Akamai Tech Inc v. Limelight Networks Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Akamai Technologies, Inc. (Delaware) and Massachusetts Institute of Technology (Massachusetts)
  • Defendant: Limelight Networks, Inc. (Delaware)
  • Plaintiff’s Counsel: Choate, Hall & Stewart
• Case Identification: 1:06-cv-11109, D. Mass., 06/23/2006
• Venue Allegations: Venue is alleged to be proper based on Defendant’s business dealings, revenue derived from Massachusetts, and infringing activities causing injury within the district.
• Core Dispute: Plaintiffs allege that Defendant’s content delivery network services infringe patents related to methods for distributing internet content from a network of distributed servers.
• Technical Context: The technology at issue involves Content Delivery Networks (CDNs), which are critical infrastructure for accelerating the delivery of web content (such as images and videos) to end-users by serving it from servers geographically closer to the user.
• Key Procedural History: The patents-in-suit were assigned to Plaintiff Massachusetts Institute of Technology (MIT), and Plaintiff Akamai Technologies, Inc. is the exclusive licensee. The '413 Patent is a continuation of the application that resulted in the '703 Patent, indicating a close technical and legal relationship between the two patents.

Case Timeline

Date	Event
1998-07-14	Priority Date for '703 and '413 Patents
2000-08-22	U.S. Patent No. 6,108,703 Issues
2003-04-22	U.S. Patent No. 6,553,413 Issues
2006-06-23	Complaint Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 6,108,703, "Global Hosting System" (issued Aug. 22, 2000)

• The Invention Explained:
  • Problem Addressed: The patent describes the problems of traditional website "mirroring," where entire copies of a website are placed on different servers. This approach is described as economically inefficient, difficult to scale, and can lead to content providers losing control over content delivery, resulting in inaccurate traffic data and the serving of outdated information to users (ʼ703 Patent, col. 1:35-54; col. 2:4-16).
  • The Patented Solution: The invention proposes a "global hosting framework" (a CDN) where a website's main document (e.g., the base HTML page) is served from the original content provider's server, but some or all of the "embedded objects" within that page (e.g., images, scripts) are served from a distributed network of "ghost servers." This is accomplished by modifying the Uniform Resource Locators (URLs) for the embedded objects to direct a user's browser to retrieve them from the distributed network, preferably from a server that is geographically near the user (ʼ703 Patent, Abstract; col. 3:4-16).
  • Technical Importance: This architecture allows for faster, more scalable content delivery by decentralizing the hosting of data-heavy objects, while allowing the content provider to maintain primary control over its content via the base page (ʼ703 Patent, col. 2:31-35).
• Key Claims at a Glance:
  • The complaint does not identify the specific claims being asserted. Independent claim 1 is representative of the invention's core method.
  • Claim 1 (Method) Elements:
    • A routine for modifying an embedded object URL to include a hostname "prepended" to the original domain name.
    • Providing a set of "content servers" distinct from the original "content provider server."
    • Using a hierarchical Domain Name Service (DNS) with first-level and second-level name servers.
    • In response to a request, the base web page with the modified URL is served from the content provider server, while the embedded object itself is served from one of the distributed content servers, as identified by the hierarchical DNS. (ʼ703 Patent, col. 17:15-37).
  • The complaint does not explicitly reserve the right to assert dependent claims.

U.S. Patent No. 6,553,413, "Content Delivery Network Using Edge-of-Network Servers for Providing Content Delivery to a Set of Participating Content Providers" (issued Apr. 22, 2003)

• The Invention Explained:
  • Problem Addressed: The '413 Patent, a continuation of the '703 Patent's application, addresses the same fundamental problems of inefficient and difficult-to-manage web content distribution (ʼ413 Patent, col. 1:44 - col. 2:10).
  • The Patented Solution: This patent further details the mechanism for directing user requests. It describes a method where a content provider "tags" its content by associating it with a URL containing a special "alphanumeric string." This string is resolvable by the CDN's proprietary DNS system. The CDN's DNS uses this string, along with information like the user's location and network traffic, to select an optimal edge server from its network to deliver the content (ʼ413 Patent, Abstract; col. 10:1-22).
  • Technical Importance: The invention refines the CDN concept by describing a more dynamic, intelligent DNS-based routing system capable of making server-selection decisions based on real-time network conditions (ʼ413 Patent, col. 10:23-30).
• Key Claims at a Glance:
  • The complaint does not identify the specific claims being asserted. Independent claim 1 is representative of the invention's core method.
  • Claim 1 (Method) Elements:
    • A content provider identifies a "given object" for delivery by the CDN.
    • The object is associated with a URL containing an "alphanumeric string" that is resolvable by the CDN's DNS.
    • A first DNS query on a "first portion" of the string selects a CDN name server.
    • A second DNS query at that name server, using a "second portion" of the string, identifies a specific server from the CDN's set of content servers.
    • That identified server receives the request and serves the object. (ʼ413 Patent, col. 17:31 - col. 18:5).
  • The complaint does not explicitly reserve the right to assert dependent claims.

III. The Accused Instrumentality

• Product Identification: The complaint does not identify any specific accused products, methods, or services offered by Defendant Limelight Networks, Inc. (Compl. ¶¶ 13, 18).
• Functionality and Market Context: The complaint does not provide sufficient detail for analysis of the functionality or market position of any accused instrumentality.

IV. Analysis of Infringement Allegations

The complaint makes only conclusory allegations of infringement and does not provide a claim chart, a narrative infringement theory, or specific facts explaining how the Defendant’s services allegedly meet the limitations of any asserted claim (Compl. ¶¶ 13, 18). No probative visual evidence provided in complaint.

• Identified Points of Contention:
  • Given the lack of specific allegations, any infringement analysis will depend entirely on facts developed during discovery. However, based on the technology, disputes may center on several key technical and legal questions.
  • For the ’703 Patent: A central question may be whether the Defendant’s system performs all steps of the claimed method. For example, the claims require a "routine for modifying" URLs on a page served by a content provider, while other steps are performed by the CDN's servers. This raises the question of whether a single entity, the Defendant, can be held liable for direct infringement if its customers perform some of the required steps.
  • For the ’413 Patent: A key technical question will likely be whether the Defendant’s system uses an "alphanumeric string" with distinct "first portion" and "second portion" components that are resolved in the specific hierarchical DNS query process required by the claims. The analysis will require a detailed examination of how the Defendant’s URL structure and DNS resolution logic actually operate. The issue of divided performance of the method steps between the Defendant and its customers, as described for the ’703 Patent, is also pertinent here.

V. Key Claim Terms for Construction

The complaint provides no basis for identifying disputed terms. However, in litigation involving this technology, the following terms from the representative independent claims would likely be central to the dispute.

Term from ’703 Patent, Claim 1: "modifying at least one embedded object URL ... to include a hostname prepended"

• Context and Importance: This term defines the essential action that redirects content requests from the content provider to the CDN. The scope of "modifying" and "prepending" will be critical to determining infringement. Practitioners may focus on this term because the specific technical method used to redirect browser requests is a fundamental design choice in any CDN.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The patent’s "Brief Summary of the Invention" broadly describes a system that "moves content close to the user," which could support an argument that any technical means of achieving this redirection is covered (ʼ703 Patent, col. 2:40-42).
  • Evidence for a Narrower Interpretation: The detailed description and Figure 4 illustrate a specific process where a "virtual server hostname is prepended" to the URL, and a "fingerprint" value is also added. This detailed embodiment could be used to argue for a narrower construction limited to literal string manipulation of the URL (ʼ703 Patent, col. 6:41-56; Fig. 4).

Term from ’413 Patent, Claim 1: "an alphanumeric string that is resolvable"

• Context and Importance: The structure and function of this "alphanumeric string" are at the heart of the '413 patent's claimed invention. The dispute will likely turn on whether the Defendant's system uses a URL component that functions in the manner described.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The term "alphanumeric string" itself is broad and could be argued to cover any combination of letters and numbers in the URL that the CDN's DNS uses as an input for routing.
  • Evidence for a Narrower Interpretation: The specification inherited from the parent '703 patent describes a highly structured hostname that includes a "serial number field," a "lower level DNS field," and a "top level DNS field," suggesting the "alphanumeric string" is not arbitrary but is a structured token intended for a specific, multi-part DNS resolution process ('703 Patent, col. 9:11-18, incorporated into the '413 patent).

VI. Other Allegations

• Indirect Infringement: The complaint alleges that the Defendant "actively has induced... others to infringe" both the '703 and '413 patents. The complaint does not, however, plead any specific facts to support these allegations, such as the existence of user manuals or instructions that would direct Defendant's customers to perform the claimed steps (Compl. ¶¶ 14, 19).
• Willful Infringement: The complaint alleges that the Defendant's infringement "has been, and continues to be, willful and deliberate." No specific factual basis for this allegation, such as pre-suit notice or knowledge of the patents, is provided in the complaint (Compl. ¶¶ 15, 20).

VII. Analyst’s Conclusion: Key Questions for the Case

• A central legal issue for the case will be one of divided infringement. As the asserted patents claim methods whose steps appear to be performed by different parties (the content provider and the CDN), a threshold question will be whether Plaintiffs can prove that Defendant Limelight directs or controls its customers' actions to such an extent that all steps can be attributed to a single actor for infringement purposes.
• A key technical and evidentiary question will be one of operational correspondence. Plaintiffs will bear the burden of proving that the specific architecture of Defendant's CDN services—particularly its URL rewriting and DNS-based server selection mechanisms—maps directly onto the technical steps as recited in the patent claims.
• An immediate procedural question is one of pleading sufficiency. The complaint's lack of specific factual allegations regarding the accused products and the mechanism of infringement may give rise to early challenges regarding whether it provides the Defendant with adequate notice of the claims against it.