Amphenol — 4 OUI assignments (MA-L ×3, MA-S ×1) across US, DE, CN, IN

A MAC address starting with 78:A7:14, 00:0A:0D, or B4:DD:E0, or falling in the 70:B3:D5:A9:A sub-block, belongs to Amphenol Corporation or one of its subsidiaries — not a single consumer device class, but connector, cable, antenna, or networked-sensor hardware. Amphenol (NYSE: APH) is a publicly traded manufacturer founded in 1932, headquartered in Wallingford, Connecticut, reporting roughly $23.1 billion in 2025 revenue across three business segments.

IEEE registries list four separate Amphenol-family assignments. Three are MA-L (24-bit) blocks: 78:A7:14, registered to "Amphenol" at Endicott, NY, US; 00:0A:0D, registered to "Amphenol" at Berlin, DE; and B4:DD:E0, registered to Shanghai Amphenol Airwave Communication Electronics Co., Ltd. in Shanghai, CN. The fourth is an MA-S (36-bit) sub-block, 70:B3:D5:A9:A, registered to Amphenol Advanced Sensors via Amphenol Interconnect India Private Ltd, Hyderabad, IN.

That MA-S block sits inside 70:B3:D5, an IEEE-administered base sub-allocated in 36-bit slices to thousands of unrelated registrants. Only the specific 70:B3:D5:A9:A slice belongs to Amphenol — the bare 70:B3:D5 prefix must never be read as an Amphenol identifier, in prose or in any structured field.

The Berlin registration traces to FCI (Framatome Connectors International), which Amphenol acquired in January 2016 for $1.275 billion; a third-party lookup still shows the pre-acquisition legal-entity name for that prefix. Amphenol Advanced Sensors, the MA-S registrant, sells networked instruments — Kaye LabWatch environmental-monitoring consoles and Telaire CO2/humidity/temperature transmitters — with Ethernet, BACnet/IP, or Modbus TCP connectivity, though no source ties a specific sighted MAC to a named model.

No CVE is recorded in the NVD tying a vulnerability to Amphenol network hardware or firmware, as of an August 2026 search. Separately, Amphenol Corporation (the parent company, not any OUI-bearing device) appeared on a ransomware group's leak site around July 2023 — a corporate-level event, unrelated to device security. IEEE's public registries publish no assignment date for any of the four prefixes; a third-party aggregator's displayed dates are database artifacts, not IEEE facts.

Company

Amphenol Corporation (NYSE: APH), Wallingford, CT, US — connector, cable, antenna, and sensor manufacturer

Also seen on

Amphenol Advanced Sensors' Kaye LabWatch and Telaire environmental-monitoring instruments, which carry Ethernet/BACnet/Modbus TCP connectivity (amphenol-sensors.com/en/telaire/co2)

MA-L prefixes

78:A7:14 (Endicott, NY, US), 00:0A:0D (Berlin, DE), B4:DD:E0 (Shanghai Amphenol Airwave, CN)

MA-S sub-block

70:B3:D5:A9:A (Amphenol Advanced Sensors, Hyderabad, IN) — a slice of the shared 70:B3:D5 base, not the whole base

Not to be confused with

the bare 70:B3:D5 prefix, an IEEE-administered base shared across thousands of unrelated registrants

IEEE assignment

4 prefixes → Amphenol corporate family (3 MA-L + 1 MA-S) [Confirmed] — the IEEE MA-L registry B4DDE0, 78A714, 000A0D; the IEEE MA-S registry 70B3D5A9A

Registry / block size

MA-L (24-bit) ×3 + MA-S (36-bit) ×1 [Confirmed] — the IEEE MA-L registry; the IEEE MA-S registry

HQ / country

Wallingford, CT, US (corporate HQ); registry addresses also carry Endicott NY US, Berlin DE, Shanghai CN, and Hyderabad IN [Confirmed] — amphenol.com/about; the IEEE MA-L registry

Company status

active [Confirmed] — amphenol.com/about; stockanalysis.com/stocks/aph

Device types

connectors, cables, antennas; Amphenol Advanced Sensors line includes networked Kaye LabWatch / Telaire instruments [Likely] — instrumetrics.com AAS-BR-177A-LabWatch PDF; amphenol-sensors.com/en/telaire/co2

Notable products

Kaye Validator AVS, Kaye LabWatch, Telaire CO2/humidity/temperature transmitters

Verified sample prefixes

78:A7:14, 00:0A:0D, B4:DD:E0 (MA-L); 70:B3:D5:A9:A (MA-S, sub-block of shared 70:B3:D5 base) [Confirmed] — the IEEE MA-L registry; the IEEE MA-S registry

Shared-base caveat

70:B3:D5 is an IEEE-administered base sub-allocated to thousands of unrelated registrants; only 70:B3:D5:A9:A belongs to Amphenol [Confirmed] — the IEEE MA-S registry 70B3D5A9A

Historic note

00:0A:0D traces to FCI (Framatome Connectors International), acquired by Amphenol in January 2016 for $1.275B; the Berlin address reflects Amphenol's post-acquisition rename [Likely] — designworldonline.com/amphenol-completes-acquisition-of-fci

Registration date

Unknown — IEEE's MA-L registry/oui36.csv publish no assignment date; third-party "registered" dates are database artifacts, not IEEE facts [Confirmed] — the IEEE MA-L registry; the IEEE MA-S registry

Security note (device-level)

no CVE found in the NVD tying a vulnerability to Amphenol network hardware, as of an August 2026 search [Confirmed] — nvd.nist.gov (checked candidate CVE, unrelated Linux-kernel CIFS issue)

Security note (corporate-level)

Amphenol Corporation (parent) appeared on a ransomware group's leak site around July 2023; unrelated to any device carrying these OUIs [Likely] — breachsense.com/breaches/amphenol-data-breach

Related vendors

FCI / Framatome Connectors International (pre-2016 legal entity behind 00:0A:0D); Shanghai Amphenol Airwave Communication Electronics Co., Ltd. (antenna subsidiary); Amphenol Advanced Sensors (Kaye / Telaire brands)

Analyst note

An Amphenol-family OUI (78:A7:14, 00:0A:0D, B4:DD:E0, or the 70:B3:D5:A9:A sub-block) identifies connector, cable, antenna, or sensor hardware from one of four distinct Amphenol business units; the shared 70:B3:D5 base itself is not an Amphenol identifier.