This is an old revision of the document!
Zyxel GS1900-48
The GS1900-48 is a 48 + 2-port Gigabit L2 switch with 48 gigabit ports. 2 Uplink ports are SFP cages which support 1000 Base-X tmini GBIC modules. It has an RTL8393M SoC with 2 built-in SerDes for SFP. There are 6 RTL8218B PHYs and two RTL8231 GPIO extenders to control the port LEDs, system LED and reset button. Power is supplied via a 230 volt mains connector. The board has a hard reset switch SW1, which is is not reachable from the outside. J4 provides a 12V RS232 serial connector which is connected through U8 to the 3.3V UART of the RTL8393. Conversion is done by U8, a SIPEX 3232EC. To connect to the UART, wires can be soldered to R603 and R602.
It ships with a bootloader based on Realtek's SDK for RTL83xx SoCs and Linux 2.6 based on Realtek's SDK. It has a web interface for all management functions.
OpenWRT Support
There is experimental hardware support for the device in OpenWRT. SFP does not work.