Zyxel GS1900-10HP
The GS1900-10HP is a 8 + 2-port Gigabit L2 switch with up to 77 Watts of PoE power on the 8 Gigabit ports.
Hardware
- RTL8380M SoC
- Macronix MX25L12835F (16MB flash)
- Samsung K4B1G0846G (128MB DDR3 SDRAM)
- 2 x RTL8231 GPIO extenders to control the port LEDs, system LED and reset button
- ST-Micron 32F100 ARM microcontroller for SoC-PoE management
- Broadcom BCM59121B0KMLG PoE controller
2 Uplink ports are SFP cages which support 1000 Base-X tmini GBIC modules.
Power is supplied via a 54V 2A barrel connector. At the back is a hard power-on/off switch and at the right side behind the grid a hard reset button and a UART serial connector. A Serial header can be connected to from the outside of the switch trough the airvents with a standard 2.54mm header. Pins are from top to bottom Vcc(3.3V), TX, RX and GND. Serial connection is via 115200 baud, 8N1.
PoE is controlled by a Broadcom BCM59121B0KMLG via a ST-Micron 32F100 ARM microcontroller, which in turn talks a serial protocol with the RTL8380M (19200 baud, 8N1). The exchange between the ARM microcontroller and the RTL SoC can be snooped by connecting a logic analyzer to pins 21 (PB10) and 22 (PB11) of the STM 32F100 in its LQFP48 package.
J3 with 2 populated pins directly behind the right airvents has unknown function. J5, marked MCU is likely to be an ARM 4-pin SWD debug header for the ST-Micron microcontroller.
Board details
| Device revision | Picture |
|---|---|
| v1 |  |
| v2 |  |
Firmware
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 complete hardware support in an experimental OpenWrt branch. Of the L2 features, port isolation, 4096 VLANs, Local Port Mirroring, EEE are supported. There is support to do a basic configuration of PoE, advanced features such as prioritizing power for ports is not supported so far. Media change is detected on the SFP cages for fibre optic cables, however after hot-swapping an SFP module, manual setup is needed. There is no support to read the SFP ID/Sensor data via I2C. Original features such as cable integrity tests, offloaded remote mirroring and Port-ACLs are not yet supported.