PTAB

IPR2024-00126

Oxylabs UAB v. Bright Data Ltd

Key Events

Petition

petition Intelligence

Title: System and Method for Internet Content Caching and Distribution
Brief Description: The ’826 patent describes a method where a "first server" receives a content identifier (e.g., a URL) from a client device, selects an IP address from a stored list based on a criterion, and uses that selected IP address to forward the content identifier onward to retrieve web content.

Prior Art Relied Upon: Kocherlakota (Patent 6,785,705).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Kocherlakota discloses all limitations of the challenged claims. Kocherlakota describes a system of chained proxy servers for routing web requests. Petitioner asserted that Kocherlakota’s first proxy server (proxy 17) functions as the claimed "first server." This proxy receives a URL from a client computer, stores a list of IP addresses for downstream proxies (e.g., proxies 19 and 21), and selects one of these IP addresses based on pre-configured routing rules (the claimed "criterion"). For example, based on matching a portion of the received URL, proxy 17 can "skip" or "jump to" specific downstream proxies, thereby selecting the IP address of the next proxy in the chain to forward the URL. The proxy then receives the requested content back from the web server via the proxy chain and sends it to the client.
- Dependent Claims: Petitioner further mapped dependent claims, arguing for example that criteria based on geographic location (claim 12) are disclosed by Kocherlakota’s reference to a "French language web proxy" and the use of the "*.fr" top-level domain as a matching criterion.

Prior Art Relied Upon: Kocherlakota (Patent 6,785,705) and RFC 1122 (Internet Engineering Task Force, Requirements for Internet Hosts – Communication Layers, October 1989).
Core Argument for this Ground:
- Prior Art Mapping: This ground built upon Ground 1, adding RFC 1122 to render obvious claims 6-9, which relate to using "keep alive" messages. RFC 1122 discloses a standard TCP "keep-alive" mechanism used to periodically probe a connection to confirm it is still active. Petitioner argued that the combination teaches sending a keep-alive message from the first server (Kocherlakota's proxy 17) to a second client device (Kocherlakota's downstream proxies 19 or 21), waiting for a response, and managing the list of available IP addresses based on whether a response is received.
- Motivation to Combine: A POSITA would combine these references to improve the reliability of Kocherlakota's proxy chain. Using the well-known TCP keep-alive functionality from RFC 1122 would allow the primary proxy to detect when a downstream proxy has crashed or become unresponsive, preventing the system from sending requests to a dead connection and consuming resources unnecessarily.
- Expectation of Success: The combination involved applying a standard network protocol (TCP keep-alive) to a known network architecture (a proxy chain) to achieve the predictable result of improved connection stability.

Prior Art Relied Upon: Cohen (Patent 6,389,462).
Core Argument for this Ground:
- Prior Art Mapping: As an alternative to Kocherlakota, Petitioner argued that Cohen renders the claims obvious. Cohen discloses a system where a "proxy redirector" transparently intercepts client web requests and forwards them to one of several available proxy caches. Petitioner mapped Cohen's proxy redirector to the claimed "first server." This redirector receives a URL, stores a list of IP addresses for the available proxy caches, and selects a proxy cache based on a criterion, such as a "least-loaded or round-robin" metric or IP header information. The redirector then forwards the request using the selected proxy's IP address.
- Dependent Claims: Petitioner argued that the "least-loaded" selection metric taught by Cohen is inherently based on response time (claim 12), as determining server load involves measuring its responsiveness.

Prior Art Relied Upon: Cohen (Patent 6,389,462) and RFC 1122.
Core Argument for this Ground:
- Prior Art Mapping: Similar to Ground 2, this ground added RFC 1122 to the primary reference (Cohen) to render claims 6-9 obvious. The combination teaches Cohen's proxy redirector using the TCP keep-alive mechanism from RFC 1122 to monitor the status of the proxy caches it manages.
- Motivation to Combine: A POSITA would be motivated to use RFC 1122's keep-alive feature to ensure that Cohen's proxy redirector only selects from proxy caches that are actually available and responsive. This would prevent routing requests to crashed or unavailable caches, directly improving the system's overall performance and reliability, a key goal of Cohen's invention.
- Expectation of Success: A POSITA would have reasonably expected success in implementing this combination, as it involved applying a standard network maintenance technique to a server management system for the predictable benefit of enhanced availability monitoring.

"Client Device" and "First Server": Petitioner argued that these terms should be construed based on the role a device plays in a particular transaction, not its physical hardware. Citing claim construction orders from related litigation, Petitioner asserted a "client device" is a "communication device that is operating in the role of a client," and a "first server" is "a device that is operating in the role of a server." This construction is critical because the proxies in the prior art (e.g., Kocherlakota's proxy 17) act as both a server (to the initial client) and a client (to the next proxy in the chain).
"Server operating system": Petitioner contended this term should be construed as a general-purpose operating system capable of operating in the role of a server, such as Linux or UNIX, which the prior art proxy systems would have used.

Petitioner argued that discretionary denial would be inappropriate because the key prior art references—Kocherlakota, Cohen, and RFC 1122—were cited in an Information Disclosure Statement (IDS) during prosecution but were never substantively analyzed or addressed by the Examiner. Petitioner asserted that the Examiner erred by allowing the claims and that this lack of prior examination weighs against discretionary denial.

Petitioner requests institution of an inter partes review and cancellation of claims 1-10, 12, 15-19, and 21-25 of the ’826 patent as unpatentable.