$ 0 0 Hi, Thanks, you're spot on ! I found these juniper articles after searching for STUN protocol and persistent NAT: https://www.juniper.net/documentation/en_US/junos15.1x49/topics/concept/nat-security-source-persistent-nat-understanding.html http://www.juniper.net/documentation/en_US/junos15.1x49/topics/example/nat-security-source-persistent-nat-with-address-pool-configuring-cli.html https://www.juniper.net/documentation/en_US/junos12.1x47/topics/concept/nat-security-source-session-traversal-utilities-for-nat-protocol-understanding.html