A method for communicating video data between at least a first host and a second host comprises: identifying, at a server, an address of the first host, to which the second host may communicate video data, and a sequence number expected by a network security system coupled between the first host and the server; and communicating, from the second host to the first host, video data using the address of the first host and the sequence number expected. The method may further comprise: identifying, at the server, an address of the second host, to which the first host may communicate video data, and a second sequence number expected by a network security system coupled between the second host and the server; and communicating, from the first host to the second host, video data using the address of the second host and the second expected sequence number. The second host may be adapted to perform the act of communicating without use of an intermediate server. The method may also further comprise communicating periodically, from the first host to the server, through the network security system, so as to maintain an open communication channel through the network security system to the first host at the address of the first host. The address of the first host may include address information and port information.