Hi all.
can I open RB951G-2hnd box and add external antenna in ch1 or ch0?
If it possible,can I config it in router os?
thanks.

No, rb951G don´t support external antena

thanks.
but what's this on board?

These connectors are probably only measuring points for testing/diagnostic purposes.

Maybe an official answer would be in place.
No one ever puts expensive connectors on a PCB for testing purposes since a pad for a needle adapter would suffice.

Actually, those sort of test connectors are fairly common. Just look at most smart phone boards.

The reason for the connector, it to interrupt the connection to the antenna while testing. A simple pad won't allow that.

There do appear to be solder pads for MMCX connectors directly below those test points, so a connectorized version could be in the works.

--Eric