SIP-ALG is supposed to simplify the life of SIP devices behind NAT/PAT and it works by rewriting relevant SIP headers and SDP session information with the public IP address of the router and the port used.
When SIP traffic is encrypted using TLS, routers cannot perform any manipulation of packets so that devices using TLS are not affected. This is why all Wildix users experience less problems while connecting remote devices and an a higher level of security.
Continue reading “SIP-ALG, the underestimated VoIP Enemy”