Utilized existed BPX, using Aliwei modulization or fixed analog gateways, connect FXO ports of Aliwei gateways to PBX. Use the relay lines connected with analog gateway as number select successively, to make dialing easy. Set MCU to support telephone conference.

In province post office, connect Aliwei EID3000 modulization analog gateway with PBX. Set a GK module in Aliwei EID3000 modulization analog gateway as top GK for address resolution and router function of the calls between every GK in whole province post system.

In City post office, if there existed PBX, connect with Aliwei EID3000 modulization analog gateway. Set a GK module in Aliwei EID3000 modulization analog gateway as sub GK for address resolution and router function of the calls between every GK in whole city post system..

County post office may set 4 to 32 ports analog gateway according the need.