Article Details

Abstract

To address the multi-protocol adaptation problems faced by boundary nodes in signaling processing, media forwarding, and security protection in private multimedia communication scenarios, a secure multi-protocol SBC system based on Kamailio and RTPengine is designed and implemented. The system adopts a collaborative signaling and media processing architecture. Through dual network interfaces, internal and external network domain separation and boundary control are accomplished. On the signaling side, the system supports UDP, TCP, and TLS access. On the media side, it supports SRTP-encrypted transmission and DTLS-based key negotiation. The implementation and verification focus on SIP session establishment, SDP negotiation, media path control, and secure media processing. Packet capture results show that SIP messages with different transport modes at the terminal side can be adapted into a backend-processable UDP link at the SBC boundary, and that media parameter negotiation and bidirectional media transmission can both be completed normally in SRTP and DTLS-SRTP scenarios. The system is applicable to private multimedia communication scenarios requiring boundary isolation, protocol adaptation, and secure access.

Keywords

Session Border Controller; Session Initiation Protocol; multi-protocol transmission; secure transmission; media proxy; network boundary control; encrypted communication

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About the authors

Li Chunfei (1989-), male, Han ethnicity, from Zhangjiakou, Hebei Province, China, intermediate engineer, bachelor's degree, research direction: multimedia communication and network boundary security.