DCT
1:16-cv-12624
Akamai Tech Inc v. Limelight Networks Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Akamai Technologies, Inc. (Delaware)
- Defendant: Limelight Networks, Inc. (Delaware)
- Plaintiff’s Counsel: Choate, Hall & Stewart LLP
- Case Identification: 1:16-cv-12624, D. Mass., 12/27/2016
- Venue Allegations: Plaintiff alleges venue is proper in the District of Massachusetts because Defendant sells its accused services to customers in the district, regularly conducts business there, and maintains a regular and established place of business in Burlington, Massachusetts.
- Core Dispute: Plaintiff alleges that Defendant’s Orchestrate Platform and associated Content Delivery Network (CDN) services infringe three patents related to CDN request handling, optimal route selection, and cloud-based firewall services.
- Technical Context: CDN technology is foundational to modern internet infrastructure, enabling the fast and reliable delivery of web content, streaming media, and applications by distributing it to servers closer to end-users.
- Key Procedural History: The complaint does not mention any prior litigation between the parties, Inter Partes Review (IPR) proceedings, or licensing negotiations.
Case Timeline
| Date | Event |
|---|---|
| 2000-04-14 | ’319 Patent Priority Date |
| 2001-03-01 | ’538 Patent Priority Date |
| 2009-12-12 | ’769 Patent Priority Date |
| 2012-06-05 | ’538 Patent Issue Date |
| 2013-06-04 | ’769 Patent Issue Date |
| 2013-07-09 | ’319 Patent Issue Date |
| 2016-09-07 | Limelight Announces Web Application Firewall (WAF) Service |
| 2016-12-27 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 8,484,319 - "Content Delivery Network (CDN) Content Server Request Handling Mechanism with Metadata Framework Support," issued July 9, 2013
The Invention Explained
- Problem Addressed: In a large, multi-tenant CDN, there is a need to apply different, customer-specific content handling rules (e.g., caching, security, access control) to requests processed by shared edge servers (Compl. ¶21). The patent addresses the challenge of managing these complex, per-customer metadata specifications efficiently across a distributed network (’319 Patent, col. 1:37-48).
- The Patented Solution: The invention describes a framework for managing how edge servers handle content requests. It employs a two-tiered data structure: first, a "Host Configuration Table" (HCT) maps an incoming request (e.g., based on its host header) to a specific customer; second, this mapping points to a separate, customer-specific "configuration file" which contains the detailed content handling instructions for that customer's objects (’319 Patent, col. 10:39-51; Fig. 5). This allows for flexible customization while maintaining a structured system for identifying and applying the correct rules.
- Technical Importance: This architecture provides a scalable method for offering customized, high-value CDN services to many different customers on a shared infrastructure, separating the initial request identification from the application of complex, feature-specific rules (Compl. ¶21).
Key Claims at a Glance
- The complaint asserts independent claim 1, as well as claims 2 and 4-8 (Compl. ¶26).
- Independent Claim 1 requires, in summary:
- A data store storing a host configuration table (HCT) that identifies content provider domains and points to an associated configuration file.
- The configuration file contains at least one content handling instruction.
- Receiving a request for a content object, the request having a host header.
- Determining if the host header name value matches a domain entry in the HCT.
- If it matches, retrieving the configuration file.
- Applying the content handling instruction from the configuration file.
- Serving the content object in response to the request.
- The complaint does not explicitly reserve the right to assert other dependent claims.
U.S. Patent No. 8,194,538 - "Optimal Route Selection in a Content Delivery Network," issued June 5, 2012
The Invention Explained
- Problem Addressed: The public internet is an imperfect network, and the most direct path between a CDN edge server and a customer's origin server is not always the fastest or most reliable due to congestion, router misconfigurations, or peering disputes (’538 Patent, col. 1:10-2:13).
- The Patented Solution: The invention proposes a method to bypass public internet problems by using the CDN's own private or semi-private network. When an edge server needs to fetch content from an origin server, instead of taking the default direct internet route, it can identify and use an "alternate path" that "tunnels" the request through another, intermediate CDN server or region (’538 Patent, Abstract; col. 2:51-59). The system can use performance tests, or "races," to dynamically determine whether the direct path or an alternate path is currently optimal for that specific data transfer (’538 Patent, col. 7:1-12).
- Technical Importance: This technique improves the performance and reliability of fetching dynamic or non-cacheable content, a critical function for CDNs that support modern, interactive web applications (’538 Patent, col. 2:30-34).
Key Claims at a Glance
- The complaint asserts independent claim 1, as well as claims 2-3 and 5 (Compl. ¶38).
- Independent Claim 1 requires, in summary:
- For a given server node and content provider origin server, identifying at least one alternate path for communications.
- The alternate path must include at least one other CDN edge server that is external to the given server node.
- Upon receipt of a request for an object that is not available at a particular edge server, issuing a new request for the object from that server over the alternate path.
- The object must have an associated cacheability setting indicating it should not be cached at that particular edge server.
- Receiving the object over the alternate path and serving it in response to the request.
- The complaint does not explicitly reserve the right to assert other dependent claims.
U.S. Patent No. 8,458,769 - "Cloud Based Firewall System and Service," issued June 4, 2013
- Patent Identification: U.S. Patent No. 8,458,769, “Cloud Based Firewall System and Service,” issued June 4, 2013 (Compl. ¶9).
- Technology Synopsis: The patent addresses website security by describing a distributed firewall service implemented across a CDN’s edge servers (’769 Patent, Abstract). This architecture allows for network traffic to be inspected for threats at the network edge, preventing malicious requests from reaching a customer's origin server. The system is designed to be a multi-tenant service, allowing different customers to independently define and deploy distinct firewall settings for their respective content (’769 Patent, col. 3:11-36).
- Asserted Claims: Independent claims 1 and 17 (Compl. ¶46).
- Accused Features: The complaint accuses Limelight’s Web Application Firewall (WAF) service, which is integrated with its CDN and is described as a "cloud-based security service that detects and stops application attacks in real time" based on customer-configurable rules (Compl. ¶¶43-44).
III. The Accused Instrumentality
Product Identification
The Limelight Orchestrate Platform and its associated CDN services, including the Limelight Web Application Firewall (WAF) service (Compl. ¶¶ 12, 43).
Functionality and Market Context
The complaint describes the accused instrumentality as a "cloud-based suite of software built on top of a world-class content delivery network" that delivers various forms of digital content (Compl. ¶12). The platform operates on a physical network of over 80 "points-of-presence (PoPs)" globally, using caching proxy software on its edge servers (Compl. ¶13). For dynamic content, it allegedly uses a "connection mesh" to accelerate delivery between its POPs (Compl. ¶32). The platform also provides security through its WAF service, which filters traffic based on customer-configured rules (Compl. ¶43). Customers manage these services through a network-accessible portal named "Limelight Control" (Compl. ¶14). The complaint alleges that Limelight offers these CDN services in direct competition with Akamai (Compl. ¶12).
IV. Analysis of Infringement Allegations
No probative visual evidence provided in complaint.
’319 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a data store storing a host configuration table (HCT) that identifies one or more content provider domains or subdomains... wherein at least one entry in the HCT... points to a configuration file associated with the content provider domain or subdomain... | The Limelight CDN edge server includes a data store with a "configuration table" where an entry for a customer domain (aliased to a Limelight hostname) points to an associated "configuration file." | ¶21 | col. 21:26-34 |
| wherein the configuration file has at least one content handling instruction associated therewith | The customer's configuration file includes at least one content handling instruction, such as an instruction to "cache" content for a given time. | ¶21 | col. 21:35-37 |
| computer program instructions executed by the hardware processor for: receiving a request for a content object, the request being received from a client... the request for the content object having a host header associated therewith, the host header including a name value... | Limelight edge servers receive requests for customer content from end-user clients. The request includes a "header" with the customer's original domain. | ¶22 | col. 21:38-44 |
| determining whether the name value in the host header matches any content provider domain or subdomain entry in the HCT... | The edge server examines the header to determine if the customer domain is found in the configuration table. | ¶22 | col. 21:45-47 |
| if the name value in the host header matches any content provider domain or subdomain entry in the HCT, retrieving the configuration file... | If a match is found, the customer's configuration file is retrieved. | ¶22 | col. 22:42-44 |
| applying the content handling instruction in the configuration file; and after the content handling instruction is applied, serving the content object in response to the request. | The content handling instruction from the retrieved file is applied, and the edge server then serves the requested content. | ¶22, 23 | col. 22:45-50 |
- Identified Points of Contention:
- Scope Questions: A central question may be whether Limelight’s alleged "configuration table" (Compl. ¶21) is structurally and functionally equivalent to the claimed "Host Configuration Table." The complaint asserts that the configuration file is "distinct from the Host Configuration Table" (Compl. ¶25), raising the question of whether Limelight's system actually employs the two-tiered, distinct data structures required by the claim.
- Technical Questions: The infringement theory relies on a customer domain being "aliased (e.g., via a canonical name or "CNAME") to a Limelight hostname" (Compl. ¶21). The analysis may turn on evidence of how this aliasing and subsequent request processing maps to the claim's requirement that the edge server matches the original customer domain in the host header to an entry in the HCT.
’538 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| for each given server node and a content provider origin server, identifying at least one alternate path to be used for edge server-to-content provider origin server communications... | For each server node, Limelight's CDN identifies "at least one alternate path to be used for edge server-to-content provider origin server communications via the mesh." | ¶34 | col. 15:64-16:1 |
| ...the at least one alternate path including at least one other content delivery network edge server that is external to the given server node; | The alternate path allegedly "includes at least one other CDN edge server in another Limelight POP that is external to the local POP at which the initial request is received." | ¶34 | col. 16:2-6 |
| upon receipt at a particular edge server... of a request for an object that is not available for delivery from the particular edge server, issuing a new request for the object from the particular edge server over the at least one alternate path... | Upon receiving a request for an unavailable object, a "new request for the object is issued from the particular edge server over the at least one alternate path." | ¶34 | col. 16:7-13 |
| ...wherein the object has an associated cacheability setting, wherein the cacheability setting indicates that the object should not be cached in the particular edge server; | For dynamic content, the object has an "associated cacheability setting that indicates that the object should not be cached in the particular edge server." | ¶34 | col. 16:13-17 |
| receiving the object over the at least one alternate path; and serving the object in response to the request. | The object is received over the alternate path and is then served in response to the request. | ¶34 | col. 16:18-21 |
- Identified Points of Contention:
- Technical Questions: A key evidentiary question is whether Limelight's "connection mesh" (Compl. ¶32) for accelerating dynamic content operates as claimed. The complaint alleges, "upon information and belief," that a new request is issued over an alternate path containing another external edge server (Compl. ¶34). The case may require technical evidence to establish whether this specific sequence of operations actually occurs, or if the "connection mesh" uses a different, non-infringing acceleration technique.
- Scope Questions: The analysis may examine whether serving "dynamic content" (Compl. ¶31) is equivalent to the claim limitation of an object having a "cacheability setting" that indicates it "should not be cached." The parties may dispute whether all dynamic content necessarily has such a setting.
V. Key Claim Terms for Construction
For the ’319 Patent
- The Term: "Host Configuration Table" (HCT)
- Context and Importance: This term is foundational to the infringement theory for the ’319 Patent, which requires this table to be "distinct from the Host Configuration Table" (Compl. ¶25). The interpretation of HCT will determine whether Limelight's alleged architecture, which uses a "configuration table" (Compl. ¶21), meets this claim element. Practitioners may focus on this term because the distinction between the HCT and the "configuration file" is a core structural requirement of the asserted claim.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes the HCT's function as helping to "identify the request format during parsing, apply capability throttling to the request, and nominate a Customer Configuration ID" (’319 Patent, col. 10:40-44). This functional description could support an interpretation covering any lookup table that performs these mapping and identification roles, regardless of its specific implementation.
- Evidence for a Narrower Interpretation: An embodiment in the patent describes the HCT as a specific XML file with
<hct>and<config>elements that map<hostHeader>and<inARLToken>values to a customer ID (’319 Patent, col. 13:20-53). This could support a narrower construction limited to a structure that explicitly resembles this disclosed embodiment.
For the ’538 Patent
- The Term: "alternate path"
- Context and Importance: This term defines the core novelty of the ’538 patent. The infringement analysis hinges on whether Limelight's "connection mesh" (Compl. ¶32) constitutes an "alternate path" as claimed. Its construction will be critical to resolving the dispute over how Limelight accelerates dynamic content.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent's background section broadly frames the invention as a way to "optimize the edge server-origin server communication path" and "route data between content delivery network (CDN) regions" (’538 Patent, col. 2:36-44). This could support a broad reading of "alternate path" to mean any non-default route between CDN nodes used to retrieve content from an origin server.
- Evidence for a Narrower Interpretation: The claim itself requires the path to include "at least one other content delivery network edge server that is external to the given server node" (’538 Patent, col. 16:3-6). Furthermore, preferred embodiments describe the path being determined by "races" among different routes (’538 Patent, col. 7:1-12). This may support a narrower construction requiring the path to be chosen via a performance test and to explicitly traverse an external edge server, not just an intermediate routing point.
VI. Other Allegations
- Indirect Infringement: The complaint does not include specific counts for indirect or contributory infringement.
- Willful Infringement: The complaint does not contain an explicit allegation of willful infringement or facts to support pre-suit knowledge of the patents-in-suit. The prayer for relief includes a request for a declaration that the case is "exceptional" pursuant to 35 U.S.C. § 285, which can be based on litigation misconduct or substantive weakness of a party's case, in addition to willfulness (Compl. p. 15, ¶C).
VII. Analyst’s Conclusion: Key Questions for the Case
The resolution of this dispute may turn on the answers to several key questions:
- An Architectural Question: Can Akamai demonstrate that Limelight’s system for applying customer-specific rules employs the specific, two-tiered structure of a "Host Configuration Table" that is distinct from a "configuration file," as required by the '319 patent, or will evidence show a unitary or otherwise different architecture?
- A Technical and Evidentiary Question: What is the precise operational mechanism of Limelight’s "connection mesh"? Does it function by issuing a "new request" from a local POP over an "alternate path" that includes an external POP, as claimed in the '538 patent, or does it use a different method of inter-POP communication to accelerate content delivery?
- A Question of Scope and Customization: For the '769 patent, a central issue will be whether Limelight’s WAF service allows for the creation of distinct, independent firewall configurations for a first and second customer, as required by claim 1, and whether Akamai can produce evidence of such distinct configurations being deployed in the accused system.