OI Electric Co., Ltd. — 5 prefixes (MA-L)

A MAC address beginning with 00:10:C1, 50:9F:3B, 88:35:C1, D8:4A:87, or D8:F1:D8 belongs to OI Electric Co., Ltd. (大井電気, "Oi Electric"), a Japanese manufacturer of optical transmission, monitoring-and-control, and IoT gateway equipment — typically seen on telecom, power-utility, and railway infrastructure hardware rather than consumer devices.

IEEE's public OUI registry lists all five blocks under the identical organization name and registered address. That itself is a signal of an ongoing manufacturer rather than a one-off registrant: a shell company has no operational reason to hold five separate 24-bit MA-L allocations.

OI Electric is a real, publicly traded company (Tokyo Stock Exchange ticker 6822), headquartered at the exact registered OUI address in Kikuna, Kohoku-ku, Yokohama. Founded in 1949 and incorporated in January 1950, the company states it was the first in Japan to commercialize the pager. This is corroborated independently by the company's own site, Japanese Wikipedia, and multiple financial-data aggregators.

The company's stated product line — optical/media converters, transmission systems, monitoring and control units, and IoT/LPWA and LoRaWAN gateways for telecom, power-utility, and railway operators — plausibly explains the need for repeated MAC-address allocations across networked field and infrastructure equipment, though no single source ties a specific model number to a specific one of the five prefixes.

No registration date is recorded for any of the five blocks: IEEE does not publish OUI assignment dates, and any "date registered" shown by third-party MAC-lookup tools is a database artifact, not an IEEE fact. No CVEs or security advisories were found for OI Electric devices in this pass — an absence of findable evidence, not a clean-record claim.

Organization name

OI ELECTRIC CO.,LTD. [Confirmed] — the IEEE MA-L registry

Registry / block count

MA-L (24-bit OUI); 5 distinct blocks under the identical name+address [Confirmed] — the IEEE MA-L registry

Matching OUI assignments

00:10:C1, 50:9F:3B, 88:35:C1, D8:4A:87, D8:F1:D8 [Confirmed] — the IEEE MA-L registry (lines 18542, 26399, 33671, 35259, 30915)

Registered address

7-3-16 Kikuna, Kohoku-ku, Yokohama, Kanagawa-ken, JP 222-0011 [Confirmed] — the IEEE MA-L registry; https://www.ooi.co.jp/en/company/about

Company identity

Oi Electric Co., Ltd. (大井電気), publicly traded, Tokyo Stock Exchange ticker 6822, HQ at the registered OUI address [Confirmed] — https://www.ooi.co.jp/en/company/about, https://ja.wikipedia.org/wiki/%E5%A4%A7%E4%BA%95%E9%9B%BB%E6%B0%97

Founding

1949, incorporated January 1950; states it was the first Japanese firm to commercialize the pager [Confirmed] — https://www.ooi.co.jp/en/company/about

Company substance verdict

five independent OUI blocks plus an active public-company footprint (site, Wikipedia, financial aggregators) is verifiable substance beyond a bare IEEE registration — not a shell registrant [Confirmed] — cross-referenced registry + company + aggregator sources

Device types

optical/media transmission equipment, monitoring & control systems, IoT/LPWA & LoRaWAN gateways, security/surveillance & remote-sensing systems [Likely] — https://us.metoree.com/companies/2639/, https://www.ooi.co.jp/en/company/about

Registration date

Unknown / not applicable — IEEE publishes no assignment date for MA-L blocks; none of the 5 rows carry a date field [Confirmed] — the IEEE MA-L registry

Security context

Unknown — no CVEs or advisories found for OI Electric devices in this pass (absence of evidence, not confirmation of safety) [Unknown]

Employee count

minor unresolved discrepancy (407 per company site vs 948 per a financial aggregator); non-load-bearing [Unknown] — https://www.ooi.co.jp/en/company/about

Slug-to-prefix mapping

the bare queue slug does not map to a single prefix in the registry; this entry consolidates all 5 blocks under one vendor page, mirroring the multi-OUI vendor-apple pattern [Confirmed] — this site's own enrichment records, the IEEE MA-L registry