H460

The substandards of the ITU standard H.460 (H.460.17, H.460.18, H.460.19) describe video communication over IP networks. The H.460 standards make it easier to overcome firewalls for visual data communication over IP networks. The H.460.17, H.460.18 and H.460.19 standards are intended to unify network address translation( NAT) in visual data exchange.

H.460.17 was originally called" RAS over H.225" and clarifies that RAS messages were tunneled together with Q.931 messages. The deployment scenario for H.460.17 can be thought of as a TCP connection between a terminal and a gatekeeper that handles H.323 siganlization.

H.460.18 enables videoconferencing devices to establish connections with other end devices based on H.323, even if they are behind a firewall.

H.460.19 extends the H.323 standard by specifying a new definition for the NAT firewall mechanism. This turns on a signal redirection mechanism when audio-visual data is transmitted, such as H.460.18. This technology allows companies, for example, to communicate with customers, suppliers and employees via video-over-IP despite an internal firewall.

The H.460 standards, based on Tandberg's Expressway technology, address the problems that have caused H.323-based video communications to pass through firewalls and network address translation (NAT). When an in-house videoconferencing system logged on to a public videoconferencing server, the internal IP address could not be assigned.

Both H.460 standards rely on H.323 and route the video data through the firewall.