TCP sesions 2-20

Hi,
can anyone explain to me why when udp btest working on 100 Mbit in the same moment TCP btest on 2 sesions gives only 20 Mbit speed,
when i take 20 sesions then i get 45 Mbit (test made on rb750G behind that p2p bridge )

but on some links the same tests give other results like 100Mbit udp and 50 Mbits only on 2 tcp sesions

i dont understand that thing … any ideas?

is it ‘receive’ test?..

Read this:
http://forum.mikrotik.com/t/1-5km-link-issues/55159/1