user manual
Grandstream Networks, Inc.  GXP21xx User Manual  Page 5 of 41 
                 Firmware version: 1.0.1.66         Last Updated: 05/2011 
FIGURE 1: CONNECTING THE GXP2120/2110 AND THE GXP EXTENSION 
 GXP2120 with GXP Extension 
GXP Extension 
Connecting the GXP2120/2110 
to GXP Extension 
Reverse side of connection with 
connection plate 
 Reverse side of connection w/connection 
 plate 
GXP2120/2110 has a special port on 
the back.  
Connect the first GXP EXT to the GXP2120/2110 using the connection cable found in the GXP Extension 
package. The first GXP EXT draws power directly from the phone. Connect the second GXP Extension unit 
using the connection plate and the connection  cable. The GXP2120/2110  will automatically reboot and 
power up the GXP Extensions. Grandstream recommends, though not required, to use a separate power 
supply with the second GXP EXT.   
NOTE: Should your system lose power, please unplug your devices and power up the GXP2120/2110 first. 
Powering up the system:   
1.  The GXP2120/2110 will boot up first;  
2.  The GXP2120/2110 LEDs will be solid red; 
3.  The status light in the top right corner of the GXP Ext will blink in red; 
4.  All of the LED indicators on the GXP Ext will flash three times; 
5.  The status light at the top right corner of the GXP Ext will turn to solid green. 
NOTE: 
1.  Extension for GXP2120/2110 is the same for GXP2020/2010 models. However, GXP2120/2110 
uses a different-shaped connector for the special port (as shown above). Extension cables will be 
included with the extension board. 
2.  Extension for GXP2120/2110 does not support hot-swap. Once connected, user should reboot the 
phone to ensure the set up will work correctly.  
3.  GXP2120/2110 can drive 2 extension modules. Independent power adapters are not needed for 
extension modules.  










