port forward done but internet still disconnect *Help*

[lois19frend]

I have a u.s.robotics 8054 cable router,connect 2 pc (both ethernet),i use bitcomet 0.68,telewest 2 mb broadband, i choose listen port 49163,and max upload-20kbs,max download- no limit,max tasks-5,enable DHT,uncheck the upnp port mapping

i don't think i have a static ip,because my DNS and default gateway is-192.168.123.254,there should be 2 set of different numbers, i tried to set the router virtual server setting anyway,i put the listen port 49163 in both private/public ,and LAN server is- 192.168.123.254

when i goto TCP(IP) properties ,a dot in the obtain ip address automatically,is that mean i don't have a static ip ?

Then i open bitcomet and try to DL something,internet connection disconnect after 2 mins,so i go back to connection in bitcomet preferences to CHECK the upnp port mapping,the internet connection seems to last longer and i can only dl 1 task at a time,if i start a second task it will disconnect again ,at the moment (12 hrs later)it disconnect about 3 times.

could you please show me how to do , i did check the Q&A to find the answer,but i am not sure if i have a static ip.

what else i need to do,please help

many thanx