nixCraft

Hi! We are setting up a VPN through which employee can take customer voice calls using the internet based VPN connection and VoIP solution of Nortel Softphone. When we are making a Bridge connection the voice traffic is going smooth from both inwards and outwards NICs. But the problem arises when we implement NATing. We have setup IPtables rule for NATing as under:
# Translate incoming connections to the private server addresses
iptables -t nat -I PREROUTING 1 -d 192.168.XXX.XXX -i ETH01 -j DNAT --to-destination 10.XXX.XXX.XXX

# Translate outgoing connections from the private server addresses
iptables -t nat -I POSTROUTING 1 -s 10.XXX.XXX.XXX -o ETH01 -j SNAT --to-source 192.168.XXX.XXX

With Nating, it is possible for us to send the agents voice to a calling customer but the voice traffic from customer is not coming to the agents PC, i.e. only 1-way voice communication is happening.

Please suggest if we can do something about it.
Also, while researching about the same, I came across QoS setup on Zeroshell firewall... which I din't really understand. Anybody if temme about Qos too, and if it's related to voice traffic and NATing.

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