Which company owns MAC address prefix 78:E9:CF?

MAC address prefix 78:E9:CF is registered to TELLESCOM INDUSTRIA E COMERCIO EM TELECOMUNICACAO in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 78:E9:CF has a network interface built by TELLESCOM INDUSTRIA E COMERCIO EM TELECOMUNICACAO.

How do I find the manufacturer of a MAC address?

Take the first three octets of the address — in 78:E9:CF:00:00:00 that is 78:E9:CF — and look that prefix up in the IEEE OUI registry. If the second-lowest bit of the first octet is set, the address is locally administered (a randomized or private MAC), which belongs to no manufacturer and will not resolve; modern phones and laptops use these by default on each network.

How many MAC prefixes does TELLESCOM INDUSTRIA E COMERCIO EM TELECOMUNICACAO own?

TELLESCOM INDUSTRIA E COMERCIO EM TELECOMUNICACAO holds 9 OUI prefixes in the IEEE registry, of which 78:E9:CF is one. A device made by TELLESCOM INDUSTRIA E COMERCIO EM TELECOMUNICACAO could carry a MAC address from any of them.

TELLESCOM INDUSTRIA E COMERCIO EM TELECOMUNICACAO

MAC address prefix 78:E9:CF is registered to TELLESCOM INDUSTRIA E COMERCIO EM TELECOMUNICACAO in the IEEE OUI registry. Any device whose MAC address begins with 78:E9:CF has a network interface built by TELLESCOM INDUSTRIA E COMERCIO EM TELECOMUNICACAO. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address — it covers every MAC from 78:E9:CF:00:00:00 to 78:E9:CF:FF:FF:FF.

OUI prefix: 78:E9:CF
Hyphen form: 78-E9-CF
MAC range: 78:E9:CF:00:00:00 – 78:E9:CF:FF:FF:FF
Addresses in block: 16,777,216
Organization: TELLESCOM INDUSTRIA E COMERCIO EM TELECOMUNICACAO
Address: Av. Buriti, 1900 – Setor B – Distrito Industrial Manaus Amazonas BR 69075-000
Source: IEEE OUI registry

Have a full MAC address? Look it up— we'll also tell you if it's a randomized (private) address rather than a real manufacturer prefix.

Other prefixes from TELLESCOM INDUSTRIA E COMERCIO EM TELECOMUNICACAO

TELLESCOM INDUSTRIA E COMERCIO EM TELECOMUNICACAO holds 9 OUI prefixes in total. A device with this exact prefix could just as well carry any of these:

Assignment history (2)

The IEEE registry publishes current state only — this is the change record we've kept since we started tracking it daily.

2022-07-11Assigned to "TELLESCOM INDUSTRIA E COMERCIO EM TELECOMUNICACAO"
archived source →
2026-07-17Assigned to "TELLESCOM INDUSTRIA E COMERCIO EM TELECOMUNICACAO"

Nearby in the registry

The prefixes assigned immediately before and after 78:E9:CF:

FAQ

Which company owns MAC address prefix 78:E9:CF?: MAC address prefix 78:E9:CF is registered to TELLESCOM INDUSTRIA E COMERCIO EM TELECOMUNICACAO in the IEEE Organizationally Unique Identifier (OUI) registry. Any device whose MAC address begins with 78:E9:CF has a network interface built by TELLESCOM INDUSTRIA E COMERCIO EM TELECOMUNICACAO.
What is the OUI 78:E9:CF?: 78:E9:CF is an Organizationally Unique Identifier — the first three octets (24 bits) of a MAC address, assigned by the IEEE to TELLESCOM INDUSTRIA E COMERCIO EM TELECOMUNICACAO. It covers every address from 78:E9:CF:00:00:00 to 78:E9:CF:FF:FF:FF, or 16,777,216 addresses in total. It is also written 78-E9-CF.
How do I find the manufacturer of a MAC address?: Take the first three octets of the address — in 78:E9:CF:00:00:00 that is 78:E9:CF — and look that prefix up in the IEEE OUI registry. If the second-lowest bit of the first octet is set, the address is locally administered (a randomized or private MAC), which belongs to no manufacturer and will not resolve; modern phones and laptops use these by default on each network.
Where is TELLESCOM INDUSTRIA E COMERCIO EM TELECOMUNICACAO located?: TELLESCOM INDUSTRIA E COMERCIO EM TELECOMUNICACAO is listed at Av. Buriti, 1900 – Setor B – Distrito Industrial Manaus Amazonas BR 69075-000 in the IEEE OUI registry entry for 78:E9:CF. This is the address the organization registered with the IEEE, which may differ from its current operating address.
How many MAC prefixes does TELLESCOM INDUSTRIA E COMERCIO EM TELECOMUNICACAO own?: TELLESCOM INDUSTRIA E COMERCIO EM TELECOMUNICACAO holds 9 OUI prefixes in the IEEE registry, of which 78:E9:CF is one. A device made by TELLESCOM INDUSTRIA E COMERCIO EM TELECOMUNICACAO could carry a MAC address from any of them.