Loading...
H.323 Signaling
TCP port 1720 is primarily used for H.323 call signaling, a protocol suite widely employed for real-time voice, video, and data conferencing over IP networks. It manages the setup, control, and termination of interactive communication sessions, enabling interoperability across diverse VoIP and multimedia conferencing equipment. This port facilitates the initial connection negotiation between endpoints before media streams are established..
Overview: Port 1720 is designated for H.323 call signaling, part of the ITU-T H.323 suite which defines standards for audio, video, and data communications over packet-switched networks like LANs, WANs, and the internet. H.323 provides protocols for session setup, control, media transport, and supplementary services.
Call Setup Process: H.323 uses port 1720 to initiate TCP-based signaling via the H.225 protocol for call setup and teardown. The endpoint sends a Q.931 signaling message over TCP/1720 to the remote device or gatekeeper, negotiating session parameters and capabilities. Once established, additional control protocols such as H.245 are used (which may be reassigned to dynamic ports) to negotiate media channel properties.
Infrastructure Components: Key H.323 elements include Terminals (endpoints), Gatekeepers (for control and address resolution), Gateways (interworking with other networks), and Multipoint Control Units (MCUs) for conferences. Communication starts over port 1720, with media streams typically using dynamically negotiated UDP ports for RTP.