OpenWRT seems to working but canot be configured

I installed openwrt on TP-Link TL-WR841ND v11. When it booted, lock diode didnť tu off (when on router was standart firmware led rued off after boot) and leds indicated coected computers show.

I can: ping the router, communicate by switch between computers

I cant: access router web GUI, access telnet

Is there any way to configure router? It seems like it works by canť access any configuration interface.