ITU-T Recommendations

Recommendation ITU-T H.460.23 enables an ITU-T H.323 endpoint residing behind a NAT/FW device to report NAT/FW characteristics to the gatekeeper. When used with Recommendation ITU-T H.460.24, a gatekeeper may utilize NAT/FW information in order to formulate a decision as to how to enable direct media flow between two devices. In most cases, following these procedures will allow the gatekeeper to avoid the need for a media proxy as described in Recommendation ITU-T H.460.19, as media can be successfully transmitted directly between two endpoints residing behind distinct NAT/FW devices.Amendment 1 adds the ability for endpoints to advertise to the Gatekeeper support for H.460.24 Annex B (included in Recommendation H.460.24 Amendment 1).