How can I route a WAN PC(softphone) to access my LAN PBX?

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[iomega55]

PC(branch)
IP=192.168.2.3/24
VPN_IP=10.1.1.157/24
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INTERNET
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EFW(Community 2.2rc1)
GREEN=10.1.1.66
RED=221.146.56.25
GATEWAY=221.146.56.24
OPENVPN(DHCP)=10.1.1.157/10.1.1.177
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3COM SWITCH(VLANs)  ---- PC(LAN) Data VLAN IP=10.1.1.25/24  IP2=11.1.1.36/24 
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PBX(11.1.1.254/24)
Voice VLAN

a) We want to install softphones in the branches for having IP telephony

b) How can I configure EFW for having the access to the PBX from the PC(branch) by the openvpn client. I think we need to
establish an static route, but I dont know how to do this

c) In the LAN if I configure an IP2 for the PC(LAN) I can reach the PBX, so my softphone works ok. If I delete this IP2 I
cannnot reach the PBX

d) The connection is over the VPN. We establish the VPN using openvpn. We can do everything ok from the branch for the Data
section, ie the network 10.1.1.x, but we dont have access to the Voice section(11.1.1.x).

e) We thought if we define the openvpn IP pool for the range 11.1.1.157 to 11.1.1.177, the openvpn server would serve IPs
for the Voice section, but EFW doesnt allow a range different from 10.1.1.x