What this means
The IEEE assigned the MA-L block B061A9 to YEALINK(XIAMEN) NETWORK TECHNOLOGY CO.,LTD.. Every network interface they manufacture under this block has a MAC address beginning with these digits, followed by a unique per-device identifier. If a device on your network shows a MAC starting B0:61:A9, it is YEALINK(XIAMEN) NETWORK TECHNOLOGY CO.,LTD. hardware.