[GRT-504] What is the difference between GRT-501 and GRT-504?

GRT-501 and GRT-504 are both G.SHDSL.bis routers and comply with ITU-T G.991.2 standard. The GRT-501 is 2-Wire with one LAN port router and speed up to 5.7Mbps. The GRT-504 is 4-Wire with four LAN ports router and speed up to 11.4Mbps. Also, the GRT-504 has more advanced functions such as SPI firewall and IP QoS. For more detail information about GRT-504, please check our Web site http://www.planet.com.tw/en/product/product_ov.php?id=20381.