USING AUTHENTICATION TOKENS TO AUTHORIZE A FIREWALL TO OPEN A PINHOLE
Techniques are described for the use of a cryptographic token to authorize a firewall to open a pinhole which permits certain network traffic to traverse firewalls. An initiating endpoint requests a token from a call controller, which authorizes a pinhole though the firewall. In response, the call controller may generate a cryptographic authorization token (CAT) sent towards the destination endpoint. The call controller may generate the token based on an authorization ID associated with the call controller, a shared secret known to both the call controller and the firewall, and data specific to the media flow for which authorization is requested.