ALLWIN's VoIP GW supports the following CODEC simultaneously.
-G.711 A-law / u-law (64kbps)
-G.723.1 (5.3 or 6.3kbps)
-G.726 (ADPCM 40, 32, 24, 16 kbps)
-G.729a/G.729b (8kbps)

ALLWIN's VoIP GW supports H.323&SIP simultaneously.

No, there is no any limitation on it, just connect the standard analog telephones (pots phone) to FXS interfaces of GWs.

First, please open your IE browser and key in the factory default IP address of http://192.168.22.1 in the URL bar.

After that, please key in the default user name of voip, default password of 1234, then you will be taken to the Web UI when you have successfully logged in as the administrator.

The G3000C VoIP Router includes FXS and PSTN interface; the Pin 2 and Pin 3 of telephone interface connected to PSTN line, and the Pin 1 and Pin 4 connected to pots phone or PBX CO line.

FXS:
An FXS interface provides -48 VDC power and generates ring signals, connects to standard analog telephones or PBX central office line normally.

FXO:
An FXO interface receives -48 VDC power and receives ring signals, connects to PSTN line or PBX extension normally.

FXS interface can not be connected to another FXS interface, and must not be connected to PSTN line or PBX extension,
Otherwise it will cause devices damaged; FXS just can be connected to digital PBX central office line.