Jiangsu Best Tone Information Service Co., Ltd

Any device whose MAC address begins with 30:A3:B5 has a network interface built by Jiangsu Best Tone Information Service Co., Ltd. This prefix (the OUI, or Organizationally Unique Identifier) is assigned by the IEEE and is the first three octets of the address.

OUI prefix

30:A3:B5

Organization

Jiangsu Best Tone Information Service Co., Ltd

Address

No.501,Zhongshan South Road Nanjing Jiangsu CN 210006

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.