ITU-T

Any device whose MAC address begins with 00:19:A7 has a network interface built by ITU-T. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

00:19:A7

Organization

ITU-T

Address

Place des Nations Geneva 20 CH CH-1211

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.