Helo everyone!
I have decided to play around with MPLS little bit. found few posts on mikrotik wiki, documented part is clear enough.
Confusing part starts with MTU size settings. As I found on forum, important is to use Max possible MTU hardware is supporting.
Can anyone clarify whitch parameters needs to be changed?

my currend network setup:
RB2011 <---> Nanostation M5 <----> Nanostation M5 <---> RB750UP <---> SXT <---> SXT <--> RB450

Do I have to change MTU size on ethernet interfaces on routers? Radio links are transparent bridges? for Nanostation changing MTU is simple field in network section. For SXT do I have to change MTU just for Bridge or for all interfaces?

I dont think you benefit anything with MPLS on such setup IMHO...

Using MPLS would make sense if you had Meshed network.