DTE vs DCE

(Refer from the http://www.infocellar.com/cable-dsl/dte-vs-dce.htm)

Actually, DTE and DCE are different for the pin definitions of the connecting-interface. For the case of Ethernet scenario. In the DTE, port 1,2 are transmitted port, port 3,6 are received port. In the DCE, port 1,2 are received port, port 3,6 are transmitted port.
Cardinal Rule

DTE-DCE or DCE-DTE connections use Standard Ethernet Cable (straight-thru)
DTE-DTE or DCE-DCE connections use crossover Ethernet Cable (send/receive "cross over")
DCE/DTE refer to interfaces - not the actual device. A device can have both DCE and DTE ports. However, in general:

PC LAN cards (NIC - Network Interface Card) are DTE
Hub LAN ports are DCE
Hub Uplink Ports are DTE - it is a shared port with the last LAN port, but has the pinouts crossed
Cable Modem LAN port is DCE
Router LAN ports are DCE
Home Router WAN Ethernet ports are DTE

Almost all the WAN ports of CPE (Customer-premises equipment) device are DTE. All the LAN port of CPE devices are DCE.