Seem many ppl confuse about wat the p2p has done to thier router , actually the problem is nop come from bandwidth. U may wonder y even i dl with bitcomet juz using 30kb/s but my router aslo cannot browse web and even hang up , izit the max bandwidth of ur ISP juz can go for 30kb/s , hv a think .

The problem is because of  NAT table in router , when we open p2p software , each connection that we had connect to other peer will eat 1 slot of NAT table(connection include with the peer that u cannot dl from them ) , normally router juz support up to 1028 slot in NAT table(but the router is set to 100<slot<500 default factory) , when the NAT table is full , then we cannot do anything else

Ex  of NAT table     

Slot------------ip-------------------port----------------OutgoinIP---------------WAN
  1---------192.168.1.2-----------50001----------202.123.123.44--------60.xx.xxx.xx
  2---------192.168.1.2------------80-------------202.123.344.55--------60.xx.xxx.xx
  .--------------.---------------------.------------------------.----------------------.------
  .--------------.---------------------.------------------------.----------------------.------                     
  .--------------.---------------------.------------------------.----------------------.------                           
  .--------------.---------------------.------------------------.----------------------.------                                           
1028-------192.168.1.3-----------65000---------60.123.123.123--------60.xx.xxx.x

*192.168.1.2 or 192.168.1.3 is the device that connect to the router ( u or ur fren pc)
*Port 50001 is example of port from bitcomet
*Port 80 is Http port , need for browse
*OutgoinIP is U get connect from who (peer or server)
*WAN is Ur ISP

When u fill up until 1028 slot then ur router will goin to block all other connection mean ur dl will keep with certain peer only (that y ur dl y keep so slow) , then u cannot browse because the slot had fill up with the BT ( that u call hang , u will realise y my connection of router , modem to ISP is on but i cannot browse?). Or even BT down to 0 dl with critical problem of NAT.

So bandwidth management juz can done by if ur router is beyond the NAT but 100% , NAT problem will come b4 bandwidth .
Mb u shd use sevice block like block the certain ip add with the port number start wiv 1000 untill 65534(coz normally ppl wont use port number under 1000 right? and the max port range is 65534)  . Then it can prevent them make connection to port and peer mean ur NAT table slot is free to u only HAHAHAHAHAHA

If u wan to know more try the article i post here . I dint read the article but it is to proof wat i am saying .
[attachmentid=270185] [attachmentid=270186]

*So far i know that DD-WRT or other 3rd party firmware support up to 4k NAT slot , mb it will  solve ur problem or mb nop ( depend ur p2p connection )