Torrent slow on MWAN3

I have aggregated 2 120mbps connection for a total throughoutput of 240mbps and verified this via speed tests.
Whenever I start a upnp using torrent download on any device the active connections reach high values like 10000 in a while and the download is utterly slow to the tune of 20mbps.
Is this a known issue? What can I do to solve it?

with openwrt or torrents ?

don't DL using torrents ...

Sorry for being nonspecific but I used the term torrent for the bit torrent protocol. I need to host some files and share them using the said protocol so I use upnp and this is what causes the high number of connections.