Hi to all!
I have very strange situation in my wireless network. We have 5 routers in chain, RB1-RB5.
Four routers are Groove (RB1,RB2,RB3,RB4) and one is RB2011 (RB5).
Routers are connected in this way and on all wifi link we use nv2 protocol:
RB1 - wifi - RB2 - ethernet - RB3 - wifi - RB4 - ethernet - RB5
TCP RX Speed between RB1 and RB4 is 75 MBps…
TCP TX speed between RB1 and RB4 is 80 MBps…
The strange situation iz last router RB5 that is connected ethernet cable to RB4.
TCP RX Speed between RB1 and RB5 is 25 Mbps..
TCP TX speed between RB1 and RB is 79 Mbps..
TCP RX Speed between RB4 and RB5 is 95 MBps…
TCP TX Speed between RB4 and RB5 is 95 MBps…
We lost idea’s how to fix this problem.. 
Thanks on all answers.