Chapter 8 Network Address Translation (NAT)
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The SIP ALG allows SIP calls to pass through NAT by examining and translating IP addresses
embedded in the data stream. When the Router registers with the SIP register server, the SIP ALG
translates the Router’s private IP address inside the SIP data stream to a public IP address. You do
not need to use STUN or an outbound proxy if you enable the SIP ALG.
Figure 51
Network Setting > NAT > ALG
Table 42
Network Setting > NAT > ALG
LABEL
DESCRIPTION
ALG
Enable this to make sure SIP (VoIP) works correctly with port-forwarding.