25km? At this distance, if both radios are perfectly configured and aligned (and Fresnel Zone respected), you can reach 180Mbps @ 20MHz + 20MHz with 5GHz-n with NV2
Now the antennas are correctly aligned, the signal strength is ~59dbm, my problem basically was resolved when I activate the chan1 in both sides TX/RX.
Check the fresnel, i have a link that is in the same conditions, but with a capacity of 95/95 Mpbs or 190 Mpbs agreg. (limited by a poe patch panel 10/100Mpbs). The CCQ is about 95% and the signal -57dbm. the antennas are 30DBi dishes, without radome and shields.