OUI / MA-L
What Is an OUI?
OUI stands for Organizationally Unique Identifier. It is a 24-bit identifier assigned to an organization by the IEEE Registration Authority and has long been used in identity systems for Ethernet and other network devices.
Today, the large assignment traditionally referred to as an OUI is presented as MAC Address Block Large (MA-L). An MA-L assignment includes an OUI and the right to generate extended identifiers such as EUI-48 and EUI-64 from that OUI.
| Element | Role | How We Use It |
|---|---|---|
| OUI | A 24-bit foundation for identifying an organization | 00:16:AA is assigned to our company |
| EUI-48 | A 48-bit device identifier widely used as a MAC address | Uniquely manages products, individual units, and monitored assets |
| MA-L | A large identifier assignment that includes an OUI | A manufacturer foundation for generating and managing identifiers internally |
The IEEE Registration Authority explains that an MA-L assignment includes an OUI and the right to generate identifiers such as EUI-48 and EUI-64. For details, see the IEEE SA overview of MA-L.
OUR IDENTIFIER
Our OUI 00:16:AA
IEEE OUI
The IEEE public registration record identifies this assignment as belonging to Kei Communication Technology Inc.
For us, an OUI is the foundation for assigning consistent identifiers to the network interfaces of our products. We manage it as a long-term technical asset that associates devices, monitored assets, configurations, installation locations, and maintenance records.
By maintaining the same identity system from product shipment through remote monitoring, fault analysis, repair, and replacement, we can track which device is located where and in what condition over the long term.
The essential task is to continue assigning identifiers based on our own OUI, preventing duplication, maintaining records, and supporting maintenance as the manufacturer throughout the entire device lifecycle.
LIFECYCLE TRACEABILITY
Connecting Identity to the Entire Product Lifecycle
A MAC address enables a device to connect to a network, but operationally it can also serve as a primary key that links the device's history. Using our OUI as the starting point, we manage information consistently from manufacturing through maintenance.
Assignment
Assign a non-duplicating identifier to each product and individual unit
Shipment
Associate model numbers, serial numbers, and MAC addresses
Installation
Link the device to the user, site, and monitored asset
Monitoring and Maintenance
Record status, configuration changes, faults, and repair history
Replacement and Disposal
Preserve migration records and identifier history for successor equipment
IDENTIFY / MONITOR / CONTROL
An OUI Alone Does Not Protect Equipment
An OUI indicates the organization to which an identifier has been assigned. Understanding equipment status, anomalies, communication failures, and power failures also requires management protocols, MIBs, a monitoring platform, and a maintenance structure.
Identify devices
Give operational meaning to status data
Detect anomalies and restore operation
We operate our own OUI, proprietary SNMP protocol stack, MIBs, and user monitoring platform as one integrated system. This allows us not only to display MAC addresses, but also to continuously understand the status of identified equipment.
View our SNMP monitoring technology →OPERATIONAL AUTONOMY
Technical Autonomy from Device Identity Through Maintenance
Starting with device identity based on our own OUI, we manage monitoring, control, power, and maintenance records within a single operational framework.
Technical autonomy means understanding equipment configuration and status, isolating causes when anomalies occur, determining how to restore operation, and maintaining continuity.
The ability to continuously control identity, monitoring, control functions, power, and maintenance supports stable operation of critical infrastructure and contributes to economic security from a technical perspective.
Understand External Dependencies
- Who manufactured and supplied the equipment
- Which management protocols and cloud services the system depends on
- Whether logs and configurations remain accessible during a failure
- Whether alternatives are available if maintenance ends or a supplier exits the business
- Whether communication and power failures can be distinguished
Maintain Direct Operational Control
- Manage equipment with our own identity system
- Understand status through our own monitoring platform
- Continue fault diagnosis and maintenance domestically
- Monitor power and communications as one system
- Preserve essential functions during abnormal conditions
Technical Positioning
Starting with device identity based on our own OUI, we maintain monitoring, control, power, and maintenance within one operational framework, allowing us to understand equipment configuration and status directly and make the decisions required for recovery.
This technical autonomy supports stable operation of critical infrastructure, traceability, and explainability, and contributes to economic security from a technical perspective.
Japan's Cabinet Office framework for critical infrastructure reviews the introduction of specified critical equipment and the outsourcing of maintenance and related services in advance for risks that such arrangements could be used for external interference, with the aim of ensuring the stable provision of essential infrastructure services. The Information-technology Promotion Agency, Japan (IPA), also emphasizes that systems handling important information should enable users to understand their equipment configuration, supply chain, and operating structure and maintain control even under abnormal conditions.
WHAT OUI DOES NOT MEAN
What an OUI Does and Does Not Tell You
| What an OUI Can Confirm | What an OUI Alone Cannot Confirm |
|---|---|
| The organization to which the identifier is assigned | Product quality, safety, or security certification |
| A foundation for generating globally unique identifiers | Country of manufacture, component origin, or the full supply chain |
| One element of the manufacturer's identity-management capability | The current owner, installation location, or operating condition |
Virtualization, locally administered addresses, and privacy-oriented randomization can prevent the first 24 bits of a MAC address from reliably identifying the actual device manufacturer. An OUI is therefore an important asset-management clue, but it should be used together with asset registers, serial numbers, certificates, and monitoring data.
CONCLUSION
Long-Term Operational Responsibility Begins with Device Identity
Selling network equipment is different from identifying, monitoring, and maintaining that equipment over periods of 10 or 20 years. We maintain OUI 00:16:AA as our identity foundation and connect it to SNMP monitoring, power systems, and maintenance.
It records the network technology at the foundation of our company and remains a current technical asset for autonomously operating AI, communications, healthcare, municipal, disaster-prevention, and industrial infrastructure.
References
- IEEE SA: MAC Address Block Large (MA-L)
- IEEE SA: Registration Authority
- IEEE Registration Authority: Public Registration Record
- Cabinet Office of Japan: Framework for Ensuring the Stable Provision of Essential Infrastructure Services
- IPA: Requirements Guide for Systems Handling Important Information
This page contains technical information independently prepared and published by Kei Communication Technology Inc. It is not an official page operated or endorsed by IEEE or the IEEE Standards Association. Explanations of IEEE 802, OUI, EUI-48, EUI-64, and related identifiers are based on publicly available information from IEEE and the IEEE Registration Authority.