SignalWire does not publish a static list of IP addresses. Customers should periodically resolve the following domains and update their firewall rules accordingly:

dig sip.signalwire.com | egrep ^sip | awk '{ print $5 }' | xargs -n1 -I{} iptables -A INPUT -s {} -j ACCEPT

dig relay.signalwire.com | egrep ^relay | awk '{ print $5 }' | xargs -n1 -I{} iptables -A INPUT -s {} -j ACCEPT

dig firewall.signalwire.com | egrep ^firewall | awk '{ print $5 }' | xargs -n1 -I{} iptables -A INPUT -s {} -j ACCEPT

Use domain-based authorization rather than hardcoded IPs — addresses are subject to change. Media originates from a wide variety of locations and is non-deterministic.