That is the problem. It has no WAN port. Only 4 LAN ports and 1 DSL port (RJ11)
Its not possible check closely, on one of the ports (mostly first or fourth) , WAN will be written within brackets or something...
Specs page says :
CONNECTIVITY
AntennaeExternal
Number of LAN ports4
Number of WAN ports1
Number of USB Ports0
WANRJ-11
LANRJ-45[DOUBLEPOST=1389870655][/DOUBLEPOST]
Well according to this picture , the WAN port is not mentioned on the router , but there is one , manuals might help you !
Try the guides here :
http://www.tp-link.in/products/details/?model=TD-W8951ND#down
When u open the router page , during setups , there will a place to sellect ISP ..
Options will be : Dynamic IP ADDRESS , Static IP ADDRESS,PPPoA/PPPoE,Bridge Mode.
Select Dynamic IP address to use just as router , or id u are using modem in Bridge mode , then select bridge mode (advanced users).
The only problem is figuring out , which is the WAN port !