limitation, rendering the claims anticipated by Logan alone.

Prior Art Relied Upon: Cisco NAT Paper (a 1997 Cisco white paper), Logan (Patent 6,578,066), and Alteon (a 1999 Alteon Websystems white paper).
Core Argument for this Ground:
- Prior Art Mapping: This ground addressed dependent claims 26 and 30, which add limitations requiring operation at the OSI model's second layer (Layer 2) and forwarding non-DNS packets, respectively. Petitioner argued the Cisco NAT Paper/Logan combination provided the core geo-location based DNS modification system. Alteon was added to teach the specific Layer 2 functionality, as it disclosed a "Web switch" that intercepts DNS packets using Layer 2 or Layer 3 switching and forwards packets not identified as DNS requests to their destination.
- Motivation to Combine: A POSITA would be motivated to combine these references to create a comprehensive and efficient traffic management solution. Petitioner noted that Logan is assigned to Alteon Websystems and uses its products as examples, making the technologies complementary. A POSITA would combine Alteon’s efficient Layer 2 packet handling with the geo-location based routing of the primary combination to build a more robust system.

"Modifies the Question Section, the Answer Section, or Both...": Petitioner proposed this phrase means "changes the information already present in the question section, the answer section, or both." This construction was central to its primary obviousness argument, distinguishing modification from initial creation. It was also used to frame the alternative anticipation argument, which relied on the Patent Owner's broader construction that allegedly included merely populating a blank section.
"Transparently Altering": Petitioner proposed this means "modifying in a way that is not known to users or other servers." This construction supported the argument that the prior art methods, which also operated without user knowledge, met this limitation.

OSI Layer of Operation: Petitioner contended that while DNS is technically an application-layer (Layer 5) protocol, it adopted for the sake of argument the "special use" of "at Layer 2" advanced by the patent applicant during prosecution and the Patent Owner in litigation. This special use appeared to treat any modification of a DNS message's question or answer section as occurring at Layer 2. This was a critical point for the analysis of claim 26, allowing Petitioner to argue that the Cisco NAT Paper and Alteon taught the claimed Layer 2 operation under the Patent Owner's own apparent interpretation.

Petitioner argued that discretionary denial under 35 U.S.C. §325(d) or 35 U.S.C. §314(a) was not warranted. The core reasons provided were that the primary prior art references and combinations, specifically the Cisco NAT Paper and Logan, were never presented to or considered by the USPTO during prosecution. Additionally, Petitioner asserted that the parallel district court litigation was in its early stages, and an IPR would be an efficient use of resources.

Petitioner requested the institution of an inter partes review and the cancellation of claims 17-30 of the ’686 patent as unpatentable.