Based on old developer mailing list discussions, that device may be problematic and may require older OEM firmware first...
https://lists.openwrt.org/pipermail/openwrt-devel/2016-May/041541.html
That is also mentioned at the bottom of the device wiki page (which you linked in your first message):
Based on the text there, you may be better off with OEM firmware:
need to downgrade original FW first to version 1.0.00 (get FW_E1700_v1.0.00.081_20131220.bin at https://db.tt/m95cTvHq, md5sum: 68f9f63de22d508bdd699a749bcdc2d0). Ports comming up as 100mbit rather than gigabit. Wifi appears weak or incomplete, have not been able to select antenna.