Signalingprotocollen

Signalingprotocollen are protocols that control the signaling messages exchanged between network elements to establish and manage communication sessions. They differ from data transport protocols by focusing on control information rather than payload.

They operate across different networks, including traditional public switched telephone networks (PSTN), voice over IP, mobile networks, and multimedia services. They orchestrate registration, call setup, resource allocation, routing, handovers, and termination, and often interact with media protocols to coordinate media streams.

Common examples include SIP (Session Initiation Protocol) for initiating multimedia sessions; SS7 and ISUP in legacy telephone networks; Diameter and RADIUS for authentication, authorization, and accounting in IP networks; MGCP and Megaco (H.248) for media gateway control; H.323 as a legacy signaling standard; SIGTRAN for transporting SS7 signaling over IP.

Architecture considerations: signaling often runs on its own plane, using signaling servers, proxies, gateways, and registries; protocols may use transport layer options such as TCP, UDP or SCTP (e.g., SIGTRAN uses SCTP). Security considerations include encryption (TLS, IPsec), authentication, integrity, and protection against signaling storms and spoofing. Interoperability and interworking between different protocol families remain important.

The field continues to evolve with 5G and cloud-native networks, where signaling becomes more distributed and virtualized, with new protocols and service-based architectures.