DCT
8:20-cv-00758
Intl License Exchange Of America LLC v. Moxa Inc
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Intl License Exchange of America LLC (Delaware)
- Defendant: Moxa Inc. (Taiwan) and Moxa Americas Inc. (California)
- Plaintiff’s Counsel: Devlin Law Firm
- Case Identification: 8:20-cv-00758, C.D. Cal., 04/17/2020
- Venue Allegations: Venue is alleged to be proper in the Central District of California because Defendant Moxa Americas Inc Inc. is a California corporation with a place of business in the district and has allegedly committed acts of infringement there. Venue over Moxa Inc. is based on its status as a foreign corporation.
- Core Dispute: Plaintiff alleges that Defendant’s networking equipment, including Ethernet switches and routers, infringes six U.S. patents related to the formatting of data frames for Virtual Local Area Networks (VLANs).
- Technical Context: The technology at issue is VLAN tagging, a foundational method for segmenting network traffic within modern Ethernet networks to improve performance and security, as standardized in IEEE 802.1Q.
- Key Procedural History: The asserted patents are part of a family originating from a single 1996 application. Five of the six patents-in-suit are reissued patents, which suggests their claims may have been reviewed and potentially amended by the U.S. Patent and Trademark Office after their initial issuance.
Case Timeline
| Date | Event |
|---|---|
| 1996-03-12 | Earliest Priority Date for all Patents-in-Suit |
| 1999-09-28 | U.S. Patent No. 5959990 Issued |
| 2009-11-24 | U.S. Patent No. RE40,999 Issued |
| 2014-02-25 | U.S. Patent No. RE44,775 Issued |
| 2014-08-05 | U.S. Patent No. RE45,065 Issued |
| 2014-08-19 | U.S. Patent No. RE45,081 Issued |
| 2014-08-26 | U.S. Patent No. RE45,095 Issued |
| 2020-04-17 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 5,959,990 - "VLAN Frame Format"
- Patent Identification: U.S. Patent No. US5959990A, "VLAN Frame Format", issued September 28, 1999 (’990 Patent).
The Invention Explained
- Problem Addressed: The patent describes the technical challenge of managing network traffic in complex local area networks (LANs). As networks grow, they are often segmented into logical groups called Virtual LANs (VLANs). However, when data frames from different VLANs travel over a shared communication link between network switches, the standard Ethernet frame format lacks a mechanism to preserve the frame's original VLAN association, creating ambiguity for the receiving switch (’990 Patent, col. 4:42-49).
- The Patented Solution: The invention proposes modifying the standard data frame to include a new "VLAN header." This header is inserted into the frame and contains a "virtual network identifier field" that explicitly tags the frame with its VLAN membership. A new "virtual type" (VTYPE) field is also added to signal the presence of this VLAN header, allowing VLAN-aware devices to correctly interpret the frame and route it to the appropriate virtual network (’990 Patent, Abstract; col. 8:14-30; Fig. 5B).
- Technical Importance: This method of explicitly tagging frames provides a standardized way to maintain VLAN context across an entire switched network, a concept the complaint alleges is a required part of the foundational IEEE 802.1Q networking standard (Compl. ¶15).
Key Claims at a Glance
- The complaint asserts independent claim 1 (Compl. ¶21).
- Claim 1 requires a method of transmitting a data frame that includes the steps of:
- transmitting a data frame having a type field whose contents indicate the frame comprises a virtual network identifier field; and
- transmitting the virtual network identifier field whose contents indicate the virtual network associated with the data frame.
U.S. Patent No. RE40,999 - "VLAN Frame Format"
- Patent Identification: U.S. Patent No. USRE40999E1, "VLAN Frame Format", issued November 24, 2009 (’999 Patent).
The Invention Explained
- Problem Addressed: The patent addresses the same problem as the ’990 Patent: the need for a reliable method to identify a data frame's VLAN association when it is transmitted over a shared medium connecting multiple network devices (RE40999 Patent, col. 4:51-60).
- The Patented Solution: This reissue patent claims the specific process of modifying a standard data frame to add a VLAN tag. The method involves receiving a frame with a "first type field" (the original EtherType), inserting a "second type field" to indicate the presence of a VLAN tag, and then inserting the "virtual network identifier field" between the new and original type fields before re-transmitting the frame (RE40,999 Patent, col. 11:23-48). This provides a more detailed description of the frame-tagging mechanism.
- Technical Importance: Like the ’990 Patent, this technology is alleged to be fundamental to the operation of the IEEE 802.1Q standard for managing modern Ethernet networks (Compl. ¶28).
Key Claims at a Glance
- The complaint asserts independent claims 1 and 7 (Compl. ¶34).
- Claim 1 requires a method comprising the steps of:
- receiving a data frame with a first type field;
- inserting a second type field before the first type field, with the value of the second type field indicating the frame includes a virtual network identifier field;
- inserting the virtual network identifier field between the second and first type fields;
- assigning a value to the virtual network identifier field corresponding to the virtual network; and
- transmitting the modified data frame.
- Claim 7 is similar to claim 1 but recites receiving a frame with a "length field" instead of a "type field," thereby addressing IEEE 802.3 frame formats in addition to Ethernet II formats.
U.S. Patent No. RE44,775 - "VLAN Frame Format"
- Patent Identification: RE44775, "VLAN Frame Format", issued February 25, 2014 (’775 Patent).
- Technology Synopsis: This patent claims methods for a network device receiving a VLAN-tagged data frame. The claimed method includes receiving the various fields of the tagged frame (MAC addresses, type field, identifier field) and using the value of the identifier field to determine the frame's VLAN association (Compl. ¶¶43, 50, 54).
- Asserted Claims: Independent claim 43 and dependent claims 44, 49, and 50 (Compl. ¶49).
- Accused Features: The accused products’ alleged 802.1Q-compliant functionality for receiving and processing VLAN-tagged frames (Compl. ¶49).
U.S. Patent No. RE45,081 - "VLAN Frame Format"
- Patent Identification: RE45081, "VLAN Frame Format", issued August 19, 2014 (’081 Patent).
- Technology Synopsis: This patent claims an end-to-end method of transmitting a data frame between two network devices. The method includes steps performed at a first device (receiving a standard frame and inserting a VLAN tag) and steps performed at a second device (receiving the tagged frame and processing the tag to determine the VLAN) (Compl. ¶¶62, 69).
- Asserted Claims: Independent claims 17, 21, and 25 (Compl. ¶68).
- Accused Features: The accused products’ alleged 802.1Q-compliant functionality for both tagging outgoing frames and processing incoming tagged frames (Compl. ¶68).
U.S. Patent No. RE45,065 - "VLAN Frame Format"
- Patent Identification: RE45065, "VLAN Frame Format", issued August 5, 2014 (’065 Patent).
- Technology Synopsis: This patent claims a network device (an apparatus claim) comprising ports and a processing unit. The processing unit is configured to perform the method of receiving a VLAN-tagged frame, reading its type field and virtual network header, and transmitting the frame toward the determined virtual network (Compl. ¶¶79, 82, 84).
- Asserted Claims: Independent claims 17 and 28 (Compl. ¶81).
- Accused Features: The physical hardware and configured processing units of the accused switches and routers that allegedly implement 802.1Q functionality (Compl. ¶81).
U.S. Patent No. RE45,095 - "VLAN Frame Format"
- Patent Identification: RE45095, "VLAN Frame Format", issued August 26, 2014 (’095 Patent).
- Technology Synopsis: This patent claims a method of transmitting a VLAN-tagged data frame where the virtual network identifier field can be in one of a "plurality of formats." The value of the virtual network type field indicates which format is being used (Compl. ¶¶90, 97).
- Asserted Claims: Independent claim 17 (Compl. ¶96).
- Accused Features: The accused products’ alleged 802.1Q-compliant functionality for transmitting VLAN-tagged frames (Compl. ¶96).
III. The Accused Instrumentality
Product Identification
- The accused instrumentalities are a range of Moxa-branded networking equipment, including Layer 2 and Layer 3 managed Ethernet switches, Smart Switches, Routers (including EN 50155 models), Rackmount Switches, and Wireless AP/Bridge/Client products (Compl. ¶21).
Functionality and Market Context
- The complaint alleges these products are "802.1Q-compliant," meaning they are designed to operate according to the IEEE 802.1Q standard for VLANs (Compl. ¶21). This functionality allows network administrators to create and manage virtual networks by tagging data frames with VLAN identifiers. The complaint references numerous product series on Moxa’s website, suggesting the allegations cover a significant portion of Moxa's industrial networking portfolio (Compl. ¶23, ¶36).
IV. Analysis of Infringement Allegations
’990 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a) transmitting a data frame having a type field whose contents indicate said data frame comprises a virtual network identifier field | The accused products transmit Ethernet frames where the Tag Protocol Identifier (TPID) field has a value (e.g., 0x8100) that signals the presence of an 802.1Q VLAN tag. | ¶22, ¶23 | col. 8:18-21 |
| b) transmitting said virtual network identifier field whose contents indicate said virtual network associated with said data frame | The accused products transmit the 802.1Q tag, which contains the VLAN Identifier (VID) that specifies which of the possible 4094 virtual networks the frame belongs to. | ¶22, ¶23 | col. 8:53-58 |
’999 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a) receiving the data frame from the communications medium, where the data frame includes a first type field and a data field | The accused devices receive a standard Ethernet II data frame containing an EtherType field. | ¶35, ¶36 | col. 10:28-31 |
| b) inserting a second type field at a location within the data frame preceding the first type field, a value of the second type field indicating the data frame include a virtual network identifier field | The accused devices insert the 802.1Q Tag Protocol Identifier (TPID) into the frame before the original EtherType field to signal that the frame is now VLAN-tagged. | ¶35, ¶36 | col. 11:26-34 |
| c) inserting the virtual network identifier field at a location between the second type field and the first type field | The accused devices insert the Tag Control Information (TCI), which contains the VLAN ID, after the new TPID and before the original EtherType field. | ¶35, ¶36 | col. 11:35-37 |
| d) assigning a first value to the virtual network identifier field, the first value corresponding to the virtual network | Based on network configuration (e.g., the port on which the frame was received), the device assigns the appropriate VLAN ID value to the tag. | ¶35, ¶36 | col. 11:38-41 |
| e) transmitting the data frame over the shared communications medium | The device transmits the newly tagged data frame onto the network. | ¶35, ¶36 | col. 11:45-48 |
- Identified Points of Contention:
- Scope Questions: The complaint’s core theory is that compliance with the IEEE 802.1Q standard constitutes infringement (Compl. ¶15, ¶21). A central question will be whether the specific claim language can be interpreted to cover all mandatory implementations of that standard. A defendant may argue that the term "type field" in the ’990 Patent is limited to the specific "VTYPE" embodiment disclosed in the specification and does not read on the standard's "Tag Protocol Identifier" (TPID).
- Technical Questions: For the more detailed method claims (e.g., in the ’999 Patent), a question may arise as to whether the accused products perform every recited step in the claimed order. The complaint asserts infringement based on the products' compliance with the 802.1Q standard rather than detailing the specific operational steps of the accused devices' firmware or hardware. The sufficiency of these allegations may be challenged.
No probative visual evidence provided in complaint.
V. Key Claim Terms for Construction
The Term: "type field whose contents indicate said data frame comprises a virtual network identifier field" (’990 Patent, Claim 1)
Context and Importance: This term is central to the infringement allegation against the ’990 Patent. Its construction will determine whether the claim reads on devices implementing the modern IEEE 802.1Q standard. Plaintiff's case depends on this term being construed to cover the standard's Tag Protocol Identifier (TPID), which uses the value 0x8100 to signal a tagged frame.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The claim uses the generic functional language "type field whose contents indicate," rather than reciting the specific term "VTYPE" used to describe the preferred embodiment in the specification (’990 Patent, col. 8:18-21). This may support an interpretation covering any field that performs the claimed signaling function.
- Evidence for a Narrower Interpretation: The specification describes the invention as replacing the original Ethernet type field ("ETYPE" 503) with a new "VTYPE" field (513) (’990 Patent, col. 8:18-21, Fig. 5B). A defendant could argue that the claim term should be limited to this specific structure, where one type field is replaced by another, as distinguished from the 802.1Q standard's method of inserting a new field while preserving the original.
The Term: "inserting ... at a location between the second type field and the first type field" (’999 Patent, Claim 1)
Context and Importance: The precise structural relationship between the original frame components and the newly inserted VLAN tag components is a key limitation of this method claim. Practitioners may focus on this term because the physical layout of a data frame is rigidly defined by standards, and any deviation between the claimed structure and the accused structure could be a basis for non-infringement.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The term "between" does not inherently require immediate adjacency. It could be argued that as long as the identifier field is located somewhere after the new type field and somewhere before the original type field, the limitation is met.
- Evidence for a Narrower Interpretation: The patent figures illustrate a specific, contiguous sequence: new "VTYPE" field, then a "VLAN HEADER" (containing the identifier), then the original "ETYPE/LENGTH" field (RE40,999 Patent, Fig. 5B). A defendant may argue that the claim requires this exact sequence and that the "virtual network identifier field" must be part of a larger "VLAN Header" construct as depicted.
VI. Other Allegations
The complaint does not contain specific counts or factual allegations for indirect or willful infringement.
VII. Analyst’s Conclusion: Key Questions for the Case
- A central issue will be one of standard-essentiality and scope: The Plaintiff's case appears to rest on the assertion that the asserted patent claims are essential to the IEEE 802.1Q standard and that compliance with the standard is therefore infringement. The case will likely turn on whether the court agrees with this technical mapping and construes the claims broadly enough to read on all 802.1Q-compliant products, or if Defendant can identify legally significant differences between the standard's requirements and the specific limitations of the claims.
- A key battleground will be claim construction and validity: Given the fundamental nature of the technology, the validity of the patents will likely be challenged. The construction of key terms like "type field" will be critical. The fact that five of the six asserted patents are reissues indicates they have already undergone post-grant scrutiny at the USPTO, and the history of those proceedings could provide significant evidence for both parties regarding the proper interpretation and validity of the claims.