How about WAN IP address of TL-WR1042ND? If it is a private one, you need to open ports on your modem for the router as well.

Mine is about 550KBps (4.4Mbps). It is a normal speed because of big difference in processors of ordinary PC and wr2543ND. Ordinary PC---2.0GHz TL-WR2543ND---400MHz

Hi Grzegorz, Printer server funcion cannot be applied on Linux OS. There is no compatible software for it. http://www.tp-link.com/en/support/download/?model=TL-WDR4300&version=V1#tbl_b The utility is...

No option there to configure a channel. I am afaid cannot. :(

When the laptop disconnects, you may try to access internet with a network cable to wa830. " if i reset the router at 2nd floor, everthing normal again." Your belkin router? Restart or reset? If...

It restarts itself? Did you ever try a different wall socket or power adatper? Just reset to factory default settings. If the same, probably, it is faulty.