Patent ID: 8200827

Claim:
A method for routing voice packets across multiple security zones, the method comprising: performing, with a firewall, call setup signaling across at least a first security zone, a second security zone, and a third security zone to set up a call through the firewall between a first user device in the first security zone and a second user device in the third security zone, where setting up the call includes: receiving, with the firewall, a call invitation message from the first user device in the first security zone, where the call invitation message includes private addressing information comprising: a source address, associated with the first user device, included in a header of the call invitation message, and address information, associated with media to be transmitted between the first user device and the second user device, included in a body of the call invitation message, identifying, with the firewall, the private addressing information in the call invitation message, translating, with the firewall, the identified private addressing information into publicly routable addressing information, establishing, with the firewall and based on the private addressing information, at least one first gate between the first security zone and the second security zone, where the at least one first gate includes a discrete pinhole for signaling packets associated with the call and another discrete pinhole for media packets associated with the call, forwarding, with the firewall and based on establishing the at least one first gate, the call invitation message, including the publicly routable addressing information, to a proxy server in the second security zone, receiving, with the firewall, a processed call invitation message from the proxy server, where the processed call invitation message includes portions of the call invitation message, establishing, with the firewall, a link between the call invitation message and the processed call invitation message based on the included portions of the call invitation message, tearing down, based on establishing the link, the discrete pinhole for media packets, establishing, with the firewall and based on establishing the link and tearing down the discrete pinhole for media packets, at least one second gate between the first security zone and the third security zone, where the at least one second gate includes a discrete pinhole for media packets that permits media messages associated with the call to be transmitted, via the firewall, directly between the first security zone and the third security zone, and where the at least one second gate includes a discrete pinhole for signaling messages that points to the proxy server to direct signaling messages associated with the call through the proxy server, and forwarding, with the firewall, the processed call invitation message to the second user device in the third security zone.